Characteristics of Puberty in a Population-Based Sample of Danish Adolescents

PURPOSE

To describe the duration, timing, tempo, and synchronicity of puberty, as well as the correlation between timing and tempo of puberty.

METHODS

Overall, 15,819 of 22,439 invited children participated in the Puberty Cohort within the Danish National Birth Cohort. Participants completed a web-based questionnaire every 6 months through maturation with questions on current pubertal status. Girls reported current Tanner stage of breast and pubic hair development, and timing of menarche. Boys reported current Tanner stage of genital and pubic hair development, timing of first ejaculation, and vocal changes. While accounting for this interval-censored puberty information, we estimated the duration of puberty. Then, we used a nonlinear mixed effect growth model to estimate timing, tempo, synchronicity of puberty, and correlation between timing and tempo of puberty.

RESULTS

In girls, the average duration of breast development was longer, whereas the average tempo was slower than pubic hair development. The average timing of breast development was earlier than the average timing of pubic hair development. The majority of girls had asynchronous puberty. In boys, the average duration was longer and average tempo slower for genital than pubic hair development. The average timing of genital and pubic hair development were comparable; hence, the majority had synchronous pubertal development. Adolescents who had earlier timing also tended to have a faster tempo.

DISCUSSION

Being one of the largest puberty cohorts worldwide, these unique contemporary data can help physicians, parents, and children to understand and anticipate expected progression through pubertal development.

Characterization of Puberty in an Australian Population-Based Cohort Study

PURPOSE

Current knowledge of the characteristics of puberty beyond age at menarche and thelarche is limited, particularly within population-based cohorts. Secular trends and concerns of the health effects of early puberty reinforce the value of contemporary studies characterizing the timing, tempo, duration, and synchronicity of puberty.

METHODS

The Childhood to Adolescence Transition Study is a unique Australian cohort of individuals followed annually from late childhood to late adolescence, with up to eight assessments of pubertal stage from 9 to 19 years of age (N = 1,183; 636 females). At each assessment, females reported their Tanner Stage of breast and pubic hair development, while males reported on genital/pubic hair development. Nonlinear mixed-effects models characterized pubertal trajectories and were used to derive each individual's estimates of timing, tempo, and synchronicity. Parametric survival models were used to estimate the overall duration of puberty.

RESULTS

Timing of mid-puberty (Tanner Stage 3) ranged from 12.5 to 13.5 years, with females developing approximately 6 months before males. Pubertal tempo (at mid-puberty) was similar across sex (between half and one Tanner Stage per year), but the overall duration of puberty was slightly shorter in males. Most females exhibited asynchronous changes of breast and pubic hair development.

DISCUSSION

Estimates of pubertal timing and tempo are consistent with reports of cohorts from two or more decades ago, suggesting stabilization of certain pubertal characteristics in predominantly White populations. However, our understanding of the duration of puberty and individual differences in pubertal characteristics (e.g., synchronicity of physical changes) remains limited.

Interpersonal Violence and Gender Inequality in Adolescents: A Systematic Analysis of Global Burden of Disease Data From 1990 to 2019

PURPOSE

Interpersonal violence is a leading cause of adolescent deaths and disability. This study investigates sex differences in burden of interpersonal violence for adolescents and explores associations with gender inequality.

METHOD

Using data from the 2019 Global Burden of Disease study, we report numbers, proportions, rates of interpersonal violence deaths and disability adjusted life years (DALYs) for all ages, and rate of change (from 1990 to 2019) in adolescents aged 10-24 years disaggregated by sex and geography. We explored associations with gender inequality using gender inequality index.

RESULTS

One in four (24.8%) all-age interpersonal violence deaths are in adolescents. In 2019, the rate of deaths in adolescent males was almost six times higher than females (9.3 vs. 1.6 per 100,000); and since 1990, the rate of decline in DALYs for females was double than that for males (-28.9% vs. -12.7%). By contrast, the burden of sexual violence is disproportionately borne by adolescent females, with over double the rate than males (DALYs: 42.8 vs. 17.5 per 100,000). In countries with greater gender inequality, the male-to-female ratio (deaths and DALYs) was increased among older adolescents, pointing to benefits for males in more gender equal settings.

DISCUSSION

Social identities, relationships, and attitudes to violence are established in adolescence, which is an inflection point marking the emergence of disproportionate burdens of interpersonal violence. Our findings affirm that global agendas must be expanded to address interrelated factors driving multiple forms of interpersonal violence experienced by adolescents and reverberating to the next generation.

Transition to Adulthood for Extremely Preterm Survivors

OBJECTIVE

To compare transition into adulthood of survivors born extremely preterm (EP; <28 weeks' gestation) or extremely low birth weight (ELBW; <1000 g) in the postsurfactant era with term-born controls.

METHODS

Prospective longitudinal cohort study of all EP/ELBW survivors born in the State of Victoria, Australia between January 1, 1991 and December 31, 1992 and matched term-born controls. Outcomes include educational attainment, employment, financial status, romantic partnering, living arrangements, parenthood, physical health and mental health, risk-taking behaviors, life satisfaction, and interpersonal relationships at 25 years.

RESULTS

Data were available from 165 EP/ELBW and 127 control participants. Overall, there was little evidence for differences between the EP/ELBW and control groups on most comparisons after adjustment for social risk and multiple births. However, compared with controls, the EP/ELBW group was more likely to have their main source of income from government (adjusted odds ratio [aOR] 2.49, 95% confidence interval [CI] 1.21-5.13; P = .01) and to have never moved out of the parental home (aOR 2.13, 95% CI 1.27-3.58; P = .01), and fewer had ever engaged in smoking (aOR 0.52, 95% CI 0.28-0.98; P = .04), binge drinking (aOR 0.41, 95% CI 0.18-0.93; P = .03), or street drugs (aOR 0.56, 95% CI 0.32-0.98; P = .04).

CONCLUSIONS

Aside from clinically important differences in main income source, leaving the parental home, and reduced risk-taking behavior, survivors born EP/ELBW in the era since surfactant was introduced are transitioning into adulthood similarly to term-born controls in some areas assessed but not all.

Towards responsive policy and actions to address non-communicable disease risks amongst adolescents in Indonesia: insights from key stakeholders

Background

Non-communicable diseases (NCDs) such as cancer, diabetes, heart disease, mental disorder and chronic lung conditions are the leading cause of death and disability in Indonesia. Adolescence is when risks for NCDs emerge and it is also an important life stage for intervention, yet young people are often at the margins of NCD policy and actions. This study aimed to understand how policies and actions should address NCD risks (tobacco smoking, inadequate physical activity, and diet) for adolescents in Indonesia, and how young people can be meaningfully involved.

Methods

Qualitative in-depth interviews over videoconference (n = 21) were conducted in English or Bahasa with stakeholders in Indonesia. Participants included policymakers, implementation partners, and advocates who were focused on adolescent health or NCDs. Interviews were recorded, transcribed, translated, and thematically analysed using NVivo12. Findings were disseminated to participants for validation and feedback. Youth participants (n = 7) attended an additional workshop and considered recommendations and actions arising from this research.

Findings

Participants identified that government and non-government organisations are acting on NCDs in Indonesia, but few of the existing initiatives target adolescents, and adolescent services rarely addressed NCD risks. Participants also felt that policies to protect adolescents from NCD risks (i.e., smoke-free areas in public) were not always enforced. For programs or initiatives focused on adolescent health, those that had engaged adolescents as co-creators and leaders were perceived to be more successful. As such, participants recommended more meaningful engagement of young people, including young people's leadership of initiatives. Additional recommendations included the need for intersectoral engagement and a 'whole-of-government' approach to prevention given the complex determinants of NCD risks, and the need for evidence-based actions that are underpinned by quality data to enable monitoring of progress.

Interpretation

There is a recognised need to strengthen policies and actions to address NCD risks amongst adolescents in Indonesia. Meaningful youth engagement that allows young people to take the lead, intersectoral actions, and evidence-based data driven responses were key strategies identified.

Funding

UNICEF East Asia and Pacific Regional Office.

Long-term trends and urban-rural disparities in the physical growth of children and adolescents in China: an analysis of five national school surveys over three decades

BACKGROUND

China's rapid economic growth has brought opportunities for improved health and growth of children and adolescents. We sought to explore the long-term trends and urban-rural inequalities in physical growth (specifically height and BMI) among school-aged children and adolescents in China to identify policy priorities for a healthier generation.

METHODS

We used the 1985, 1995, 2005, 2014, and 2019 cycles of the Chinese National Survey on Students' Constitution and Health from primary and secondary schools in 30 mainland provinces, autonomous regions, and municipalities. We analysed height and BMI data for 7, 12, and 18 year old children and adolescents of Han ethnicity. Children and adolescents who had complete data on age, sex, location, weight, and height were included. All surveys used a multi-stage stratified random cluster sampling method and were nationally representative. A univariate kernel density estimation was used to plot the distribution of height and BMI. Quantile regression was used to examine associations between urban and rural locations and the primary outcomes of height and BMI at specific quantiles of distribution (5th, 25th, 50th, 75th, and 95th).

FINDINGS

Across the five surveys (in 1985, 1995, 2005, 2014, and 2019), 313 973 children and adolescents were included. From 1985 to 2019, the height and BMI distribution curves shifted to the right for each age group and sex, with the BMI curve becoming more dispersed. Median height in adolescents aged 18 years increased by 3·8 cm (95% CI 3·4-4·1) in boys in urban areas and 5·7 cm (5·3-6·1) in boys in rural areas, and 2·7 cm (2·4-3·0) in girls in urban areas and 3·7 cm (3·4-4·0) in girls in rural areas. Children in urban areas were taller than those in rural areas at every quantile, but the magnitude of this disparity narrowed by 2019. In 2019, the median height of boys in urban areas were 1·4 cm (1·0-1·8) greater in those aged 7 years, 2·5 cm (1·9-3·1) greater in those aged 12 years, and 1·1 cm (0·6-1·5) greater in those aged 18 years than their rural counterparts, whereas the median height of girls in urban areas were 1·1 cm (0·7-1·4) greater in those aged 7 years, 1·6 cm (1·1-2·1) greater in those aged 12 years, and 1·1 cm (0·7-1·5) greater in those aged 18 years than rural girls. Over this period, urban-rural differences in BMI disappeared at the lowest quantile, but persisted at higher quantiles. In 2019, the urban-rural differences in BMI for boys aged 12 years were 0·6 kg/m2 (95% CI 0·3-0·8) at the median, 1·0 kg/m2 (0·6-1·4) at the 75th quantile, and 0·7 kg/m2 (0·1-1·3) at the 95th quantile; for girls aged 12 years, 0·3 kg/m2 (0·1-0·5) at the median, 0·5 kg/m2 (0·2-0·8) at the 75th quantile, and 0·9 kg/m2 (0·3-1·5) at the 95th quantile; for boys aged 18 years, 0·6 kg/m2 (0·4-0·8) at the median, 0·8 kg/m2 (0·5-1·2) at the 75th quantile, and 0.7 kg/m2 (0·0-1·5) at the 95th quantile; and for girls aged 18 years, 0·2 kg/m2 (0·1-0·4) at the median, 0·5 kg/m2 (0·3-0·8) at the 75th quantile, and 1·0 kg/m2 (0·5-1·5) at the 95th quantile.

