Common Core Assessments in follow-up studies of adults born preterm-Recommendation of the Adults Born Preterm International Collaboration

Recommendations for data collection in cohort studies of preterm born individuals - The RECAP Preterm Core Dataset

BACKGROUND

Preterm birth (before 37 completed weeks of gestation) is associated with an increased risk of adverse health and developmental outcomes relative to birth at term. Existing guidelines for data collection in cohort studies of individuals born preterm are either limited in scope, have not been developed using formal consensus methodology, or did not involve a range of stakeholders in their development. Recommendations meeting these criteria would facilitate data pooling and harmonisation across studies.

OBJECTIVES

To develop a Core Dataset for use in longitudinal cohort studies of individuals born preterm.

METHODS

This work was carried out as part of the RECAP Preterm project. A systematic review of variables included in existing core outcome sets was combined with a scoping exercise conducted with experts on preterm birth. The results were used to generate a draft core dataset. A modified Delphi process was implemented using two stages with three rounds each. Three stakeholder groups participated: RECAP Preterm project partners; external experts in the field; people with lived experience of preterm birth. The Delphi used a 9-point Likert scale. Higher values indicated greater importance for inclusion. Participants also suggested additional variables they considered important for inclusion which were voted on in later rounds.

RESULTS

An initial list of 140 data items was generated. Ninety-six participants across 22 countries participated in the Delphi, of which 29% were individuals with lived experience of preterm birth. Consensus was reached on 160 data items covering Antenatal and Birth Information, Neonatal Care, Mortality, Administrative Information, Organisational Level Information, Socio-economic and Demographic information, Physical Health, Education and Learning, Neurodevelopmental Outcomes, Social, Lifestyle and Leisure, Healthcare Utilisation and Quality of Life.

CONCLUSIONS

This core dataset includes 160 data items covering antenatal care through outcomes in adulthood. Its use will guide data collection in new studies and facilitate pooling and harmonisation of existing data internationally.

Foveal thickness and its association with visual acuity in adults born preterm with very low birth weight: A two-country birth cohort study

PURPOSE

To explore foveal and parafoveal thickness in adults born preterm with very low birth weight (VLBW) and its association with best-corrected visual acuity (BCVA) and gestational age (GA) compared to adults born at term.

METHODS

In a joint study of the Helsinki Study of Very Low Birth Weight Adults (Finland) and the NTNU Low Birth Weight Life study (Norway), 106 VLBW and 143 term-born controls were examined with spectral-domain optical coherence tomography and BCVA at age 31-43 years. Thickness of retinal layers was segmented in the foveal and parafoveal areas of the macula.

RESULTS

The total retinal thickness in the foveal area was thicker in VLBW adults compared with controls; mean (SD): 292.5 μm (28.2) and 272.4 μm (20.2); p < 0.001, and thinner in the parafoveal areas of the macula. These findings could be explained by a thicker inner retinal layer in the foveal area found in VLBW adults compared with controls (mean difference 20.4 μm; CI: 15.0 to 25.9), where a thicker fovea was associated with lower GA, but not BCVA.

CONCLUSION

Adults born preterm with VLBW had a thicker retina in the foveal area than controls and this was associated with GA, but not with BCVA. These changes seem to be related to a thicker inner retinal layer in VLBW adults. The findings imply that signs of macular underdevelopment are still present in adulthood, but not necessarily related to reduced visual function.

Cognition, mental health and quality of life amongst siblings of preterm born children: A systematic review

AIM

Globally, 1 in 10 babies are born preterm. Families with preterm born infants may suffer strains related to the presence of a preterm child. To date, most evidence focuses on the outcome of children born preterm and of their parents. Our objective was to investigate the evidence on the impact of having a preterm born sibling on cognitive function, mental health and quality of life of term-born siblings and critically appraise the evidence.

METHODS

We searched five electronic databases, Google Scholar and reference lists. Two reviewers independently conducted screening, data extraction and critical appraisal.

