Do population-based interventions widen or narrow socioeconomic inequalities? The case of breastfeeding promotion

Inequalities in large-scale breastfeeding programmes in Bangladesh, Burkina Faso and Vietnam

Inequalities in breastfeeding programmes and practices have slowed global progress in providing the life-saving protection of breastfeeding for millions of infants despite well-known life-long impacts. As breastfeeding interventions are scaled up, inequalities in coverage and breastfeeding practices should be tracked, particularly in disadvantaged groups, who are likely to suffer the most serious health and developmental impacts of poor childhood nutrition. The literature provides evidence of inequalities in breastfeeding practices, but research is limited on socioeconomic disparities in the coverage of breastfeeding interventions. This paper (1) compares inequalities in breastfeeding practices in intervention and nonintervention areas and (2) documents inequalities in programme coverage by type of intervention. We disaggregated endline evaluation surveys in Bangladesh, Burkina Faso and Vietnam, where rigorous evaluations had documented significant overall improvements, and analysed whether inequalities in breastfeeding practices and programme coverage differed by treatment areas. We used Erreygers index to quantify inequalities and found that breastfeeding practices were largely pro-poor; intervention coverage was not consistently pro-poor. While counselling coverage often favoured women from the poorest quintile, public education/media coverage consistently favoured better-off women. Inequalities favoured more educated mothers in the coverage of combined interventions. None of the programmes had explicit equality objectives. The results indicate the need for introducing specific actions to reduce inequalities in breastfeeding policies and programmes. This is a priority unfinished agenda for nutrition programming.

Support for healthy breastfeeding mothers with healthy term babies

BACKGROUND

There is extensive evidence of important health risks for infants and mothers related to not breastfeeding. In 2003, the World Health Organization recommended that infants be breastfed exclusively until six months of age, with breastfeeding continuing as an important part of the infant's diet until at least two years of age. However, current breastfeeding rates in many countries do not reflect this recommendation.

OBJECTIVES

1. To describe types of breastfeeding support for healthy breastfeeding mothers with healthy term babies. 2. To examine the effectiveness of different types of breastfeeding support interventions in terms of whether they offered only breastfeeding support or breastfeeding support in combination with a wider maternal and child health intervention ('breastfeeding plus' support).  3. To examine the effectiveness of the following intervention characteristics on breastfeeding support:      a. type of support (e.g. face-to-face, telephone, digital technologies, group or individual support, proactive or reactive);      b. intensity of support (i.e. number of postnatal contacts);      c. person delivering the intervention (e.g. healthcare professional, lay person);     d. to examine whether the impact of support varied between high- and low-and middle-income countries.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (which includes results of searches of CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP)) (11 May 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing extra support for healthy breastfeeding mothers of healthy term babies with usual maternity care. Support could be provided face-to-face, over the phone or via digital technologies. All studies had to meet the trustworthiness criteria.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane Pregnancy and Childbirth methods. Two review authors independently selected trials, extracted data, and assessed risk of bias and study trustworthiness.  The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

This updated review includes 116 trials of which 103 contribute data to the analyses. In total more than 98,816 mother-infant pairs were included.  Moderate-certainty evidence indicated that 'breastfeeding only' support probably reduced the number of women stopping breastfeeding for all primary outcomes: stopping any breastfeeding at six months (Risk Ratio (RR) 0.93, 95% Confidence Interval (CI) 0.89 to 0.97); stopping exclusive breastfeeding at six months (RR 0.90, 95% CI 0.88 to 0.93); stopping any breastfeeding at 4-6 weeks (RR 0.88, 95% CI 0.79 to 0.97); and stopping exclusive breastfeeding at 4-6 (RR 0.83 95% CI 0.76 to 0.90). Similar findings were reported for the secondary breastfeeding outcomes except for any breastfeeding at two months and 12 months when the evidence was uncertain if 'breastfeeding only' support helped reduce the number of women stopping breastfeeding.  The evidence for 'breastfeeding plus' was less consistent. For primary outcomes there was some evidence that 'breastfeeding plus' support probably reduced the number of women stopping any breastfeeding (RR 0.94, 95% CI 0.91 to 0.97, moderate-certainty evidence) or exclusive breastfeeding at six months (RR 0.79, 95% CI 0.70 to 0.90).  'Breastfeeding plus' interventions may have a beneficial effect on reducing the number of women stopping exclusive breastfeeding at 4-6 weeks, but the evidence is very uncertain (RR 0.73, 95% CI 0.57 to 0.95). The evidence suggests that 'breastfeeding plus' support probably results in little to no difference in the number of women stopping any breastfeeding at 4-6 weeks (RR 0.94, 95% CI 0.82 to 1.08, moderate-certainty evidence). For the secondary outcomes, it was uncertain if 'breastfeeding plus' support helped reduce the number of women stopping any or exclusive breastfeeding at any time points.  There were no consistent findings emerging from the narrative synthesis of the non-breastfeeding outcomes (maternal satisfaction with care, maternal satisfaction with feeding method, infant morbidity, and maternal mental health), except for a possible reduction of diarrhoea in intervention infants.  We considered the overall risk of bias of trials included in the review was mixed. Blinding of participants and personnel is not feasible in such interventions and as studies utilised self-report breastfeeding data, there is also a risk of bias in outcome assessment.   We conducted meta-regression to explore substantial heterogeneity for the primary outcomes using the following categories: person providing care; mode of delivery; intensity of support; and income status of country.  It is possible that moderate levels (defined as 4-8 visits) of 'breastfeeding only' support may be associated with a more beneficial effect on exclusive breastfeeding at 4-6 weeks and six months. 'Breastfeeding only' support may also be more effective in reducing women in low- and middle-income countries (LMICs) stopping exclusive breastfeeding at six months compared to women in high-income countries (HICs). However, no other differential effects were found and thus heterogeneity remains largely unexplained. The meta-regression suggested that there were no differential effects regarding person providing support or mode of delivery, however, power was limited.  AUTHORS' CONCLUSIONS: When 'breastfeeding only' support is offered to women, the duration and in particular, the exclusivity of breastfeeding is likely to be increased. Support may also be more effective in reducing the number of women stopping breastfeeding at three to four months compared to later time points.  For 'breastfeeding plus' interventions the evidence is less certain. Support may be offered either by professional or lay/peer supporters, or a combination of both. Support can also be offered face-to-face, via telephone or digital technologies, or a combination and may be more effective when delivered on a schedule of four to eight visits. Further work is needed to identify components of the effective interventions and to deliver interventions on a larger scale.