INTERPRETATION

Across three decades, school-aged children and adolescents in China have increased in height and BMI, with less disparity between urban and rural locations. Investments are needed to improve the affordability of healthy foods to help children and adolescents in rural areas reach their potential maximum height. Meanwhile, these changes in BMI necessitate tailored strategies according to urban-rural settings to contain the increase in overweight and obesity and promote optimal growth for children and adolescents.

FUNDING

Capital's Funds for Health Improvement and Research, and National Natural Science Foundation of China.

Health-related quality of life in adults born extremely preterm or with extremely low birth weight in the postsurfactant era: a longitudinal cohort study

OBJECTIVES

To compare health-related quality of life (HRQoL) at 25 and 18 years in individuals born extremely preterm (EP, <28 weeks' gestation) or with extremely low birth weight (ELBW, birth weight <1000 g) with term-born (≥37 weeks) controls. Within the EP/ELBW cohort, to determine whether HRQoL differed between those with lower and higher IQs.

METHODS

HRQoL was self-reported using the Health Utilities Index Mark 3 (HUI3) at 18 and 25 years by 297 EP/ELBW and 251 controls born in 1991-1992 in Victoria, Australia. Median differences (MDs) between groups were estimated using multiple imputation to handle missing data.

RESULTS

Adults born EP/ELBW had lower HRQoL (median utility 0.89) at 25 years than controls (median utility 0.93, MD -0.040), but with substantial uncertainty in the estimate (95% CI -0.088 to 0.008) and a smaller reduction at 18 years (MD -0.016, 95% CI -0.061 to 0.029). On individual HUI3 items, there was suboptimal performance on speech (OR 9.28, 95% CI 3.09 to 27.93) and dexterity (OR 5.44, 95% CI 1.04 to 28.45) in the EP/ELBW cohort. Within the EP/ELBW cohort, individuals with lower IQ had lower HRQoL compared with those with higher IQ at 25 (MD -0.031, 95% CI -0.126 to 0.064) and 18 years (MD -0.034, 95% CI -0.107 to 0.040), but again with substantial uncertainty in the estimates.

CONCLUSIONS

Compared with term-born controls, young adults born EP/ELBW reported poorer HRQoL, as did those with lower IQ compared with those with higher IQ in the EP/ELBW cohort. Given the uncertainties, our findings need corroboration.

The forgotten girls: the state of evidence for health interventions for pregnant adolescents and their newborns in low-income and middle-income countries

Every year, an estimated 21 million girls aged 15-19 years become pregnant in low-income and middle-income countries (LMICs). Policy responses have focused on reducing the adolescent birth rate whereas efforts to support pregnant adolescents have developed more slowly. We did a systematic review of interventions addressing any health-related outcome for pregnant adolescents and their newborn babies in LMICs and mapped its results to a framework describing high-quality health systems for pregnant adolescents. Although we identified some promising interventions, such as micronutrient supplementation, conditional cash transfers, and well facilitated group care, most studies were at high risk of bias and there were substantial gaps in evidence. These included major gaps in delivery, abortion, and postnatal care, and mental health, violence, and substance misuse-related outcomes. We recommend that the fields of adolescent, maternal, and sexual and reproductive health collaborate to develop more adolescent-inclusive maternal health care and research, and specific interventions for pregnant adolescents. We outline steps to develop high-quality, evidence-based care for the millions of pregnant adolescents and their newborns who currently do not receive this.

Intervention targets for reducing mortality between mid-adolescence and mid-adulthood: a protocol for a machine-learning facilitated systematic umbrella review

INTRODUCTION

A rise in premature mortality-defined here as death during the most productive years of life, between adolescence and middle adulthood (15-60 years)-is contributing to stalling life expectancy in high-income countries. Causes of mortality vary, but often include substance misuse, suicide, unintentional injury and non-communicable disease. The development of evidence-informed policy frameworks to guide new approaches to prevention require knowledge of early targets for intervention, and interactions between higher level drivers. Here, we aim to: (1) identify systematic reviews with or without meta-analyses focused on intervention targets for premature mortality (in which intervention targets are causes of mortality that can, at least hypothetically, be modified to reduce risk); (2) evaluate the review quality and risk of bias; (3) compare and evaluate each review's, and their relevant primary studies, findings to identify existing evidence gaps.

METHODS AND ANALYSIS

In May 2023, we searched electronic databases (MEDLINE, PubMed, Embase, Cochrane Library) for peer-reviewed papers published in the English language in the 12 years from 2012 to 2023 that examined intervention targets for mortality. Screening will narrow these papers to focus on systematic reviews with or without meta-analyses, and their primary papers. Our outcome is death between ages 15 and 60 years; with potential intervention targets measured prior to death. A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) will be used to assess quality and risk of bias within included systematic reviews. Results will be synthesised narratively due to anticipated heterogeneity between reviews and between primary studies contained within included reviews.

ETHICS AND DISSEMINATION

This review will synthesise findings from published systematic reviews and meta-analyses, and their primary reviewed studies, meaning ethics committee approval is not required. Our findings will inform cross-cohort consortium development, be published in a peer-reviewed journal, and be presented at national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42022355861.

Will a fee-for-service payment for a young people's health assessment in general practice increase the detection of health risk behaviours and health conditions? Protocol for a cluster randomised controlled trial (RAd Health Trial)

INTRODUCTION

Adolescence is a period of major transition in physical, cognitive, social and emotional development, and the peak time for the onset of mental health conditions, substance use disorders and sexual and reproductive health risks. Prevention and treatment during this time can improve health and well-being now and into the future. However, despite clinical guidelines recommending annual preventive health assessments for young people, health professionals cite lack of consultation time and adequate funding as key barriers. This trial aims to determine whether a specific fee-for-service ('rebate payment') for a young person's health assessment, is effective and cost-effective at increasing the detection and management of health risk behaviours and conditions among young people.

METHODS AND ANALYSIS

This cluster randomised controlled trial will be conducted in Australian general practice. 42 general practices (clusters) will be randomly allocated 1:1 to either an intervention arm where general practitioners receive a rebate payment for each annual health assessment undertaken for 14-24-year-olds during a 2 year study period, or a control arm (no rebate). The rebate amount will be based on the Medical Benefits Schedule (Australia's list of health professional services subsidised by the Australian Government) currently available for similar age-based assessments. Our primary outcome will be the annual rate of risk behaviours and health conditions recorded in the patient electronic health record (eg, alcohol/drug use, sexual activity and mental health issues). Secondary outcomes include the annual rate of patient management activities related to health risks and conditions identified (eg, contraception prescribed, sexually transmitted infection tests ordered). A process evaluation will assess acceptability, adoption, fidelity and sustainability of the rebate; an economic evaluation will assess its cost-effectiveness. Analyses will be intention-to-treat.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from University of Melbourne Human and Research Ethics Committee (2022-23435-29990-3). Findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12622000114741.

Towards a youth mental health paradigm: a perspective and roadmap

Most mental disorders have a typical onset between 12 and 25 years of age, highlighting the importance of this period for the pathogenesis, diagnosis, and treatment of mental ill-health. This perspective addresses interactions between risk and protective factors and brain development as key pillars accounting for the emergence of psychopathology in youth. Moreover, we propose that novel approaches towards early diagnosis and interventions are required that reflect the evolution of emerging psychopathology, the importance of novel service models, and knowledge exchange between science and practitioners. Taken together, we propose a transformative early intervention paradigm for research and clinical care that could significantly enhance mental health in young people and initiate a shift towards the prevention of severe mental disorders.

Mental health in young adults born extremely preterm or extremely low birthweight with contemporary neonatal intensive care

BACKGROUND

For infants born in the contemporary era of neonatal care, little is known about adult mental health outcomes of extremely preterm birth (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g). This study aimed to compare attention deficit hyperactivity disorder (ADHD), anxiety, mood, and substance use disorder prevalence in young adults born EP/ELBW and normal birthweight (NBW; >2499 g) controls, and to compare change in prevalence of mental health symptoms and disorders from 18 to 25 years.

METHODS

Participants were a prospective geographical cohort of 297 consecutive survivors born EP/ELBW during 1991-1992 and 260 NBW controls. At age 25 years, 174 EP/ELBW and 139 NBW participants completed the Adult ADHD Rating Scale, Structured Clinical Interview for DSM-IV Disorders, Beck Anxiety Inventory, and Center for Epidemiologic Studies Depression Scale-Revised. Data from follow-up at 18 years were also utilized. Multiple imputation was used to account for attrition.

RESULTS

Mental health outcomes at 25 years were similar between groups: prevalence rates were ADHD 7% v. 5%; anxiety 32% v. 27%; mood 38% v. 35%; substance use 12% v. 14% in the EP/ELBW and NBW groups, respectively. In both groups, ADHD declined between 18 and 25 years [odds ratio (OR) per year = 0.87, 95% confidence interval (CI) 0.79-0.95], and generalized anxiety disorder and major depressive episode became more common (OR 1.22, 95% CI 1.10-1.35 per year; OR 1.20, 95% CI 1.10-1.30 respectively).