RESULTS

We retrieved 9121 articles. After duplicates, titles, abstract and full text review, seven studies met the inclusion criteria. One study reported higher anxiety and depression scores on index cases in the term born comparison group, compared to the index cases in the preterm born sibling group. Another study reported more feelings of reduced parental attention, and more interpersonal problems in the preterm born sibling group, than the comparison group.

CONCLUSIONS

Although two studies reported a difference in outcomes between index cases in preterm born sibling groups and comparison groups, the scarce evidence did not allow us to delineate an effect or lack of it.

Visual function in adults born preterm with very low birth weight-A two-country birth cohort study

PURPOSE

The purpose of the study was to investigate visual function and vision-related general health in adults that were born preterm with very low birth weight (VLBW: birth weight < 1500 g) in their 30s-40s.

METHODS

We recruited 137 adults born preterm with VLBW and 158 term-born controls aged 31-43 years from two birth cohorts: the Helsinki Study of Very Low Birth Weight Adults (Finland) and the NTNU Low Birth Weight in a Lifetime Perspective study (Norway). We used neonatal data and measured refraction, best-corrected visual acuity (BCVA) using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, contrast sensitivity, visual fields, intraocular pressure (IOP), self-reported vision-targeted health status with the National Eye Institute Visual Function Questionnaire-25.

RESULTS

VLBW adults had a lower BCVA ETDRS score than controls: mean (SD) better eye 86.7 (13.4) versus 90.2 (4.4), p = 0.02; mean (SD) worse eye 82.3 (14.9) versus 87.6 (4.6), p = 0.003. VLBW adults also had lower contrast sensitivity thresholds in several spatial frequencies and scored lower than controls in eight out of the 12 subscales of self-reported vision-targeted health status. Refraction, visual fields and IOP were similar between groups. Two VLBW participants were blind. None had been treated for retinopathy of prematurity.

CONCLUSION

We suggest that lower visual function and vision-related health represent life-long consequences of prematurity and VLBW in the studied 31- to 43-year-old cohort. The underlying mechanisms remain to be determined.

Late effects of prematurity: Psychiatric outcomes of 17-year-olds born very preterm

AIM

Very preterm (VPT) birth is a known early vulnerability factor, impacting both physical and mental health over the life-span. The additional burden of psychiatric illness in VPT adolescents is likely to adversely affect critical developmental tasks and personal, social and academic/vocational trajectories. Our aim was to examine the magnitude and extent of the risk of psychological burden by determining the prevalence of psychiatric disorders in our prospectively followed-up VPT and full-term (FT) control cohorts, in this period of developmental transition at age 17 years.

METHODS

Rates of psychiatric disorder in the VPT and FT control cohorts were ascertained at clinical interview of the adolescents and their care giver(s) by an adolescent psychiatrist.

RESULTS

VPT birth was associated with a greater risk of generalised anxiety disorder (VPT vs. FT risk ratio (RR) 2.33; 95% confidence interval (CI): 1.16, 4.67, P = 0.02), as well as attentional problems (VPT vs. FT RR 3.46; 95% CI: 1.01, 11.88, P = 0.03). Although care givers of VPT adolescents reported many social and communication difficulties, and observation at clinical interview supported this, our data did not reach clinical threshold for group differences in autistic spectrum disorder. For all other psychiatric disorders, there was no difference between VPT and FT control adolescents.

CONCLUSION

Our longitudinal cohort follow-up study examining the late effects of VPT birth has demonstrated increased rates of clinically significant psychiatric disorder in this period of important developmental transition. Families and health professionals need to be aware of the increased risk so they can monitor for symptoms and seek effective mental health treatments and support.

Using Digital Tools to Study the Health of Adults Born Preterm at a Large Scale: e-Cohort Pilot Study

BACKGROUND

Preterm birth is a global health concern. Its adverse consequences may persist throughout the life course, exerting a potentially heavy burden on families, health systems, and societies. In high-income countries, the first children who benefited from improved care are now adults entering middle age. However, there is a clear gap in the knowledge regarding the long-term outcomes of individuals born preterm.