Trends and inequalities in breastfeeding continuation from 1 to 6 weeks: findings from six population-based British cohorts, 1985-2010

BACKGROUND

Understanding inequalities in breastfeeding practices may help to explain the UK's persistently low breastfeeding rates. A recent study using the quinquennial UK Infant Feeding Surveys (IFS) found that sociodemographic inequalities in breastfeeding initiation persisted between 1985 and 2010. The present study investigates the sociodemographic inequalities in breastfeeding continuation at 6 weeks after birth among mothers who initiated and maintained breastfeeding at 1 week in 1985-2010.

METHODS

Data were drawn from the 1985 to 2010 IFS and restricted to mothers who were breastfeeding at 1 week after birth. Time trends in the proportion of mothers in each sociodemographic group were examined. Logistic regression was used to estimate associations between breastfeeding at 6 weeks and sociodemographic factors, adjusting for confounders. Heterogeneity test was used to assess changes in these associations over time.

RESULTS

Sociodemographic inequalities in breastfeeding continuation at 6 weeks persisted over the 25-year period. In most survey years, mothers were most likely to breastfeed at 6 weeks if they were 30 or older versus under 25 (OR 1.49-1.99 across survey years, I²= 0%, heterogeneity P = 0.45); completed full-time education over age 18 compared to 18 or younger (OR 1.56-2.51, I²= 58.7%, P = 0.03); or of Black, Asian, Mixed, or other ethnicity compared to White (OR 1.45-2.48, I²= 44.8%, P = 0.16).

CONCLUSIONS

Among mothers breastfeeding at 1 week, those who were younger, White or had fewer years of full-time education were at greatest risk of discontinuing before 6 weeks. This risk persisted over time and was independent of their high risk of not initiating breastfeeding.

Factors related to inhibition of lactation by pharmacological means at birth in a Spanish referral hospital (2011-2017)

OBJECTIVE

To describe the maternal, neonatal and pregnancy characteristics related to inhibition of lactation (IL) with cabergoline.

METHOD

We assessed 20,965 occasions of breastfeeding initiation, according to data collected from obstetric records at the Hospital Clinic of Barcelona (Spain) between January 2011 and December 2017.

RESULTS

IL decreased over the study period from 8.78% to 6.18% (odds ratio [OR]: 0.93 per year; 95% confidence interval [95%CI]: 0.90-0.95). Women with a lower educational level (OR: 2.5; 95%CI: 2.0-3.0), mothers living in more depressed areas (OR: 1.08 per 10 extra points over 100; 95%CI: 1.04-1.12), smokers (OR: 2.2; 95%CI: 1.9-2.6), and those with more children (OR: 1.2 for each sibling; 95%CI: 1.1-1.3), preterm birth (OR: 1.8; 95%CI: 1.4-2.3), multiple births (OR: 1.6; 95%CI: 1.2-2.1) and a higher risk pregnancy (OR: 1.3 per risk point; 95%CI: 1.2-1.4) showed a higher prevalence of IL. Compared to women born in Spain, IL was less likely in all other women with the exception of Chinese women (OR: 7.0; 95%CI: 5.7-8.6). These disparities remained during the study period.