CONCLUSIONS

This contemporary EP/ELBW cohort has comparable young adult mental health outcomes to controls, and similar patterns of change in mental health from late adolescence.

Non-communicable disease mortality in young people with a history of contact with the youth justice system in Queensland, Australia: a retrospective, population-based cohort study

BACKGROUND

Young people who have had contact with the criminal justice system are at increased risk of early death, especially from injuries. However, deaths due to non-communicable diseases (NCDs) in this population remain poorly described. We aimed to estimate mortality due to NCDs in people with a history of involvement with the youth justice system, compare NCD mortality rates in this population with those in the general population, and characterise demographic and justice-related factors associated with deaths caused by NCDs in people with a history of contact with the youth justice system.

METHODS

In this retrospective, population-based cohort study (the Youth Justice Mortality [YJ-Mort] study), we included all people aged 10-18 years (at baseline) charged with a criminal offence in Queensland, Australia, between June 30, 1993, and July 1, 2014. We probabilistically linked youth justice records with adult correctional records and national death records up to Jan 31, 2017. Indigenous status was ascertained from youth justice and adult correctional records, with individuals identified as Indigenous in either source classified as Indigenous in the final dataset. We estimated crude mortality rates and standardised mortality ratios (SMRs) for comparisons with data from the Australian general population. We identified risk factors for NCD deaths using competing-risks regression.

FINDINGS

Of 48 670 individuals aged 10-18 years (at baseline) charged with a criminal offence in Queensland, Australia, between June 30, 1993, and July 1, 2014, 11 897 (24·4%) individuals were female, 36 773 (75·6%) were male, and 13 250 (27·2%) were identified as identified as Indigenous. The median age at first contact with the youth justice system was 15 years (IQR 14-16), the median follow-up time was 13·4 years (8·4-18·4), and the median age at the end of the study was 28·6 years (23·6-33·6). Of 1431 deaths, 932 (65·1%) had a known and attributed cause, and 121 (13·0%) of these were caused by an NCD. The crude mortality rate from NCDs was 18·5 (95% CI 15·5-22·1) per 100 000 person-years among individuals with a history of involvement with the youth justice system, which was higher than among the age-matched and sex-matched Australian general population (SMR 1·67 [1·39-1·99]). Two or more admissions to adult custody (compared with none; adjusted sub-distribution hazard ratio 2·09 [1·36-3·22]), and up to 52 weeks in adult custody (compared with none; 1·98 [1·18-3·32]) was associated with NCD death.

INTERPRETATION

Young people with a history of contact with the justice system are at increased risk of death from NCDs compared with age-matched and sex-matched peers in the general Australian population. Reducing youth incarceration and providing young people's rights to access clinical, preventive, and restorative services should be a priority.

FUNDING

National Health and Medical Research Council.

Weight status and weight-control exercise in adolescents: A longitudinal population-based study

OBJECTIVE

Exercise is a transdiagnostic clinical feature of eating disorders, but consensus is lacking as to what constitutes, and gives rise to, excessive exercise motivated by weight control. Using a longitudinal cohort study, we aimed to describe population-level prevalence rates of varying levels of weight-control exercise and examine gender and weight status (overweight or obesity; OVOB) as cross-sectional determinants of weight-control exercise in 14-15-year-old adolescents. We then evaluated the association of OVOB at 10-11 years with weight-control exercise at 14-15 years.

METHODS

The sample comprised 6329 adolescents from the Longitudinal Study of Australian Children (LSAC). Weight and height were measured in early adolescence (aged 10-11) and in mid-adolescence (aged 14-15). Participants reported weight-control exercise using the Branched Eating Disorders Test at 14-15 years.

RESULTS

In mid-adolescence, the estimated population prevalence for any weight-control exercise was 49 % (55 % in females). For girls, moderate levels of exercise were most prevalent, and low levels for boys. For all levels except for the very lowest, boys with (vs. without) OVOB history (10-11 years) had about twice the odds of endorsing every level of weight-control exercise. Patterns among girls were similar, though lower in magnitude (∼1.5 times).

CONCLUSIONS

For both girls and boys, across most exercise levels, rates of weight-control exercise were greatest for those with OVOB; for the highest exercise level, effects were strongest for boys with OVOB. To accurately identify at-risk adolescents, our results provide preliminary support for a fluid definition of excessive weight-control exercise, dependent on gender and weight status.

Continuities in maternal substance use from early adolescence to parenthood: findings from the intergenerational cohort consortium

BACKGROUND

This study assessed the extent to which women's preconception binge drinking, tobacco use and cannabis use, reported prospectively in adolescence and young adulthood, predicted use of these substances during pregnancy and at 1 year postpartum.

METHODS

Data were pooled from two intergenerational cohort studies: the Australian Temperament Project Generation 3 Study (395 mothers, 691 pregnancies) and the Victorian Intergenerational Health Cohort Study (398 mothers, 609 pregnancies). Alcohol, tobacco and cannabis use were assessed in adolescence (13-18 years), young adulthood (19-29 years) and at ages 29-35 years for those transitioning to parenthood. Exposures were weekly or more frequent preconception binge drinking (5 + drinks in one session), tobacco use and cannabis use. Outcomes were any alcohol, tobacco and cannabis use prior to awareness of the pregnancy, after awareness of pregnancy (up to and including the third trimester pregnancy) and at 1 year postpartum.

RESULTS

Frequent preconception binge drinking, tobacco use and cannabis use across both adolescence and young adulthood were strong predictors of continued use post-conception, before and after awareness of the pregnancy and at 1 year postpartum. Substance use limited to young adulthood also predicted continued use post-conception.

CONCLUSIONS

Persistent alcohol, tobacco use and cannabis use that starts in adolescence has a strong continuity into parenthood. Reducing substance use in the perinatal period requires action well before pregnancy, commencing in adolescence and continuing into the years before conception and throughout the perinatal period.

Parental personality and early life ecology: a prospective cohort study from preconception to postpartum

Personality reliably predicts life outcomes ranging from social and material resources to mental health and interpersonal capacities. However, little is known about the potential intergenerational impact of parent personality prior to offspring conception on family resources and child development across the first thousand days of life. We analysed data from the Victorian Intergenerational Health Cohort Study (665 parents, 1030 infants; est. 1992), a two-generation study with prospective assessment of preconception background factors in parental adolescence, preconception personality traits in young adulthood (agreeableness, conscientiousness, emotional stability, extraversion, and openness), and multiple parental resources and infant characteristics in pregnancy and after the birth of their child. After adjusting for pre-exposure confounders, both maternal and paternal preconception personality traits were associated with numerous parental resources and attributes in pregnancy and postpartum, as well as with infant biobehavioural characteristics. Effect sizes ranged from small to moderate when considering parent personality traits as continuous exposures, and from small to large when considering personality traits as binary exposures. Young adult personality, well before offspring conception, is associated with the perinatal household social and financial context, parental mental health, parenting style and self-efficacy, and temperamental characteristics of offspring. These are pivotal aspects of early life development that ultimately predict a child's long-term health and development.

Mortality among people who have experienced homelessness: protocol for a systematic review and meta-analysis

INTRODUCTION

Homelessness is a major contributor to health inequalities. People who experience homelessness are at markedly increased risk of multiple and complex health morbidities which likely increase their susceptibility to early, preventable death. Despite this, the mortality burden in this group remains poorly understood, limited in part by insufficient synthesis of data at a global level. This systematic review will synthesise international literature examining rates of risk and protective factors for mortality among people who have experienced homelessness.

METHODS AND ANALYSIS

We will search MEDLINE, PsycINFO, Embase and PubMed for peer-reviewed cohort studies examining mortality among people who have experienced homelessness. No study eligibility restrictions will be placed on the date, country of origin, or language of publications, or age of the sample. We will assess the quality of included studies using the Methodological Standards for Epidemiological Research scale. Our measures of mortality will include: (A) incidence-all cause and cause specific, expressed as a crude mortality rate (CMR) per 1000 person-years, with 95% CI and (B) all cause and cause specific, indirectly standardised mortality ratios (SMRs) with 95%CI. Associations between risk and protective factors and all-cause and cause-specific mortality will be reported using pooled relative risk ratios with 95% CI. Where there are sufficient data, the influence of subgroup and methodological factors on CMRs, SMRs and predictive factors will be examined using meta-regression.

ETHICS AND DISSEMINATION

This study does not require institutional ethics review or approval as it will synthesise findings from published studies that have previously been granted relevant ethics approvals. Study findings will be disseminated through a peer-reviewed journal article, conference and seminar presentations. A plain language summary will be distributed through the authors' academic and professional networks.

PROSPERO REGISTRATION NUMBER

CRD42021272937.

Parental history of positive development and child behavior in next generation offspring: A two-cohort prospective intergenerational study

This study examined whether positive development (PD) in adolescence and young adulthood predicts offspring behavior in two Australasian intergenerational cohorts. The Australian Temperament Project Generation 3 Study assessed PD at age 19-28 (years 2002-2010) and behavior in 1165 infants (12-18 months; 608 girls) of 694 Australian-born parents (age 29-35; 2012-2019; 399 mothers). The Dunedin Multidisciplinary Health and Development Parenting Study assessed PD at age 15-18 (years 1987-1991) and behavior in 695 preschoolers (3-5 years; 349 girls) and their New Zealand born parents (age 21-46; 1994-2018; 363 mothers; 89% European ethnicity). In both cohorts, PD before parenthood predicted more positive offspring behavior (β_range  = .11-.16) and fewer behavior problems (β_range  = -.09 to -.11). Promoting strengths may secure a healthy start to life.

Mapping age- and sex-specific HIV prevalence in adults in sub-Saharan Africa, 2000-2018

BACKGROUND

Human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) is still among the leading causes of disease burden and mortality in sub-Saharan Africa (SSA), and the world is not on track to meet targets set for ending the epidemic by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the United Nations Sustainable Development Goals (SDGs). Precise HIV burden information is critical for effective geographic and epidemiological targeting of prevention and treatment interventions. Age- and sex-specific HIV prevalence estimates are widely available at the national level, and region-wide local estimates were recently published for adults overall. We add further dimensionality to previous analyses by estimating HIV prevalence at local scales, stratified into sex-specific 5-year age groups for adults ages 15-59 years across SSA.