OBJECTIVE

This study aimed to assess the feasibility of recruiting and following up an e-cohort of adults born preterm worldwide and provide estimations of participation, characteristics of participants, the acceptability of questions, and the quality of data collected.

METHODS

We implemented a prospective, open, observational, and international e-cohort pilot study (Health of Adult People Born Preterm-an e-Cohort Pilot Study [HAPP-e]). Inclusion criteria were being an adult (aged ≥18 years), born preterm (<37 weeks of gestation), having internet access and an email address, and understanding at least 1 of the available languages. A large, multifaceted, and multilingual communication strategy was established. Between December 2019 and June 2021, inclusion and repeated data collection were performed using a secured web platform. We provided descriptive statistics regarding participation in the e-cohort, namely, the number of persons who registered on the platform, signed the consent form, initiated and completed the baseline questionnaire, and initiated and completed the follow-up questionnaire. We also described the main characteristics of the HAPP-e participants and provided an assessment of the quality of the data and the acceptability of sensitive questions.

RESULTS

As of December 31, 2020, a total of 1004 persons had registered on the platform, leading to 527 accounts with a confirmed email and 333 signed consent forms. A total of 333 participants initiated the baseline questionnaire. All participants were invited to follow-up, and 35.7% (119/333) consented to participate, of whom 97.5% (116/119) initiated the follow-up questionnaire. Completion rates were very high both at baseline (296/333, 88.9%) and at follow-up (112/116, 96.6%). This sample of adults born preterm in 34 countries covered a wide range of sociodemographic and health characteristics. The gestational age at birth ranged from 23+6 to 36+6 weeks (median 32, IQR 29-35 weeks). Only 2.1% (7/333) of the participants had previously participated in a cohort of individuals born preterm. Women (252/333, 75.7%) and highly educated participants (235/327, 71.9%) were also overrepresented. Good quality data were collected thanks to validation controls implemented on the web platform. The acceptability of potentially sensitive questions was excellent, as very few participants chose the "I prefer not to say" option when available.

CONCLUSIONS

Although we identified room for improvement in specific procedures, this pilot study confirmed the great potential for recruiting a large and diverse sample of adults born preterm worldwide, thereby advancing research on adults born preterm.

Long-lasting effects of very preterm birth on brain structure in adulthood: A systematic review and meta-analysis

Early life experiences, such as very preterm (VP) birth, can affect brain and cognitive development. Several prior studies investigated brain structure in adults born VP; synthesising these studies may help to provide a clearer understanding of long-term effects of VP birth on the brain. We systematically searched Medline and Embase for articles that investigated brain structure using MRI in adulthood in individuals born VP (<32 weeks' gestation) or with very low birth weight (VLBW; <1500 g), and controls born at term or with normal birth weight. In total, 77 studies met the review inclusion criteria, of which 28 studies were eligible for meta-analyses, including data from up to 797 VP/VLBW participants and 518 controls, aged 18-33 years. VP/VLBW adults exhibited volumetric, morphologic and microstructural alterations in subcortical and temporal cortical regions compared with controls, with pooled standardised mean differences up to - 1.0 (95% confidence interval: -1.2, -0.8). This study suggests there is a persisting neurological impact of VP birth, which may provide developmental neurobiological insights for adult cognition in high-risk populations.

Outcomes of Preterm Infants: Shifting Focus, Extending the View

Advances in perinatal care have led to remarkable long-term survival for infants who are born preterm. This article reviews the broader context of follow-up care, highlighting the need to reenvision some areas, such as improving parental support by embedding parental involvement in the neonatal intensive care unit, incorporating parental perspectives about outcomes into follow-up care models and research, supporting their mental health, addressing social determinants of health and disparities, and advocating for change. Multicenter quality improvement networks allow identification and implementation of best practices for follow-up care.