CONCLUSIONS

Factors related to lower socioeconomic status and poor health were more likely to be associated with IL. The overall use of cabergoline decreased during the study period while inequalities persisted. Taking these inequalities into account is the first step to addressing them.

A retrospective on fundamental cause theory: State of the literature, and goals for the future

Fundamental Cause Theory (FCT) was originally proposed to explain how socioeconomic inequalities in health emerged and persisted over time. The concept was that higher socioeconomic status helped some people to avoid risks and adopt protective strategies using flexible resources - knowledge, money, power, prestige and beneficial social connections. As a sociological theory, FCT addressed this issue by calling on social stratification, stigma, and racism as they affected medical treatments and health outcomes. The last comprehensive review was completed a decade ago. Since then, FCT has been tested, and new applications have extended central features. The current review consolidates key foci in the literature in order to guide future research in the field. Notable themes emerged around types of resources and their usage, approaches used to test the theory, and novel extensions. We conclude that after 25 years of use, there remain crucial questions to be addressed.

The Impact of Socio-Demographic Factors on Breastfeeding: Findings from the "Mamma & Bambino" Cohort

Background and objectives: The World Health Organization (WHO) recommends women (1) to initiate breastfeeding within one hour of birth; (2) to exclusively breastfeed for the first six months; and (3) to continue breastfeeding until two years of age. However, women do not always adhere to these recommendations, threatening the health of their children. The present study aims to evaluate breastfeeding status and the main maternal factors associated with exclusive breastfeeding for six months among women from the "Mamma & Bambino" study, a prospective cohort settled in Catania, Italy. Materials and Methods: We used data from 220 women (median age = 37 years) enrolled in the "Mamma & Bambino" cohort during prenatal obstetric counselling. Self-reported breastfeeding status was collected during the follow-up interviews at 1 and 2 years, referring to breastfeeding status (i.e., yes or no) and type of breastfeeding (i.e., exclusive or predominant). We also collected data about duration of breastfeeding to classify women into those who adhered to the WHO recommendation and those who did not. Results: In the general population, we noted that the proportion of women who have breastfed increased with increasing educational level. Accordingly, logistic regression analysis demonstrated that medium (OR = 3.171; 95% CI = 1.285-7.822; p = 0.012) and high educational levels (OR = 4.549; 95% CI = 1.525-13.570; p = 0.007) were positively associated with breastfeeding if compared to low educational level. Among women who have breastfed, instead, the proportion of adherents to the WHO recommendation was higher among those with medium-high educational level and those who were employed. In line with this, we demonstrated that full-time employment (OR = 2.158; 95% CI = 1.033-4.508; p = 0.041) and medium educational level (OR = 4.632; 95% CI = 1.227-17.484; p = 0.024) were positively associated with exclusive breastfeeding for the first six months. Conclusions: Socio-demographic factors should be taken into account through public health strategies for improving maternal knowledge about health benefits of exclusive breastfeeding.

Fundamental social causes of inequalities in colorectal cancer mortality: A study of behavioral and medical mechanisms

BACKGROUND

Fundamental cause theory posits that social conditions strongly influence the risk of health risks. This study identifies risk mechanisms that social conditions associated with socioeconomic status (SES) and race/ethnicity shape in the production of colorectal cancer (CRC) mortality.

METHODS

Two large datasets in the United States examining behavioral and medical preventive factors (N = 4.63-million people) were merged with population-level mortality data observing 761,100 CRC deaths among 3.31-billion person-years of observation to examine trends in CRC mortality from 1999-2012. Analyses examined the changing role of medical preventions and health behaviors in catalyzing SES and racial/ethnic inequalities in CRC mortality.

RESULTS

Lower SES as well as Black, Hispanic, Asian/Pacific Islander, and Native American race/ethnicity were associated with decreased access to age-appropriate screening and/or increased prevalence of behavioral risk factors. Analyses further revealed that SES and racial/ethnic inequalities were partially determined by differences in engagement in two preventive factors: use of colonoscopy, and participation in physical activity.

DISCUSSION

Social inequalities were not completely determined by behavioral risk factors. Nevertheless, a more equitable distribution of preventive medicines has the potential to reduce both the risk of, and social inequalities in, CRC mortality.