METHODS

We analyzed data from 91 seroprevalence surveys and sentinel surveillance among antenatal care clinic (ANC) attendees using model-based geostatistical methods to produce estimates of HIV prevalence across 43 countries in SSA, from years 2000 to 2018, at a 5 × 5-km resolution and presented among second administrative level (typically districts or counties) units.

RESULTS

We found substantial variation in HIV prevalence across localities, ages, and sexes that have been masked in earlier analyses. Within-country variation in prevalence in 2018 was a median 3.5 times greater across ages and sexes, compared to for all adults combined. We note large within-district prevalence differences between age groups: for men, 50% of districts displayed at least a 14-fold difference between age groups with the highest and lowest prevalence, and at least a 9-fold difference for women. Prevalence trends also varied over time; between 2000 and 2018, 70% of all districts saw a reduction in prevalence greater than five percentage points in at least one sex and age group. Meanwhile, over 30% of all districts saw at least a five percentage point prevalence increase in one or more sex and age group.

CONCLUSIONS

As the HIV epidemic persists and evolves in SSA, geographic and demographic shifts in prevention and treatment efforts are necessary. These estimates offer epidemiologically informative detail to better guide more targeted interventions, vital for combating HIV in SSA.

Assessing performance of the Healthcare Access and Quality Index, overall and by select age groups, for 204 countries and territories, 1990-2019: a systematic analysis from the Global Burden of Disease Study 2019

BACKGROUND

Health-care needs change throughout the life course. It is thus crucial to assess whether health systems provide access to quality health care for all ages. Drawing from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 (GBD 2019), we measured the Healthcare Access and Quality (HAQ) Index overall and for select age groups in 204 locations from 1990 to 2019.

METHODS

We distinguished the overall HAQ Index (ages 0-74 years) from scores for select age groups: the young (ages 0-14 years), working (ages 15-64 years), and post-working (ages 65-74 years) groups. For GBD 2019, HAQ Index construction methods were updated to use the arithmetic mean of scaled mortality-to-incidence ratios (MIRs) and risk-standardised death rates (RSDRs) for 32 causes of death that should not occur in the presence of timely, quality health care. Across locations and years, MIRs and RSDRs were scaled from 0 (worst) to 100 (best) separately, putting the HAQ Index on a different relative scale for each age group. We estimated absolute convergence for each group on the basis of whether the HAQ Index grew faster in absolute terms between 1990 and 2019 in countries with lower 1990 HAQ Index scores than countries with higher 1990 HAQ Index scores and by Socio-demographic Index (SDI) quintile. SDI is a summary metric of overall development.

FINDINGS

Between 1990 and 2019, the HAQ Index increased overall (by 19·6 points, 95% uncertainty interval 17·9-21·3), as well as among the young (22·5, 19·9-24·7), working (17·2, 15·2-19·1), and post-working (15·1, 13·2-17·0) age groups. Large differences in HAQ Index scores were present across SDI levels in 2019, with the overall index ranging from 30·7 (28·6-33·0) on average in low-SDI countries to 83·4 (82·4-84·3) on average in high-SDI countries. Similarly large ranges between low-SDI and high-SDI countries, respectively, were estimated in the HAQ Index for the young (40·4-89·0), working (33·8-82·8), and post-working (30·4-79·1) groups. Absolute convergence in HAQ Index was estimated in the young group only. In contrast, divergence was estimated among the working and post-working groups, driven by slow progress in low-SDI countries.

INTERPRETATION

Although major gaps remain across levels of social and economic development, convergence in the young group is an encouraging sign of reduced disparities in health-care access and quality. However, divergence in the working and post-working groups indicates that health-care access and quality is lagging at lower levels of social and economic development. To meet the needs of ageing populations, health systems need to improve health-care access and quality for working-age adults and older populations while continuing to realise gains among the young.

FUNDING

Bill & Melinda Gates Foundation.

A population-based study of homelessness, antisocial behaviour and violence victimisation among young adults in Victoria, Australia

Homeless young adults are at increased risk for contact with the police and are overrepresented in the justice system. This study explored associations between homelessness, antisocial behaviour and violence victimisation using longitudinal panel data gathered through young adulthood. Data were drawn from a state representative population-based sample of young adults from Victoria, Australia participating in the International Youth Development Study (IYDS; n = 2884, 54% female). Participants were surveyed at age 21 years, with follow-up at ages 23 and 25 years. We examined changes in the prevalence of homelessness and tested hypothesised directional relationships between young adult homelessness, antisocial behaviour and violence victimisation using longitudinal cross-lagged panel models. Multiple-group modelling was used to test whether these relationships were moderated by gender. The prevalence of young adult homelessness was highest at age 21 (6.5%), declining at ages 23 (3.9%) and 25 years (2.5%). Results showed that young adult homelessness, antisocial behaviour and victimisation were related cross-sectionally, but not longitudinally. Gender did not significantly moderate these associations. Findings suggest that the state of homelessness is associated with temporary vulnerability to potentially harmful and problematic situations involving antisocial behaviour and victimisation. These situations are likely to heighten risk for contact with the police and direct physical and psychological harm.

The Cumulative Effect of Multilevel Factors on Myopia Prevalence, Incidence, and Progression Among Children and Adolescents in China During the COVID-19 Pandemic

Purpose

To estimate the effects of school closures and associated lifestyle changes on myopia in Chinese children and adolescents during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

Two cross-sectional surveys recruited 14,296 Chinese students aged 7 to 18 years in November 2019 and June 2020 from which an open cohort study (nested queue design) was derived and used to assess myopia prevalence, incidence, and progression rates (defined as students with progression in myopia severity at the second survey wave among those with myopia at baseline). The severity of myopia was determined by measurements of visual acuity (<5.0) and noncycloplegic refraction (spherical equivalent <-0.50 diopters). Twenty-three myopia-influencing factors were divided into three categories: eye-use habits, lifestyle, and family and subjective factors. Responses to each of these 23 factors were labeled as either positive or negative options and then combined to generate a comprehensive score.

Results

Boys and girls were equally represented (50%) and had the same average age (11.5 years) at each wave. The myopia prevalence increased from 48.2% to 60.0%, with 27.1% myopia incidence and 13.2% myopia progression rates for Chinese children and adolescents. Each of the 23 factors was associated with myopia prevalence but had no significant effect on myopia incidence or progression. However, these 23 factors had a cumulative effect on myopia risks; higher scores were associated with more positive factors and lower risk ratios of myopia and vice versa. Except for the progression rate, the myopia prevalence and incidence and risk ratios decreased with higher comprehensive scores.

Conclusions

School closures during the COVID-19 pandemic increased the risk of myopia in Chinese children and adolescents due to the accumulation of poor eyesight habits, unhealthy lifestyles, and excessive screen time.

Translational Relevance

Rather than focusing on single risk factors for myopia, future myopia prevention strategies should focus on integrating multiple comprehensive approaches across schools, families, and communities.

The role of school connectedness in the prevention of youth depression and anxiety: a systematic review with youth consultation

Background

School connectedness reflects the quality of students’ engagement with peers, teachers, and learning in the school environment. It has attracted attention from both the health and education sectors as a potentially modifiable protective factor for common mental health problems. However, the extent to which school connectedness may prevent the onset of youth depression or anxiety or promote their remission is unclear. This systematic review examined evidence for prospective relationships between school connectedness and depression and anxiety, and the effect of interventions to improve school connectedness on depression and anxiety.

Methods

We searched MEDLINE, PsycINFO, PubMed, and ERIC electronic databases for peer-reviewed quantitative longitudinal, or intervention studies published from 2011–21 in English examining relationships between school connectedness and anxiety and/or depression. Participants were 14–24 years old when depression and anxiety outcomes were assessed in any education setting in any country. We partnered with five youth advisers (aged 16–21 years) with lived experience of mental health problems and/or the schooling system in Australia, Indonesia, and the Philippines to ensure that youth perspectives informed the review.

Results

Our search identified 3552 unique records from which 34 longitudinal and 2 intervention studies were ultimately included. Studies were primarily from the United States of America (69.4%). Depression and anxiety outcomes were first measured at 14 years old, on average. Most studies found a significant protective relationship between higher levels of school connectedness and depressive and/or anxiety symptoms; more measured depression than anxiety. A few studies found a non-significant relationship. Both intervention studies designed to increase school connectedness improved depression, one through improvements in self-esteem and one through improvements in relationships at school.

Conclusions

These findings suggest that school connectedness may be a novel target for the prevention of depression and anxiety. We were not able to determine whether improving school connectedness promotes remission in young people already experiencing depression and anxiety. More studies examining anxiety, diagnostic outcomes, and beyond North America are warranted, as well as intervention trials.

Trial registration

PROSPERO 2021 CRD42021270967.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14364-6.

Learning outcomes in primary school children with emotional problems: a prospective cohort study

BACKGROUND

Academic difficulties are common in adolescents with mental health problems. Although earlier childhood emotional problems, characterised by heightened anxiety and depressive symptoms are common forerunners to adolescent mental health problems, the degree to which mental health problems in childhood may contribute independently to academic difficulties has been little explored.

METHODS

Data were drawn from a prospective cohort study of students in Melbourne, Australia (N = 1239). Data were linked with a standardised national assessment of academic performance at baseline (9 years) and wave three (11 years). Depressive and anxiety symptoms were assessed at baseline and wave two (10 years). Regression analyses estimated the association between emotional problems (9 and/or 10 years) and academic performance at 11 years, adjusting for baseline academic performance, sex, age and socioeconomic status, and hyperactivity/inattention symptoms.

RESULTS

Students with depressive symptoms at 9 years of age had lost nearly 4 months of numeracy learning two years later after controlling for baseline academic performance and confounders. Results were similar for anxiety symptoms. Regardless of when depressive symptoms occurred there were consistent associations with poorer numeracy performance at 11 years. The association of depressive symptoms with reading performance was weaker than for numeracy if they were present at wave two. Persistent anxiety symptoms across two waves led to nearly a 4 month loss of numeracy learning at 11 years, but the difference was not meaningful for reading. Findings were similar when including hyperactivity/inattention symptoms.

CONCLUSIONS

Childhood anxiety and depression are not only forerunners of later mental health problems but predict academic achievement. Partnerships between education and health systems have the potential to not only improve childhood emotional problems but also improve learning.