Long-term follow-up of self-reported mental health and health-related quality of life in adults born extremely preterm

BACKGROUND

Survival of extremely preterm (EP) birth is increasing, but long-term consequences are still largely unknown as their high survival rates are recent achievements.

AIMS

To examine self-reported mental health, and health related quality of life (HRQoL) in a cohort of adults born EP in the early 1990s and individually matched term-born controls, and to describe development through the transition from teenager to adults.

METHODS

Thirty-five eligible subjects were born at gestational age ≤ 28 weeks or with birth weight ≤ 1000 g during 1991-1992 in this population-based cohort from Western Norway. We assessed mental health using Youth Self-Report (YSR) at 18 years of age, and Adult Self-Report (ASR) at 27 years, and HRQoL by RAND-36 at 27 years. Data were analysed by unadjusted and adjusted mixed effects models with time by group as interaction term.

RESULTS

At 27 years, 24 (69 %) EP-born and 26 (74 %) term-born controls participated. Scores for internalising problems, and syndrome scale anxious/depressed and withdrawn were higher among EP-born compared to term-born controls. For HRQoL, scores were similar in EP-born and term-born groups, except the domain physical functioning where EP-born scored lower. Development over time from 18 to 27 years showed increasing (i.e. deteriorating) scores for internalising, anxious/depressed, somatic complaints, and attention problems in the EP born group. For the term-born, scores for anxious/depression increased over time.

CONCLUSIONS

At 27 years of age, EP-born adults reported more internalising problems than term-born controls, while HRQoL was relatively similar except physical functioning. Mental health problems in the EP-born increased from adolescence to adulthood.

Multidisciplinary and neuroimaging findings in preterm born very low birthweight individuals from birth to 28 years of age: A systematic review of a Norwegian prospective cohort study

BACKGROUND

Children born preterm with very low birthweight (VLBW) face long-lasting neurodevelopmental challenges, where multidisciplinary assessments are warranted. The International Classification of Functioning, Disability and Health (ICF) provides a framework for understanding and conceptualising these outcomes.

OBJECTIVES

We aimed to review clinical and neuroimaging findings from birth to adulthood in a Norwegian cohort of individuals born preterm with VLBW (gestational age <37 weeks, birthweight ≤1500 g) within the framework of ICF.

DATA SOURCES

We searched PubMed and Embase for articles reporting results of the Norwegian University of Science and Technology (NTNU) Low Birth Weight in a Lifetime Perspective study.

STUDY SELECTION AND DATA EXTRACTION

We included original articles reporting proportions of adverse outcomes, mean group differences, risk factors or associations between outcomes. Data were extracted according to ICF's two-level classification. Body functions and structures comprised outcomes of brain structures, cognition, mental health, vision, pain and physical health. Activities and participation comprised motor skills, general and social functioning, education, employment, and health-related quality of life.

SYNTHESIS

We performed a qualitative synthesis of included articles. Where mean (SD) was reported, we calculated group differences in SD units.

RESULTS

Fifty-eight publications were included. Within body functions and structures, increased prevalence of brain structure pathology, lower cognitive performance, mental health problems, visual and physical health impairments through childhood, adolescence and young adulthood were reported among preterm VLBW participants compared with controls. Within activities and participation, motor problems, lower general and social functioning, and lower academic attainment were found. Perinatal factors were associated with several outcomes, and longitudinal findings suggested persistent consequences of being born preterm with VLBW.

CONCLUSIONS

Being born preterm with VLBW has long-term influences on body functions and structures, activities and participation. The ICF is appropriate for assessing general domains of functioning and guiding the management of individuals born preterm with VLBW.

Little evidence for long-term harm from antenatal corticosteroids in a population-based very low birthweight young adult cohort

BACKGROUND

Antenatal corticosteroids (ACS) given to mothers with anticipated very preterm delivery are widely used and improve infant outcomes. Follow-up studies of the first trials of ACS have shown no adverse effects, but recently there have been concerns about possible longer-term harms.