Moving Upstream: The Effect of Tobacco Clean Air Restrictions on Educational Inequalities in Smoking Among Young Adults

Education affords a range of direct and indirect benefits that promote longer and healthier lives and stratify health lifestyles. We use tobacco clean air policies to examine whether policies that apply universally-interventions that bypass individuals' unequal access and ability to employ flexible resources to avoid health hazards-have an effect on educational inequalities in health behaviors. We test theoretically informed but competing hypotheses that these policies either amplify or attenuate the association between education and smoking behavior. Our results provide evidence that interventions that move upstream to apply universally regardless of individual educational attainment-here, tobacco clean air policies-are particularly effective among young adults with the lowest levels of parental or individual educational attainment. These findings provide important evidence that upstream approaches may disrupt persistent educational inequalities in health behaviors. In doing so, they provide opportunities to intervene on behaviors in early adulthood that contribute to disparities in morbidity and mortality later in the life course. These findings also help assuage concerns that tobacco clean air policies increase educational inequalities in smoking by stigmatizing those with the fewest resources.

Does the national dental scaling policy reduce inequalities in dental scaling usage? A population-based quasi-experimental study

BACKGROUND

In 2013, the national dental scaling insurance policy was introduced in South Korea. The purpose of this study is to determine the impact of the policy on inequalities in dental scaling usage.

METHODS

Data of a nationally representative sample of 1,517,097 people over the age of 20 were obtained from the 2010-2016 Community Health Survey. Respondents who reported that they had not received dental scaling in the past year were defined as dental scaling non-users. The excess prevalence and relative prevalence ratio of dental scaling non-users were calculated for the pre-policy (2010-2012) and post-policy periods (2014-2016) using monthly household income levels. Additionally, trends of dental scaling inequalities were shown as concentration indexes.

RESULTS

The prevalence of dental scaling non-users declined from 58.0 to 48.7% in the highest income group and from 86.3 to 78.8% in the lowest income group. However, the adjusted excess prevalence for the lowest income group compared with the highest had increased from 11.9 (95% CI: 11.9-11.9) to 15.5 (95% CI: 15.5-15.5)%, and the adjusted prevalence ratio increased from 1.19 (95% CI: 1.19-1.20) to 1.29 (95% CI: 1.29-1.30). Absolute and relative concentration indexes of dental scaling non-users increased after policy implementation.

CONCLUSIONS

The national dental scaling insurance policy has increased socioeconomic inequalities in dental scaling usage. Because dental care access generally requires high individual agency, expanded dental coverage may have had limited effects in attenuating inequalities and inadvertently widened the gap. To reduce dental care inequalities, universal access with universal dental coverage should be considered.

Social Networks and the Emergence of Health Inequalities Following a Medical Advance: Examining Prenatal H1N1 Vaccination Decisions

Health inequalities persist, in part, because people in socioeconomically advantageous positions possess resources to avoid new health risks when medicine advances. Although these health decisions rarely occur in isolation, we know less about the specific role of networks. We examine whether social capital mediates the relationship between individual educational attainment and decisions about a medical advance: H1N1 vaccination during pregnancy. Building on prior work that defines social capital as the resources of network members, we examine two mechanisms through which social capital may affect health decisions, facilitating information flow and exerting influence. Using egocentric network data collected from 225 pregnant women during the 2009-10 H1N1 pandemic, we measure social capital as the proportion of networks that are college-educated H1N1 discussants (information flow) and the proportion of college-educated H1N1 supporters (influence). Findings reveal that college-educated women knew more college-educated H1N1 discussants and supporters. Further, both measures of social capital predicted higher probabilities of vaccination, with the latter mechanism emerging as a particularly strong predictor. Our findings provide evidence that health decisions are shaped by individual resources as well as social capital available through network ties, offering a unique perspective of the ways that social networks contribute to producing, and potentially reproducing, unequal health.

Hospital breastfeeding support and exclusive breastfeeding by maternal prepregnancy body mass index

Overweight and obese mothers in the United States have disproportionately lower rates of exclusive breastfeeding than mothers of normal weight. The Ten Steps to Successful Breastfeeding (Ten Steps), a series of evidence-based practices designed to support breastfeeding initiation, duration, and exclusivity, demonstrate effectiveness at the population level. It is unknown, however, whether they are consistently provided to women across all maternal body mass index (BMI) categories. We sought to determine whether pre-pregnancy BMI is associated with the implementation and effectiveness of the Ten Steps. We used data from Listening to Mothers III, a cross-sectional survey administered to a sample of mothers who delivered in U.S. hospitals between July 2011 and June 2012. Measures of the Ten Steps were based on maternal self-report on Listening to Mothers III. Our analytic sample was limited to mothers of term infants intending to breastfeed (N = 1,506, weighted). We conducted chi-square testing and constructed weighted multivariable logistic regression models to account for potential confounders. Results suggest that two practices (i.e., holding their babies skin-to-skin for the first time and being encouraged to breastfeed on demand) were more strongly associated with exclusive breastfeeding among mothers with obesity than other mothers. Additionally, mothers with obesity reported holding babies skin-to-skin significantly less often than other mothers. Thus, interventions aimed at helping mothers with obesity to hold their babies skin-to-skin in the first hour and teaching them to breastfeed on demand have the potential to decrease the breastfeeding disparities in this population.