Towards standardised and valid anthropometric indicators of nutritional status in middle childhood and adolescence

Recognition of the importance of nutrition during middle childhood (age 5-9 years) and adolescence (age 10-19 years) is increasing, particularly in the context of global food insecurity and rising overweight and obesity rates. Until now, policy makers have been slow to respond to rapidly changing patterns of malnutrition across these age groups. One barrier has been a scarcity of consistent and regular nutrition surveillance systems for these age groups. What should be measured, and how best to operationalise anthropometric indicators that have been the cornerstone of nutrition surveillance in younger children and in adults, has been the topic of ongoing debate. Even with consensus on the importance of a given anthropometric indicator, difficulties arise in interpreting trends over time and between countries owing to the use of different terminologies, reference data, and cutoff points. In this Viewpoint we highlight the need to revisit anthropometric indicators across middle childhood and adolescence, a process that will require WHO and UNICEF coordination, the engagement of national implementors and policy makers, and partnership with research communities and donors.

The Australian Temperament Project Generation 3 study: a population-based multigenerational prospective cohort study of socioemotional health and development

PURPOSE

The Australian Temperament Project Generation 3 Study (ATPG3) was established to examine the extent to which offspring social and emotional development is shaped in the decades prior to conception, in parent and grandparent histories of psychosocial adjustment (eg, emotional regulation, relationship quality and prosociality) and maladjustment (eg, depressive symptoms, substance use and antisociality).

PARTICIPANTS

The Australian Temperament Project (ATP) commenced in 1983 as a population representative survey of the social and emotional health of 2443 young Australians (Generation 2: 4-8 months old) and their parents (Generation 1). Since then, families have been followed from infancy to young adulthood (16 waves). Between 2012 and 2018, the cohort was screened biannually for pregnancies (Generation 3), with assessments conducted in the third trimester of pregnancy, and at 8 weeks and 1 year postpartum.

FINDINGS TO DATE

A total of 1167 offspring (607 female) born to 703 Generation 2 parents (400 mothers) were recruited into the ATPG3 Study. Findings to date highlight: (1) strong continuities in depressive symptoms and substance use from adolescence through to becoming a parent; (2) a role for persistent preconception mental health problems in risk for parent-child bonding difficulties, as well as infant emotional reactivity and behaviour problems; (3) the importance of secure attachments in adolescence in reducing long-term risk for postpartum mental health problems; and (4) the protective nature of perceived social support, both preconception and postpartum, in strengthening relationship quality and social support during the COVID-19 pandemic.

FUTURE PLANS

Assessments of ATPG3 families in preschool and middle childhood are currently funded and underway. We intend to maintain the offspring cohort through childhood, adolescence, young adulthood and into parenthood. Data will be used to map preconception determinants of emotional health, and enhance approaches to population monitoring and targeted intervention over the life course and across generations.

Impact of early intervention on the population prevalence of common mental disorders: 20-year prospective study

BACKGROUND

The potential for early interventions to reduce the later prevalence of common mental disorders (CMD) first experienced in adolescence is unclear.

AIMS

To examine the course of CMD and evaluate the extent to which the prevalence of CMD could be reduced by preventing adolescent CMD, or by intervening to change four young adult processes, between the ages of 20 and 29 years, that could be mediating the link between adolescent and adult disorder.

METHOD

This was a prospective cohort study of 1923 Australian participants assessed repeatedly from adolescence (wave 1, mean age 14 years) to adulthood (wave 10, mean age 35 years). Causal mediation analysis was undertaken to evaluate the extent to which the prevalence of CMD at age 35 years in those with adolescent CMD could be reduced by either preventing adolescent CMD, or by intervening on four young adult mediating processes: the occurrence of young adult CMD, frequent cannabis use, parenting a child by age 24 years, and engagement in higher education and employment.

RESULTS

At age 35, 19.2% of participants reported CMD; a quarter of these participants experienced CMD during both adolescence and young adulthood. In total, 49% of those with CMD during both adolescence and young adulthood went on to report CMD at age 35 years. Preventing adolescent CMD reduced the population prevalence at age 35 years by 3.9%. Intervening on all four young adult processes among those with adolescent CMD, reduced this prevalence by 1.6%.

CONCLUSIONS

In this Australian cohort, a large proportion of adolescent CMD resolved by adulthood, and by age 35 years, the largest proportion of CMD emerged among individuals without prior CMD. Time-limited, early intervention in those with earlier adolescent disorder is unlikely to substantially reduce the prevalence of CMD in midlife.

Population-level risks of alcohol consumption by amount, geography, age, sex, and year: a systematic analysis for the Global Burden of Disease Study 2020

BACKGROUND

The health risks associated with moderate alcohol consumption continue to be debated. Small amounts of alcohol might lower the risk of some health outcomes but increase the risk of others, suggesting that the overall risk depends, in part, on background disease rates, which vary by region, age, sex, and year.

METHODS

For this analysis, we constructed burden-weighted dose-response relative risk curves across 22 health outcomes to estimate the theoretical minimum risk exposure level (TMREL) and non-drinker equivalence (NDE), the consumption level at which the health risk is equivalent to that of a non-drinker, using disease rates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020 for 21 regions, including 204 countries and territories, by 5-year age group, sex, and year for individuals aged 15-95 years and older from 1990 to 2020. Based on the NDE, we quantified the population consuming harmful amounts of alcohol.

FINDINGS

The burden-weighted relative risk curves for alcohol use varied by region and age. Among individuals aged 15-39 years in 2020, the TMREL varied between 0 (95% uncertainty interval 0-0) and 0·603 (0·400-1·00) standard drinks per day, and the NDE varied between 0·002 (0-0) and 1·75 (0·698-4·30) standard drinks per day. Among individuals aged 40 years and older, the burden-weighted relative risk curve was J-shaped for all regions, with a 2020 TMREL that ranged from 0·114 (0-0·403) to 1·87 (0·500-3·30) standard drinks per day and an NDE that ranged between 0·193 (0-0·900) and 6·94 (3·40-8·30) standard drinks per day. Among individuals consuming harmful amounts of alcohol in 2020, 59·1% (54·3-65·4) were aged 15-39 years and 76·9% (73·0-81·3) were male.

INTERPRETATION

There is strong evidence to support recommendations on alcohol consumption varying by age and location. Stronger interventions, particularly those tailored towards younger individuals, are needed to reduce the substantial global health loss attributable to alcohol.

FUNDING

Bill & Melinda Gates Foundation.

World Health Organization and knowledge translation in maternal, newborn, child and adolescent health and nutrition

The World Health Organization (WHO) has a mandate to promote maternal and child health and welfare through support to governments in the form of technical assistance, standards, epidemiological and statistical services, promoting teaching and training of healthcare professionals and providing direct aid in emergencies. The Strategic and Technical Advisory Group of Experts (STAGE) for maternal, newborn, child and adolescent health and nutrition (MNCAHN) was established in 2020 to advise the Director-General of WHO on issues relating to MNCAHN. STAGE comprises individuals from multiple low-income and middle-income and high-income countries, has representatives from many professional disciplines and with diverse experience and interests.Progress in MNCAHN requires improvements in quality of services, equity of access and the evolution of services as technical guidance, community needs and epidemiology changes. Knowledge translation of WHO guidance and other guidelines is an important part of this. Countries need effective and responsive structures for adaptation and implementation of evidence-based interventions, strategies to improve guideline uptake, education and training and mechanisms to monitor quality and safety. This paper summarises STAGE's recommendations on how to improve knowledge translation in MNCAHN. They include support for national and regional technical advisory groups and subnational committees that coordinate maternal and child health; support for national plans for MNCAHN and their implementation and monitoring; the production of a small number of consolidated MNCAHN guidelines to promote integrated and holistic care; education and quality improvement strategies to support guidelines uptake; monitoring of gaps in knowledge translation and operational research in MNCAHN.

What can work and how? An overview of evidence-based interventions and delivery strategies to support health and human development from before conception to 20 years

Progress has been made globally in improving the coverage of key maternal, newborn, and early childhood interventions in low-income and middle-income countries, which has contributed to a decrease in child mortality and morbidity. However, inequities remain, and many children and adolescents are still not covered by life-saving and nurturing care interventions, despite their relatively low costs and high cost-effectiveness. This Series paper builds on a large body of work from the past two decades on evidence-based interventions and packages of care for survival, strategies for delivery, and platforms to reach the most vulnerable. We review the current evidence base on the effectiveness of a variety of essential and emerging interventions that can be delivered from before conception until age 20 years to help children and adolescents not only survive into adulthood, but also to grow and develop optimally, support their wellbeing, and help them reach their full developmental potential. Although scaling up evidence-based interventions in children younger than 5 years might have the greatest effect on reducing child mortality rates, we highlight interventions and evidence gaps for school-age children (5-9 years) and the transition from childhood to adolescence (10-19 years), including interventions to support mental health and positive development, and address unintentional injuries, neglected tropical diseases, and non-communicable diseases.

Health and development from preconception to 20 years of age and human capital

Optimal health and development from preconception to adulthood are crucial for human flourishing and the formation of human capital. The Nurturing Care Framework, as adapted to age 20 years, conceptualises the major influences during periods of development from preconception, through pregnancy, childhood, and adolescence that affect human capital. In addition to mortality in children younger than 5 years, stillbirths and deaths in 5-19-year-olds are important to consider. The global rate of mortality in individuals younger than 20 years has declined substantially since 2000, yet in 2019 an estimated 8·6 million deaths occurred between 28 weeks of gestation and 20 years of age, with more than half of deaths, including stillbirths, occurring before 28 days of age. The 1000 days from conception to 2 years of age are especially influential for human capital. The prevalence of low birthweight is high in sub-Saharan Africa and even higher in south Asia. Growth faltering, especially from birth to 2 years, occurs in most world regions, whereas overweight increases in many regions from the preprimary school period through adolescence. Analyses of cohort data show that growth trajectories in early years of life are strong determinants of nutritional outcomes in adulthood. The accrual of knowledge and skills is affected by health, nutrition, and home resources in early childhood and by educational opportunities in older children and adolescents. Linear growth in the first 2 years of life better predicts intelligence quotients in adults than increases in height in older children and adolescents. Learning-adjusted years of schooling range from about 4 years in sub-Saharan Africa to about 11 years in high-income countries. Human capital depends on children and adolescents surviving, thriving, and learning until adulthood.