OBJECTIVES

We aimed to assess the relationship of ACS therapy to a range of physical health and welfare measures in a cohort of very low birthweight (VLBW; <1500 g) young adults.

METHODS

Population-based cohort follow-up study. All VLBW infants born in New Zealand in 1986 were included in a prospective audit of retinopathy of prematurity. Perinatal data collection included information on ACS. At 26-30 years, 250 of 323 (77%) survivors participated, 58% having received ACS, with 229 assessed in one centre, including cardiovascular, metabolic, respiratory and neurocognitive measures. Differences in outcome between those receiving/not receiving ACS were summarised by the mean difference for continuous outcomes supplemented by Cohen's d as a standardised measure of effect size (ES), and risk ratios (RRI) for dichotomous outcomes, adjusted for relevant covariates using generalised linear regression methods.

RESULTS

There were no or minimal adverse effects of receipt of ACS versus no receipt across a range of health and welfare outcomes, both for the full cohort (adjusted ES range d = 0.01-0.23; adjusted RR range 0.78-2.03) and for individuals with gestation <28 weeks (extremely preterm; EP), except for a small increase in rates of major depression. In EP adults, receipt of ACS was associated with a higher incidence of hypertension, but might have a small benefit for IQ.

CONCLUSIONS

In this population-based VLBW cohort, we detected minimal adverse outcomes associated with exposure to ACS by the third decade of life, a similar result to the 30-year follow-up of participants in the first ACS trial. However, further follow-up is warranted.

The challenges of heterogeneity in gestational age and birthweight inclusion criteria for research synthesis on very preterm birth and childhood cognition: An umbrella review and meta-regression analysis

BACKGROUND

Meta-analyses of studies on very preterm (VPT) birth and childhood cognition select primary studies using gestational age inclusion criteria only, while others also include birthweight criteria. The consequences of this choice are unknown.

OBJECTIVE

The objective of this study was to describe the gestational age (GA) and birthweight (BW) criteria used in studies of VPT birth and cognition and to investigate whether meta-analysis results differ based on these criteria.

DATA SOURCES

Five systematic reviews on VPT birth and childhood IQ.

STUDY SELECTION AND DATA EXTRACTION

Country, birth years, GA-BW selection criteria and participant IQ were extracted from 156 studies representing 103 birth cohorts.

SYNTHESIS

Pooled standardised mean differences (SMD) in IQ between children born VPT and term-born controls were estimated by sub-group based on GA-BW criteria (GA, BW and GA-BW combined) and degree of preterm birth-low birthweight combinations: extremely preterm (EPT, <28 weeks) and extremely low BW (ELBW, <1000 g); VPT (<32 weeks) and very low BW (VLBW, <1500 g); and moderately MPT (<34 weeks) and moderately low BW (MLBW, <1800 g).

RESULTS

Cohorts used 27 distinct GA-BW inclusion criteria. Most common criteria were BW <1500 g (24 cohorts), BW <1000 g (12), GA <32 weeks (12) and GA <33 weeks (12); 23 studies used GA-BW combinations. BW-only criteria were more frequent in North America than Europe (63% versus 24%) and for cohorts before than after 1990 (67% vs 26%). Pooled SMD in IQ varied: SMD_EPT/ELBW -0.94, 95% confidence interval [CI] -1.07, -0.82; SMD_VPT/VLBW -0.78, 95% CI -0.85, -0.71; SMD_MPT/MLBW -0.68, 95% CI -0.79, -0.57; however, there was no difference in SMD across cohorts using BW compared to GA criteria after adjustment on risk group.

CONCLUSIONS

These findings support the inclusion of studies using GA and/or BW criteria in meta-analyses on VPT birth and cognition to increase the geographical and temporal generalisability of the results and to allow investigation of the impact of the heterogeneous inclusion criteria in this literature on outcomes.