A Pilot Study of a Culturally Grounded Breastfeeding Intervention for Pregnant, Low-Income African American Women

BACKGROUND

Increasing breastfeeding rates among low-income African American women may work toward the achievement of health equity. The dynamic breastfeeding assessment process (D-BAP) is a community-grounded, equity-focused intervention designed to increase prenatal breastfeeding self-efficacy. Research aim: The aims of the pilot study were (a) to determine the effect of the D-BAP on breastfeeding self-efficacy among pregnant, low-income African American women, (b) to examine the findings among women with no previous breastfeeding experience, and (c) to compare the findings between women with prior breastfeeding experience and those without it.

METHODS

A pre/post, paired-samples design was utilized. Convenience sampling was used to recruit pregnant, low-income African American women ( N = 25). Participants completed the Breastfeeding Self-Efficacy Scale-Short Form prior to and following the D-BAP.

RESULTS

The Wilcoxon signed rank test indicated that participation in the D-BAP had a statistically significant influence on breastfeeding self-efficacy ( z = -2.01, p = .04). Among a subsample of participants with no previous breastfeeding experience ( n = 12), completion of the D-BAP resulted in a statistically significant increase in breastfeeding self-efficacy ( z = -2.36, p = .02). There was no statistically significant difference between those with prior breastfeeding experience and those without it.

CONCLUSION

Breastfeeding among low-income African American women is a health equity issue for which culturally responsive, effective breastfeeding interventions are needed. This research demonstrates an association between completion of the D-BAP and an increase in prenatal breastfeeding self-efficacy.

Decreased Risk of Preeclampsia After the Introduction of Universal Voucher Scheme for Antenatal Care and Birth Services in the Republic of Korea

Objectives A number of interventions to reduce disparities in maternal health have been introduced and implemented without concrete evidence to support them. In Korea, a universal voucher scheme for antenatal care and birth services was initiated in December 2008 to improve Korea's fertility rate. This study explores the risk of preeclampsia after the introduction of a universal voucher scheme. Methods Population-based cohort data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) covering 2002-2013 were analysed. A generalized linear mixed model (GLMM) was used to estimate the relationship between the risk of preeclampsia and voucher scheme introduction. Results The annual age-adjusted incidence of preeclampsia showed no significant unidirectional change during the study period. In the GLMM analysis, the introduction of a voucher scheme was associated with a reduced risk of preeclampsia, controlling for potential confounding factors. The interaction between household income level and voucher scheme was not significant. Conclusions for Practice This finding suggests that the introduction of a voucher scheme for mothers is related to a reduced risk of preeclampsia even under universal health coverage.

Hospital practices to promote breastfeeding: The effect of maternal age

BACKGROUND

Breastfeeding rates are disproportionately low among young mothers in the United States. Although the use of hospital practices to promote breastfeeding is widely supported, the extent to which these practices help explain breastfeeding disparities by maternal age is unclear. Accordingly, we aimed to explore how maternal age may affect (1) receipt of hospital practices and (2) associations between these practices and exclusive breastfeeding.

METHODS

Data were derived from participants (n = 1598) of Listening to Mothers III, a national survey administered to mothers of singleton births in United States hospitals from July 2011 to June 2012. We used multivariable logistic regression models and interaction terms to examine maternal age as an effect modifier.

RESULTS

Compared with mothers aged 30 and older, mothers aged 18-19 had lower odds of reporting that nurses helped them initiate breastfeeding when ready (OR 0.59 [95% CI 0.35-0.99]), they roomed-in with their baby (OR 0.32 [95% CI 0.19-54]) and they did not receive a pacifier (OR 0.53 [95% CI 0.32-0.90]). Many associations with breastfeeding were stronger among mothers aged 18-19 and 20-24 than mothers aged 25-29 and 30 and older. Additionally, compared with receiving a pacifier, not receiving a pacifier was associated with greater odds of exclusive breastfeeding at 1 week among mothers aged 30 and older (OR 1.47 [95% CI 1.02-2.11]) but lower odds among mothers aged 18-19 (OR 0.26 [95% CI 0.10-0.70]).

CONCLUSIONS

Hospital practices to promote breastfeeding may be differentially implemented by maternal age. Encouraging teenage mothers to room-in with their babies may be particularly important for reducing breastfeeding disparities. Pacifier use among babies of teenage mothers requires further exploration.

Support for healthy breastfeeding mothers with healthy term babies

BACKGROUND

There is extensive evidence of important health risks for infants and mothers related to not breastfeeding. In 2003, the World Health Organization recommended that infants be breastfed exclusively until six months of age, with breastfeeding continuing as an important part of the infant's diet until at least two years of age. However, current breastfeeding rates in many countries do not reflect this recommendation.