Health, social and economic implications of adolescent risk behaviours/states: protocol for Raine Study Gen2 cohort data linkage study

BACKGROUND

Risk-taking behaviours are a major contributor to youth morbidity and mortality. Vulnerability to these negative outcomes is constructed from individual behaviour including risk-taking, and from social context, ecological determinants, early life experience, developmental capacity and mental health, contributing to a state of higher risk. However, although risk-taking is part of normal adolescent development, there is no systematic way to distinguish young people with a high probability of serious adverse outcomes, hindering the capacity to screen and intervene. This study aims to explore the association between risk behaviours/states in adolescence and negative health, social and economic outcomes through young adulthood.

METHODS

The Raine Study is a prospective cohort study which recruited pregnant women in 1989-91, in Perth, Western Australia. The offspring cohort (N = 2,868) was followed up at regular intervals from 1 to 27 years of age. These data will be linked to State government health and welfare administrative data. We will empirically examine relationships across multiple domains of risk (for example, substance use, sexual behaviour, driving) with health and social outcomes (for instance, road-crash injury, educational underachievement). Microsimulation models will measure the impact of risk-taking on educational attainment and labour force outcomes.

DISCUSSION

Comprehensive preventive child health programmes and policy prioritise a healthy start to life. This is the first linkage study focusing on adolescence to adopt a multi-domain approach, and to integrate health economic modelling. This approach captures a more complete picture of health and social impacts of risk behaviour/​states in adolescence and young adulthood.

Longitudinal prediction of periconception alcohol use: a 20-year prospective cohort study across adolescence, young adulthood and pregnancy

BACKGROUND AND AIMS

Alcohol consumption is common in adolescence and young adulthood and may continue into pregnancy, posing serious risk to early fetal development. We examine the frequency of periconception alcohol use (prior to pregnancy awareness) and the extent to which adolescent and young adult alcohol use prospectively predict periconception use.

DESIGN

A longitudinal, population-based study.

SETTING

Victoria, Australia.

PARTICIPANTS

A total of 289 women in trimester three of pregnancy (age 29-35 years; 388 pregnancies).

MEASURES

The main exposures were binge [≥ 4.0 standard drinks (SDs)/day] and frequent (≥ 3 days/week) drinking in adolescence (mean age = 14.9-17.4 years) and young adulthood (mean age 20.7-29.1 years). Outcomes were frequency (≥ 3 days/week, ≥ monthly, never) and quantity (≥ 4.0 SDs, ≥ 0.5 and < 4.0 SDs, none) of periconception drinking.

FINDINGS

Alcohol use was common in young adulthood prior to pregnancy (72%) and in the early weeks of pregnancy (76%). The proportions drinking on most days and binge drinking were similar at both points. Reflecting a high degree of continuity in alcohol use behaviours, most women who drank periconceptionally had an earlier history of frequent (77%) and/or binge (85%) drinking throughout the adolescent or young adult years. Young adult binge drinking prospectively predicted periconception drinking quantity [odds ratio (OR) = 3.7, 95% confidence interval (CI) = 1.9-7.4], compared with women with no prior history. Similarly, frequent young adult drinking prospectively predicted frequent periconception drinking (OR = 30.7, 95% CI = 12.3-76.7).

CONCLUSIONS

Women who engage in risky (i.e. frequent and binge) drinking in their adolescent and young adult years are more likely to report risky drinking in early pregnancy prior to pregnancy recognition than women with no prior history of risky drinking.

Nutrition in adolescent growth and development

During adolescence, growth and development are transformative and have profound consequences on an individual's health in later life, as well as the health of any potential children. The current generation of adolescents is growing up at a time of unprecedented change in food environments, whereby nutritional problems of micronutrient deficiency and food insecurity persist, and overweight and obesity are burgeoning. In a context of pervasive policy neglect, research on nutrition during adolescence specifically has been underinvested, compared with such research in other age groups, which has inhibited the development of adolescent-responsive nutritional policies. One consequence has been the absence of an integrated perspective on adolescent growth and development, and the role that nutrition plays. Through late childhood and early adolescence, nutrition has a formative role in the timing and pattern of puberty, with consequences for adult height, muscle, and fat mass accrual, as well as risk of non-communicable diseases in later life. Nutritional effects in adolescent development extend beyond musculoskeletal growth, to cardiorespiratory fitness, neurodevelopment, and immunity. High rates of early adolescent pregnancy in many countries continue to jeopardise the growth and nutrition of female adolescents, with consequences that extend to the next generation. Adolescence is a nutrition-sensitive phase for growth, in which the benefits of good nutrition extend to many other physiological systems.

Strategies and interventions for healthy adolescent growth, nutrition, and development

Adolescence is a pivotal point in the life course, characterised by transformative physical, cognitive, and emotional growth, an openness to change, and a drive to reshape the social environment. It offers unique opportunities to adopt changes in diet and physical activity that can persist into later life. Yet pre-existing nutritional problems, including micronutrient deficiencies, food insecurity, and poor-quality diets, persist at the same time as adolescents face the rapid emergence of an obesity epidemic. Adolescent growth and nutrition has been largely overlooked in intervention and policy research. Most intervention studies have emphasised micronutrient supplementation, with few taking into account the multiple drivers of adolescent diets. This Series paper highlights that effective interventions and policies will need to cut across sectors; be supported by multifaceted and multilevel policy; and extend across education, health, food systems, social protection, and digital media. Better data standardisation and systems will be essential in coordinating and monitoring these responses. In a context of shifts in planetary ecosystems and commercial drivers, resilient food systems will need to both ensure access to healthy and affordable foods and provide the infrastructure and incentives for continuing physical activity. Intergenerational partnerships with young people will be essential in bringing about transformative change and ensuring that food policies reflect their needs and aspirations.

Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial

IMPORTANCE

A rapid nutritional transition has caused greater childhood obesity prevalence in many countries, but the repertoire of effective preventive interventions remains limited.

OBJECTIVE

To determine the effectiveness of a novel multifaceted intervention for obesity prevention in primary school children.

DESIGN, SETTING, AND PARTICIPANTS

A cluster randomized clinical trial was conducted during a single school year (from September 11, 2018, to June 30, 2019) across 3 socioeconomically distinct regions in China according to a prespecified trial protocol. Twenty-four schools were randomly allocated (1:1) to the intervention or the control group, with 1392 eligible children aged 8 to 10 years participating. Data from the intent-to-treat population were analyzed from October 1 to December 31, 2019.

INTERVENTIONS

A multifaceted intervention targeted both children (promoting healthy diet and physical activity) and their environment (engaging schools and families to support children's behavioral changes). The intervention was novel in its strengthening of family involvement with the assistance of a smartphone app. The control schools engaged in their usual practices.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in body mass index (BMI; calculated as weight in kilograms divided by height in square meters) from baseline to the end of the trial. Secondary outcomes included changes in adiposity outcomes (eg, BMI z score, prevalence of obesity), blood pressure, physical activity and dietary behaviors, obesity-related knowledge, and physical fitness. Generalized linear mixed models were used in the analyses.

RESULTS

Among the 1392 participants (mean [SD] age, 9.6 [0.4] years; 717 boys [51.5%]; mean [SD] BMI, 18.6 [3.7]), 1362 (97.8%) with follow-up data were included in the analyses. From baseline to the end of the trial, the mean BMI decreased in the intervention group, whereas it increased in the control group; the mean between-group difference in BMI change was -0.46 (95% CI, -0.67 to -0.25; P < .001), which showed no evidence of difference across different regions, sexes, maternal education levels, and primary caregivers (parents vs nonparents). The prevalence of obesity decreased by 27.0% of the baseline figure (a relative decrease) in the intervention group, compared with 5.6% in the control group. The intervention also improved other adiposity outcomes, dietary, sedentary, and physical activity behaviors, and obesity-related knowledge, but it did not change moderate- to vigorous-intensity physical activity, physical fitness, or blood pressure. No adverse events were observed during the intervention.

CONCLUSIONS AND RELEVANCE

The multifaceted intervention effectively reduced the mean BMI and obesity prevalence in primary school children across socioeconomically distinct regions in China, suggesting its potential for national scaling.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03665857.

Coverage of school health monitoring systems in China: a large national cross-sectional survey

Background

There is growing interest in the role that schools can play in promoting student health. The aim of this study was to describe the coverage of school health monitoring systems for infectious diseases, non-communicable diseases, and school physical environments in China, and to explore differences by geography, regional wealth, and school type.

Methods

A cross-sectional study was performed using data from 2428 schools from 17 provinces in China in 2018. Data were collected using a questionnaire administered by the Ministry of Education through its monitoring system, and included infectious diseases (e.g., reporting system for student infectious diseases), non-communicable diseases (e.g., regular student health examinations), and school physical environments (e.g., monitoring of classroom light, microclimate and drinking water).

Findings

Overall, the coverage rate of full school health monitoring systems was 16·6%. The coverage rates of school health monitoring systems for infectious diseases, non-communicable diseases, and school physical environments were 71·2%, 68·5%, and 24·9%, respectively. Coverage was higher in schools from urban rather than rural areas, in schools from areas with greater wealth, and in senior secondary schools rather than junior secondary and primary schools.

Interpretation

Systems for monitoring infectious diseases in school students have been widely implemented in China. Systems for monitoring non-communicable diseases and physical environments need to be strengthened. Beyond greater attention in poorer and rural areas, increased investment in more comprehensive approaches to school health is indicated.

Funding

This study was supported by National Statistical Science Research Project (2021LY052 to YS) and China Scholarship Council (201906015028 to PH).

Global, regional, and national time trends in mortality for congenital heart disease, 1990-2019: An age-period-cohort analysis for the Global Burden of Disease 2019 study

BACKGROUND

Congenital heart disease (CHD) is the leading cause of morbidity and mortality from birth defects worldwide. We report an overview of trends in CHD mortality in 204 countries and territories over the past 30 years and associations with age, period, and birth cohort.