Mathematical performance in childhood and early adult outcomes after very preterm birth: an individual participant data meta-analysis

AIM

To investigate the strength of the independent associations of mathematics performance in children born very preterm (<32wks' gestation or <1500g birthweight) with attending postsecondary education and their current employment status in young adulthood.

METHOD

We harmonized data from six very preterm birth cohorts from five different countries and carried out one-stage individual participant data meta-analyses (n=954, 52% female) using mixed effects logistic regression models. Mathematics scores at 8 to 11 years of age were z-standardized using contemporary cohort-specific controls. Outcomes included any postsecondary education, and employment/education status in young adulthood. All models were adjusted for year of birth, gestational age, sex, maternal education, and IQ in childhood.

RESULTS

Higher mathematics performance in childhood was independently associated with having attended any postsecondary education (odds ratio [OR] per SD increase in mathematics z-score: 1.36 [95% confidence interval {CI}: 1.03, 1.79]) but not with current employment/education status (OR 1.14 per SD increase [95% CI: 0.87, 1.48]).

INTERPRETATION

Among populations born very preterm, childhood mathematics performance is important for adult educational attainment, but not for employment status.

Psychiatric disorders in individuals born very preterm / very low-birth weight: An individual participant data (IPD) meta-analysis

BACKGROUND

Data on psychiatric disorders in survivors born very preterm (VP; <32 weeks) or very low birthweight (VLBW; <1500 g) are sparse. We compared rates of psychiatric diagnoses between VP/VLBW and term-born, normal birthweight (term/NBW) control participants.

METHODS

This individual participant data (IPD) meta-analysis pooled data from eligible groups in the Adults born Preterm International Collaboration (APIC). Inclusion criteria included: 1) VP/VLBW group (birth weight <1500 g and/or gestational age <32 weeks), 2) normal birth weight/term-born control group (birth weight >2499 g and/or gestational age ≥37 weeks), and 3) structured measure of psychiatric diagnoses using DSM or ICD criteria. Diagnoses of interest were Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Anxiety Disorder, Mood Disorder, Disruptive Behaviour Disorder (DBD), Eating Disorder, and Psychotic Disorder. A systematic search for eligible studies was conducted (PROSPERO Registration Number 47555).

FINDINGS

Data were obtained from 10 studies (1385 VP/VLBW participants, 1780 controls), using a range of instruments and approaches to assigning diagnoses. Those born VP/VLBW had ten times higher odds of meeting criteria for ASD (odds ratio [OR] 10·6, 95% confidence interval [CI] 2·50, 44·7), five times higher odds of meeting criteria for ADHD (OR 5·42, 95% CI 3·10, 9·46), twice the odds of meeting criteria for Anxiety Disorder (OR 1·91, 95% CI 1·36, 2·69), and 1·5 times the odds of meeting criteria for Mood Disorder (OR 1·51, 95% CI 1·08, 2·12) than controls. This pattern of findings was consistent within age (<18 years vs. ≥18 years) and sex subgroups.

INTERPRETATION

Our data suggests that individuals born VP/VLBW might have higher odds of meeting criteria for certain psychiatric disorders through childhood and into adulthood than term/NBW controls. Further research is needed to corroborate our results and identify factors associated with psychiatric disorders in individuals born VP/VLBW.

FUNDING

Australia's National Health & Medical Research Council; CAPES (Coordenação de Aperfeiçoamento de Pessoal deNível Superior) - International Cooperation General Program; Canadian Institutes of Health Research Team Grant; National Council for Scientific and Technological Development (CNPq); Academy of Finland; Sigrid Juselius Foundation; Signe and Ane Gyllenberg Foundation; European Union's Horizon 2020 research and innovation programme: Project RECAP-Preterm; European Commission Dynamics of Inequality Across the Life-course: structures and processes (DIAL); Neurologic Foundation of New Zealand; MRC programme grant; Health Research Council of New Zealand; National Institutes of Health, USA; The Research Council of Norway; Joint Research Committee between St. Olavs Hospital and Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU); Liaison Committee between Central Norway Regional Health Authority and NTNU.