OBJECTIVES

To describe forms of breastfeeding support which have been evaluated in controlled studies, the timing of the interventions and the settings in which they have been used.To examine the effectiveness of different modes of offering similar supportive interventions (for example, whether the support offered was proactive or reactive, face-to-face or over the telephone), and whether interventions containing both antenatal and postnatal elements were more effective than those taking place in the postnatal period alone.To examine the effectiveness of different care providers and (where information was available) training.To explore the interaction between background breastfeeding rates and effectiveness of support.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (29 February 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing extra support for healthy breastfeeding mothers of healthy term babies with usual maternity care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

This updated review includes 100 trials involving more than 83,246 mother-infant pairs of which 73 studies contribute data (58 individually-randomised trials and 15 cluster-randomised trials). We considered that the overall risk of bias of trials included in the review was mixed. Of the 31 new studies included in this update, 21 provided data for one or more of the primary outcomes. The total number of mother-infant pairs in the 73 studies that contributed data to this review is 74,656 (this total was 56,451 in the previous version of this review). The 73 studies were conducted in 29 countries. Results of the analyses continue to confirm that all forms of extra support analyzed together showed a decrease in cessation of 'any breastfeeding', which includes partial and exclusive breastfeeding (average risk ratio (RR) for stopping any breastfeeding before six months 0.91, 95% confidence interval (CI) 0.88 to 0.95; moderate-quality evidence, 51 studies) and for stopping breastfeeding before four to six weeks (average RR 0.87, 95% CI 0.80 to 0.95; moderate-quality evidence, 33 studies). All forms of extra support together also showed a decrease in cessation of exclusive breastfeeding at six months (average RR 0.88, 95% CI 0.85 to 0.92; moderate-quality evidence, 46 studies) and at four to six weeks (average RR 0.79, 95% CI 0.71 to 0.89; moderate quality, 32 studies). We downgraded evidence to moderate-quality due to very high heterogeneity.We investigated substantial heterogeneity for all four outcomes with subgroup analyses for the following covariates: who delivered care, type of support, timing of support, background breastfeeding rate and number of postnatal contacts. Covariates were not able to explain heterogeneity in general. Though the interaction tests were significant for some analyses, we advise caution in the interpretation of results for subgroups due to the heterogeneity. Extra support by both lay and professionals had a positive impact on breastfeeding outcomes. Several factors may have also improved results for women practising exclusive breastfeeding, such as interventions delivered with a face-to-face component, high background initiation rates of breastfeeding, lay support, and a specific schedule of four to eight contacts. However, because within-group heterogeneity remained high for all of these analyses, we advise caution when making specific conclusions based on subgroup results. We noted no evidence for subgroup differences for the any breastfeeding outcomes.

AUTHORS' CONCLUSIONS

When breastfeeding support is offered to women, the duration and exclusivity of breastfeeding is increased. Characteristics of effective support include: that it is offered as standard by trained personnel during antenatal or postnatal care, that it includes ongoing scheduled visits so that women can predict when support will be available, and that it is tailored to the setting and the needs of the population group. Support is likely to be more effective in settings with high initiation rates. Support may be offered either by professional or lay/peer supporters, or a combination of both. Strategies that rely mainly on face-to-face support are more likely to succeed with women practising exclusive breastfeeding.

The idea of uniform change: is it time to revisit a central tenet of Rose's "Strategy of Preventive Medicine"?

A mean-centric view of populations, whereby a change in the mean of a health variable at the population level is assumed to result in uniform change across the distribution, is a core component of Geoffrey Rose's concept of the "population strategy" to disease prevention. This idea also has a critical role in Rose's observation that individuals who are considered abnormal or sick (the rightward tail of the distribution) and those who are considered normal (the center) are very closely related, and that true preventive medicine must focus on shifting the normal or average. In this Perspective, we revisit these core tenets of Rose's concept of preventive medicine after providing an overview of the key concepts that he developed. We examine whether these assumptions apply to population changes in body mass index (BMI) and show that there is considerable evidence of a widening of the BMI distribution in populations over time. We argue that, with respect to BMI, the idea of using statistical measures of a population solely on the basis of means and the assumption that populations are coherent entities that change uniformly over time may not fully capture the true nature of changes in the population. These issues have important implications for how we assess and interpret the health of populations over time with implications for the balance between universal and targeted strategies aimed at improving health.

Review Article: Vulnerability to Heat-related Mortality: A Systematic Review, Meta-analysis, and Meta-regression Analysis

BACKGROUND

Addressing vulnerability to heat-related mortality is a necessary step in the development of policies dictated by heat action plans. We aimed to provide a systematic assessment of the epidemiologic evidence regarding vulnerability to heat-related mortality.