METHODS

Cause-specific CHD mortality estimates were derived from the Global Burden of Disease 2019 study. We utilised an age-period-cohort model to estimate overall annual percentage changes in mortality (net drifts), annual percentage changes from 0 to 4 to 65-69 years (local drifts), period and cohort relative risks (period/cohort effects) between 1990 and 2019. This approach allows for the examination and differentiation of age, period, and cohort effects in the mortality trends, with the potential to identify disparities and treatment gaps in cardiac care.

FINDINGS

CHD is the leading cause of deaths from non-communicable diseases (NCDs) in those under 20 years. Global CHD deaths in 2019 were 217,000 (95% uncertainty interval 177,000-262,000). There were 129 countries with at least 50 deaths. India, China, Pakistan, and Nigeria had the highest mortality, accounting for 39.7% of deaths globally. Between 1990 and 2019, the net drift of CHD mortality ranged from -2.41% per year (95% confidence interval [CI] -2.55, -2.67) in high Socio-demographic Index (SDI) countries to -0.62% per year (95% CI: -0.82, -0.42) in low-SDI countries. Globally, there was an emerging transition in the age distribution of deaths from paediatric to adult populations, except for an increasing trend of mortality in those aged 10-34 years in Mexico and Pakistan. During the past 30 years, favourable mortality reductions were generally found in most high-SDI countries like South Korea (net drift = -4.0% [95% CI -4.8 to -3.1] per year) and the United States (-2.3% [-2.5 to -2.0]), and also in many middle-SDI countries like Brazil (-2.7% [-3.1 to 2.4]) and South Africa (-2.5% [-3.2 to -1.8]). However, 52 of 129 countries had either increasing trends (net drifts ≥0.0%) or stagnated reductions (≥-0.5%) in mortality. The relative risk of mortality generally showed improving trends over time and in successively younger birth cohorts amongst high- and high-middle-SDI countries, with the exceptions of Saudi Arabia and Kazakhstan. 14 middle-SDI countries such as Ecuador and Mexico, and 16 low-middle-SDI countries including India and 20 low-SDI countries including Pakistan, had unfavourable or worsening risks for recent periods and birth cohorts.

INTERPRETATION

CHD mortality is a useful and accessible indicator of trends in the provision of congenital cardiac care both in early childhood and across later life. Improvements in the treatment of CHD should reduce the risk for successively younger cohorts and shift the risk for all age groups over time. Although there were gains in CHD mortality globally over the past three decades, unfavourable period and cohort effects were found in many countries, raising questions about adequacy of their health care for CHD patients across all age groups. These failings carry significant implications for the likelihood of achieving the Sustainable Development Goal targets for under-5 years and NCD mortality.

FUNDING

Supported by the National Natural Science Foundation of China (81525002, 31971048, 82073573 to ZZ and HZ), Shanghai Outstanding Medical Academic Leader program (2019LJ22 to HZ), and Collaborative Innovation Program of Shanghai Municipal Health Commission (2020CXJQ01 to HZ), the Bill & Melinda Gates Foundation for the Global Burden of Disease Project (to NJK) and NHMRC fellowship administered through the University of Melbourne (to GCP).

Global, regional, and national mortality among young people aged 10-24 years, 1950-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Documentation of patterns and long-term trends in mortality in young people, which reflect huge changes in demographic and social determinants of adolescent health, enables identification of global investment priorities for this age group. We aimed to analyse data on the number of deaths, years of life lost, and mortality rates by sex and age group in people aged 10-24 years in 204 countries and territories from 1950 to 2019 by use of estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.

METHODS

We report trends in estimated total numbers of deaths and mortality rate per 100 000 population in young people aged 10-24 years by age group (10-14 years, 15-19 years, and 20-24 years) and sex in 204 countries and territories between 1950 and 2019 for all causes, and between 1980 and 2019 by cause of death. We analyse variation in outcomes by region, age group, and sex, and compare annual rate of change in mortality in young people aged 10-24 years with that in children aged 0-9 years from 1990 to 2019. We then analyse the association between mortality in people aged 10-24 years and socioeconomic development using the GBD Socio-demographic Index (SDI), a composite measure based on average national educational attainment in people older than 15 years, total fertility rate in people younger than 25 years, and income per capita. We assess the association between SDI and all-cause mortality in 2019, and analyse the ratio of observed to expected mortality by SDI using the most recent available data release (2017).

FINDINGS

In 2019 there were 1·49 million deaths (95% uncertainty interval 1·39-1·59) worldwide in people aged 10-24 years, of which 61% occurred in males. 32·7% of all adolescent deaths were due to transport injuries, unintentional injuries, or interpersonal violence and conflict; 32·1% were due to communicable, nutritional, or maternal causes; 27·0% were due to non-communicable diseases; and 8·2% were due to self-harm. Since 1950, deaths in this age group decreased by 30·0% in females and 15·3% in males, and sex-based differences in mortality rate have widened in most regions of the world. Geographical variation has also increased, particularly in people aged 10-14 years. Since 1980, communicable and maternal causes of death have decreased sharply as a proportion of total deaths in most GBD super-regions, but remain some of the most common causes in sub-Saharan Africa and south Asia, where more than half of all adolescent deaths occur. Annual percentage decrease in all-cause mortality rate since 1990 in adolescents aged 15-19 years was 1·3% in males and 1·6% in females, almost half that of males aged 1-4 years (2·4%), and around a third less than in females aged 1-4 years (2·5%). The proportion of global deaths in people aged 0-24 years that occurred in people aged 10-24 years more than doubled between 1950 and 2019, from 9·5% to 21·6%.

INTERPRETATION

Variation in adolescent mortality between countries and by sex is widening, driven by poor progress in reducing deaths in males and older adolescents. Improving global adolescent mortality will require action to address the specific vulnerabilities of this age group, which are being overlooked. Furthermore, indirect effects of the COVID-19 pandemic are likely to jeopardise efforts to improve health outcomes including mortality in young people aged 10-24 years. There is an urgent need to respond to the changing global burden of adolescent mortality, address inequities where they occur, and improve the availability and quality of primary mortality data in this age group.

FUNDING

Bill & Melinda Gates Foundation.

Growth and adrenarche: findings from the CATS observational study

BACKGROUND

There is increasing evidence that patterns of pubertal maturation are associated with different patterns of health risk. This study aimed to explore the associations between anthropometric measures and salivary androgen concentrations in pre-adolescent children.

METHODS

We analysed a stratified random sample (N=1151) of pupils aged 8-9 years old from 43 primary schools in Melbourne, Australia from the Childhood to Adolescence Transition Study. Saliva samples were assayed for dehydroepiandrosterone (DHEA), DHEA-sulfate and testosterone. Anthropometric measures included height, weight, body mass index (BMI) and waist circumference. Associations between (1) anthropometric measures and each androgen, and (2) hormone status with obesity and parental report of pubertal development were investigated using linear regression modelling with general estimating equations.

RESULTS

Greater height, weight, BMI and waist circumference were positively associated with higher androgen concentrations, after adjusting for sex and socioeconomic status. Being overweight or obese was associated with higher testosterone and DHEA concentrations compared with the normal BMI category. Those who were obese were more likely (OR=2.7, 95% CI 1.61 to 4.43, p<0.001) to be in the top tertile of age-adjusted androgen status in both sexes.

CONCLUSION

This study provides clear evidence for an association between obesity and higher androgen levels in mid-childhood. The adrenal transition may be a critical time period for weight management intervention strategies in order to manage the risk for metabolic problems in later life for high-risk individuals.

Global, regional, and national progress towards Sustainable Development Goal 3.2 for neonatal and child health: all-cause and cause-specific mortality findings from the Global Burden of Disease Study 2019

BACKGROUND

Sustainable Development Goal 3.2 has targeted elimination of preventable child mortality, reduction of neonatal death to less than 12 per 1000 livebirths, and reduction of death of children younger than 5 years to less than 25 per 1000 livebirths, for each country by 2030. To understand current rates, recent trends, and potential trajectories of child mortality for the next decade, we present the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 findings for all-cause mortality and cause-specific mortality in children younger than 5 years of age, with multiple scenarios for child mortality in 2030 that include the consideration of potential effects of COVID-19, and a novel framework for quantifying optimal child survival.

METHODS

We completed all-cause mortality and cause-specific mortality analyses from 204 countries and territories for detailed age groups separately, with aggregated mortality probabilities per 1000 livebirths computed for neonatal mortality rate (NMR) and under-5 mortality rate (U5MR). Scenarios for 2030 represent different potential trajectories, notably including potential effects of the COVID-19 pandemic and the potential impact of improvements preferentially targeting neonatal survival. Optimal child survival metrics were developed by age, sex, and cause of death across all GBD location-years. The first metric is a global optimum and is based on the lowest observed mortality, and the second is a survival potential frontier that is based on stochastic frontier analysis of observed mortality and Healthcare Access and Quality Index.

FINDINGS

Global U5MR decreased from 71·2 deaths per 1000 livebirths (95% uncertainty interval [UI] 68·3-74·0) in 2000 to 37·1 (33·2-41·7) in 2019 while global NMR correspondingly declined more slowly from 28·0 deaths per 1000 live births (26·8-29·5) in 2000 to 17·9 (16·3-19·8) in 2019. In 2019, 136 (67%) of 204 countries had a U5MR at or below the SDG 3.2 threshold and 133 (65%) had an NMR at or below the SDG 3.2 threshold, and the reference scenario suggests that by 2030, 154 (75%) of all countries could meet the U5MR targets, and 139 (68%) could meet the NMR targets. Deaths of children younger than 5 years totalled 9·65 million (95% UI 9·05-10·30) in 2000 and 5·05 million (4·27-6·02) in 2019, with the neonatal fraction of these deaths increasing from 39% (3·76 million [95% UI 3·53-4·02]) in 2000 to 48% (2·42 million; 2·06-2·86) in 2019. NMR and U5MR were generally higher in males than in females, although there was no statistically significant difference at the global level. Neonatal disorders remained the leading cause of death in children younger than 5 years in 2019, followed by lower respiratory infections, diarrhoeal diseases, congenital birth defects, and malaria. The global optimum analysis suggests NMR could be reduced to as low as 0·80 (95% UI 0·71-0·86) deaths per 1000 livebirths and U5MR to 1·44 (95% UI 1·27-1·58) deaths per 1000 livebirths, and in 2019, there were as many as 1·87 million (95% UI 1·35-2·58; 37% [95% UI 32-43]) of 5·05 million more deaths of children younger than 5 years than the survival potential frontier.

INTERPRETATION

Global child mortality declined by almost half between 2000 and 2019, but progress remains slower in neonates and 65 (32%) of 204 countries, mostly in sub-Saharan Africa and south Asia, are not on track to meet either SDG 3.2 target by 2030. Focused improvements in perinatal and newborn care, continued and expanded delivery of essential interventions such as vaccination and infection prevention, an enhanced focus on equity, continued focus on poverty reduction and education, and investment in strengthening health systems across the development spectrum have the potential to substantially improve U5MR. Given the widespread effects of COVID-19, considerable effort will be required to maintain and accelerate progress.

FUNDING

Bill & Melinda Gates Foundation.

Adolescent antecedents of maternal and paternal perinatal depression: a 36-year prospective cohort

BACKGROUND

Rates of common mental health problems (depression/anxiety) rise sharply in adolescence and peak in young adulthood, often coinciding with the transition to parenthood. Little is known regarding the persistence of common mental health problems from adolescence to the perinatal period in both mothers and fathers.

METHODS

A total of 393 mothers (686 pregnancies) and 257 fathers (357 pregnancies) from the intergenerational Australian Temperament Project Generation 3 Study completed self-report assessments of depression and anxiety in adolescence (ages 13-14, 15-16, 17-18 years) and young adulthood (ages 19-20, 23-24, 27-28 years). The Edinburgh Postnatal Depression Scale was used to assess depressive symptoms at 32 weeks pregnancy and 12 months postpartum in mothers, and at 12 months postpartum in fathers.

RESULTS

Most pregnancies (81%) in which mothers reported perinatal depression were preceded by a history of mental health problems in adolescence or young adulthood. Similarly, most pregnancies (83%) in which fathers reported postnatal depression were preceded by a preconception history of mental health problems. After adjustment for potential confounders, the odds of self-reporting perinatal depression in both women and men were consistently higher in those with a history of persistent mental health problems across adolescence and young adulthood than those without (OR_women 5.7, 95% CI 2.9-10.9; OR_men 5.5, 95% CI 1.03-29.70).

CONCLUSIONS

Perinatal depression, for the majority of parents, is a continuation of mental health problems with onsets well before pregnancy. Strategies to promote good perinatal mental health should start before parenthood and include both men and women.

Life-course predictors of homelessness from adolescence into adulthood: A population-based cohort study

INTRODUCTION

Internationally, the prevalence of young adult homelessness is concerning. Few data on life-course predictors from longitudinal studies exist, limiting our capacity to inform prevention strategies at the population-level.

METHODS

Data were drawn from a state representative population-based sample of young adults from Victoria, Australia participating in the International Youth Development Study (IYDS; N = 927, 54% female). Participants were recruited in state-representative secondary school samples at Grade 7 (age 13, 2002), with follow-up in Grades 9 (age 15) and 11 (age 17) and at ages 21, 23 and 25. Using longitudinal path modelling, we conducted a series of analyses testing life-course predictors of young adult homelessness across multiple socializing contexts, and the interrelationships among them.

RESULTS

The rate of young adult homelessness was 5.5%. Path modelling showed higher levels of family conflict at ages 13 and 15 uniquely predicted homelessness by age 25. This effect remained after accounting for other risk factors in peer-group (e.g., interactions with antisocial peers), school (e.g., low academic performance), and community contexts (e.g., low neighborhood attachment). Peer drug use and interaction with antisocial peers at age 15 mediated the association between family conflict at age 13 and homelessness by age 25.

CONCLUSIONS

Findings point to the vulnerability of early adolescents to family conflict. This vulnerability heightens risk for young adult homelessness. Findings strengthen the case for both primary prevention programs that build healthy relationships between family members from early on in adolescence and for investment in homelessness prevention at key developmental periods.

Preventing postnatal depression: a causal mediation analysis of a 20-year preconception cohort

Postnatal depression (PND) is common and predicts a range of adverse maternal and offspring outcomes. PND rates are highest among women with persistent mental health problems before pregnancy, and antenatal healthcare provides ideal opportunity to intervene. We examined antenatal perceived social support as a potential intervention target in preventing PND symptoms among women with prior mental health problems. A total of 398 Australian women (600 pregnancies) were assessed repeatedly for mental health problems before pregnancy (ages 14-29 years, 1992-2006), and again during pregnancy, two months postpartum and one year postpartum (2006-2014). Causal mediation analysis found that intervention on perceived antenatal social support has the potential to reduce rates of PND symptoms by up to 3% (from 15 to 12%) in women with persistent preconception symptoms. Supplementary analyses found that the role of low antenatal social support was independent of concurrent antenatal depressive symptoms. Combined, these two factors mediated up to more than half of the association between preconception mental health problems and PND symptoms. Trialling dual interventions on antenatal depressive symptoms and perceived social support represents one promising strategy to prevent PND in women with persistent preconception symptoms. Interventions promoting mental health before pregnancy may yield an even greater reduction in PND symptoms by disrupting a developmental cascade of risks via these and other pathways. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.

Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990-2019: a systematic analysis from the Global Burden of Disease Study 2019

BACKGROUND

Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally.

METHODS

We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available.

FINDINGS

Globally in 2019, 1·14 billion (95% uncertainty interval 1·13-1·16) individuals were current smokers, who consumed 7·41 trillion (7·11-7·74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27·5% [26·5-28·5] reduction) and females (37·7% [35·4-39·9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0·99 billion (0·98-1·00) in 1990. Globally in 2019, smoking tobacco use accounted for 7·69 million (7·16-8·20) deaths and 200 million (185-214) disability-adjusted life-years, and was the leading risk factor for death among males (20·2% [19·3-21·1] of male deaths). 6·68 million [86·9%] of 7·69 million deaths attributable to smoking tobacco use were among current smokers.

INTERPRETATION

In the absence of intervention, the annual toll of 7·69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a clear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens.

FUNDING

Bloomberg Philanthropies and the Bill & Melinda Gates Foundation.

Subnational mapping of HIV incidence and mortality among individuals aged 15-49 years in sub-Saharan Africa, 2000-18: a modelling study

BACKGROUND

High-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa.

METHODS

In this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15-49 years. We used a model-based geostatistical framework to estimate HIV prevalence at the second administrative level in 44 countries in sub-Saharan Africa for 2000-18 and sought data on the number of individuals on antiretroviral therapy (ART) by second-level administrative unit. We then modified the Estimation and Projection Package (EPP) to use these HIV prevalence and treatment estimates to estimate HIV incidence and mortality by second-level administrative unit.

FINDINGS

The estimates suggest substantial variation in HIV incidence and mortality rates both between and within countries in sub-Saharan Africa, with 15 countries having a ten-times or greater difference in estimated HIV incidence between the second-level administrative units with the lowest and highest estimated incidence levels. Across all 44 countries in 2018, HIV incidence ranged from 2·8 (95% uncertainty interval 2·1-3·8) in Mauritania to 1585·9 (1369·4-1824·8) cases per 100 000 people in Lesotho and HIV mortality ranged from 0·8 (0·7-0·9) in Mauritania to 676·5 (513·6-888·0) deaths per 100 000 people in Lesotho. Variation in both incidence and mortality was substantially greater at the subnational level than at the national level and the highest estimated rates were accordingly higher. Among second-level administrative units, Guijá District, Gaza Province, Mozambique, had the highest estimated HIV incidence (4661·7 [2544·8-8120·3]) cases per 100 000 people in 2018 and Inhassunge District, Zambezia Province, Mozambique, had the highest estimated HIV mortality rate (1163·0 [679·0-1866·8]) deaths per 100 000 people. Further, the rate of reduction in HIV incidence and mortality from 2000 to 2018, as well as the ratio of new infections to the number of people living with HIV was highly variable. Although most second-level administrative units had declines in the number of new cases (3316 [81·1%] of 4087 units) and number of deaths (3325 [81·4%]), nearly all appeared well short of the targeted 75% reduction in new cases and deaths between 2010 and 2020.

INTERPRETATION

Our estimates suggest that most second-level administrative units in sub-Saharan Africa are falling short of the targeted 75% reduction in new cases and deaths by 2020, which is further compounded by substantial within-country variability. These estimates will help decision makers and programme implementers expand access to ART and better target health resources to higher burden subnational areas.

FUNDING

Bill & Melinda Gates Foundation.

Preconception depression and anxiety symptoms and maternal-infant bonding: a 20-year intergenerational cohort study

Early maternal-infant bonding problems are often forerunners of later emotional and behavioural difficulties. Interventions typically target the perinatal period but many risks may be established well before pregnancy. Here we examine the extent to which adolescent and young adult depression and anxiety symptoms predict perinatal maternal-infant bonding difficulties. The Victorian Intergenerational Health Cohort Study (VIHCS, est. 2006) is following offspring born to the Victorian Adolescent Health Cohort Study (VAHCS; est. 1992). VAHCS participants were assessed for depression and anxiety symptoms nine times during adolescence and young adulthood (age 14-29 years), and then contacted bi-annually (from age 29-35 years) to identify pregnancies. The Postpartum Bonding Questionnaire (PBQ) was administered to mothers at 2 and 12 months postpartum. A total of 395 women (606 infants) completed the 2-month and/or 12-month postpartum interviews. For most infants (64%), mothers had experienced depression and/or anxiety before pregnancy. Preconception depression and anxiety symptoms that persisted from adolescence into young adulthood predicted maternal-infant bonding problems at 2 months (β = 0.30, 95% CI 0.04, 0.55) and 12 months postpartum (β = 0.40, 95% CI 0.16, 0.63). Depression and anxiety symptoms occurring in young adulthood only, also predicted bonding problems at 12 months postpartum (β = 0.37, 95% CI 0.02, 0.71). Associations between preconception depression and anxiety symptoms and anxiety-related maternal-infant bonding problems at 12 months postpartum remained after adjustment for antenatal and concurrent postpartum depressive symptoms. This study puts forward a case for extending preconception health care beyond contraception and nutrition to a broader engagement in supporting the mental health of young women from adolescence.