METHODS

Studies assessing the association between high ambient temperature or heat waves and mortality among different subgroups and published between January 1980 and August 2014 were selected. Estimates of association for all the included subgroups were extracted. We assessed the presence of heterogeneous effects between subgroups conducting Cochran Q tests. We conducted random effect meta-analyses of ratios of relative risks (RRR) for high ambient temperature studies. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the RRR.

RESULTS

Sixty-one studies were included. Using the Cochran Q test, we consistently found evidence of vulnerability for the elderly ages >85 years. We found a pooled RRR of 0.99 (95% confidence interval [CI] = 0.97, 1.01) for male sex, 1.02 (95% CI = 1.01, 1.03) for age >65 years, 1.04 (95% CI = 1.02, 1.07) for ages >75 years, 1.03 (95% CI = 1.01, 1.05) for low individual socioeconomic status (SES), and 1.01 (95% CI = 0.99, 1.02) for low ecologic SES.

CONCLUSIONS

We found strongest evidence of heat-related vulnerability for the elderly ages >65 and >75 years and low SES groups (at the individual level). Studies are needed to clarify if other subgroups (e.g., children, people living alone) are also vulnerable to heat to inform public health programs.

Effectiveness of Baby-friendly community health services on exclusive breastfeeding and maternal satisfaction: a pragmatic trial

The WHO/UNICEF Baby-friendly Hospital Initiative has been shown to increase breastfeeding rates, but uncertainty remains about effective methods to improve breastfeeding in community health services. The aim of this pragmatic cluster quasi-randomised controlled trial was to assess the effectiveness of implementing the Baby-friendly Initiative (BFI) in community health services. The primary outcome was exclusive breastfeeding until 6 months in healthy babies. Secondary outcomes were other breastfeeding indicators, mothers' satisfaction with the breastfeeding experience, and perceived pressure to breastfeed. A total of 54 Norwegian municipalities were allocated by alternation to the BFI in community health service intervention or routine care. All mothers with infants of five completed months were invited to participate (n = 3948), and 1051 mothers in the intervention arm and 981 in the comparison arm returned the questionnaire. Analyses were by intention to treat. Women in the intervention group were more likely to breastfeed exclusively compared with those who received routine care: 17.9% vs. 14.1% until 6 months [cluster adjusted odds ratio (OR) = 1.33; 95% confidence interval (CI): 1.03, 1.72; P = 0.03], 41.4% vs. 35.8% until 5 months [cluster adjusted OR = 1.39; 95% CI: 1.09, 1.77; P = 0.01], and 72.1% vs. 68.2% for any breastfeeding until 6 months [cluster adjusted OR = 1.24; 95% CI: 0.99, 1.54; P = 0.06]. The intervention had no effect on breastfeeding until 12 months. Maternal breastfeeding experience in the two groups did not differ, neither did perceived breastfeeding pressure from staff in the community health services. In conclusion, the BFI in community health services increased rates of exclusive breastfeeding until 6 months. © 2015 Blackwell Publishing Ltd.

Changing Societal and Lifestyle Factors and Breastfeeding Patterns Over Time

BACKGROUND

Breastfeeding is an important determinant of early infant immune function and potentially future health. Although numerous studies have reported rising breastfeeding initiation rates and duration, few longitudinally investigated the impact of shifting societal and lifestyle factors on breastfeeding patterns in developed nations.

METHODS

The Ulm Birth Cohort Study (UBCS) and Ulm SPATZ Health Study (SPATZ) cohorts consist of newborns and their mothers recruited, respectively, from 2000 to 2001 and 2012 to 2013 at the University Medical Center Ulm, Germany. Cox proportional hazards models were used to estimate crude and mutually adjusted hazard ratios for study effect (time trend) and individual risk factors on noninitiation and duration of predominant and total breastfeeding.

RESULTS

Compared with UBCS mothers, SPATZ mothers had lower cessation rates of both predominant breastfeeding by 4 months and total breastfeeding by 6 months: hazard ratio (95% confidence interval) 0.79 (0.67-0.93) and 0.71 (0.60-0.82), respectively. However, this crude time trend was limited to mothers with higher educational achievement. Similar time trend effects were observed among less educated mothers only after adjustment for early cessation risk factors. Mutually adjusted hazard ratios for individual risk factors were similar in both studies: low education, high BMI, smoking within 6 weeks of delivery, and cesarean delivery were associated with early breastfeeding cessation beginning at 6 weeks. In addition, actively abstaining from drinking alcohol was associated with lower rates of early cessation.

CONCLUSIONS

Our results suggest widening socioeconomic disparity in breastfeeding and potentially subsequent child health, which may require new targeted interventions.

High education and increased parity are associated with breast-feeding initiation and duration among Australian women

OBJECTIVE

Breast-feeding is associated with positive maternal and infant health and development outcomes. To assist identifying women less likely to meet infant nutritional guidelines, we investigated the role of socio-economic position and parity on initiation of and sustaining breast-feeding for at least 6 months.

DESIGN

Prospective cohort study.

SETTING

Australia.

SUBJECTS

Parous women from the Australian Longitudinal Study on Women's Health (born 1973-78), with self-reported reproductive and breast-feeding history (N 4777).

RESULTS

While 89 % of women (83 % of infants) had ever breast-fed, only 60 % of infants were breast-fed for at least 6 months. Multiparous women were more likely to breast-feed their first child (~90 % v. ~71 % of primiparous women), and women who breast-fed their first child were more likely to breast-feed subsequent children. Women with a low education (adjusted OR (95 % CI): 2·09 (1·67, 2·62)) or a very low-educated parent (1·47 (1·16, 1·88)) had increased odds of not initiating breast-feeding with their first or subsequent children. While fewer women initiated breast-feeding with their youngest child, this was most pronounced among high-educated women. While ~60 % of women breast-fed their first, second and third child for at least 6 months, low-educated women (first child, adjusted OR (95 % CI): 2·19 (1·79, 2·68)) and women with a very low (1·82 (1·49, 2·22)) or low-educated parent (1·69 (1·33, 2·14)) had increased odds of not breast-feeding for at least 6 months.

CONCLUSIONS

A greater understanding of barriers to initiating and sustaining breast-feeding, some of which are socio-economic-specific, may assist in reducing inequalities in infant breast-feeding.

Physiological mechanisms, behavioral and psychological factors influencing the transfer of milk from mothers to their young

This article is part of a Special Issue "Parental Care".Producing milk to support the growth of their young is a central element of maternal care in mammals. In spite of the facts that ecological constraints influence nursing frequency, length of time until weaning and the composition of milk, there is considerable similarity in the anatomy and physiology of milk production and delivery across mammalian species. Here we provide an overview of cross species variation in nursing patterns and milk composition as well as the mechanisms underlying mammary gland development, milk production and letdown. Not all women breastfeed their infants, thus in later sections we review studies of factors that facilitate or impede the initiation and duration of breastfeeding. The results of these investigations suggest that the decisions to initiate and maintain breastfeeding are influenced by an array of personal, social and biological factors. Finally, studies comparing the development of breastfed and formula fed infants as well as those investigating associations between breastfeeding, maternal health and mother/infant interaction are reviewed. Leading health agencies including the World Health Organization and CDC advocate breastfeeding for at least the first 6months postpartum. To achieve these rates will require not only institutional support but also a focus on individual mother/infant dyads and their experience.

Social inequalities in malaria knowledge, prevention and prevalence among children under 5 years old and women aged 15-49 in Madagascar

BACKGROUND

Approximately 15 % of all deaths in Africa among children under five years old are due to malaria, a preventable and treatable disease. A prevailing sociological theory holds that resources (including knowledge, money, power, prestige, or beneficial social connections) are particularly relevant when diseases are susceptible to effective prevention. This study examines the role of socioeconomic inequalities by broadly predicting malaria knowledge and use of preventive technology among women aged 15-49, and malaria among children aged 6-59 months in Madagascar.

METHODS

Data came from women aged 15-49 years (N = 8279) interviewed by Madagascar's 2011/2013 Malaria Indicator Studies, and their children aged under five years (N = 7644). Because geographic location may be associated with socioeconomic factors and exposure to malaria, multilevel models were used to account for unobserved geographic and administrative variation. Models also account for observed social, economic, demographic, and seasonal factors.

RESULTS

Prevalence among children four years old and younger was 7.8 %. Results showed that both mother's education and household wealth strongly influence knowledge about and efforts to prevent and treat malaria. Analyses also revealed that the prevalence of malaria among children aged 6-59 months was determined by household wealth (richest vs poorest: OR = 0.25, 95 % CI [0.10, 0.64]) and maternal education (secondary vs none: OR = 0.51, 95 % CI [0.28, 0.95]).

CONCLUSIONS

Malaria may be subject to socio-economic forces arising from a broad set of behavioural and geographic determinants, even after adjusting for geographic risk factors and seasonality. Nearly 21 % of the sample lacked primary schooling. To improve malaria reduction efforts, broad-based interventions may need to attack inequalities to ensure that knowledge, prevention and treatment are improved among those who are most vulnerable.

Socioeconomic differences in childhood length/height trajectories in a middle-income country: a cohort study

BACKGROUND

Socioeconomic disadvantage is associated with shorter adult stature. Few studies have examined socioeconomic differences in stature from birth to childhood and the mechanisms involved, particularly in middle-income former Soviet settings.

METHODS

The sample included 12,463 Belarusian children (73% of the original cohort) born in 1996-1997, with up to 14 stature measurements from birth to 7 years. Linear spline multi-level models with 3 knots at 3, 12 and 34 months were used to analyse birth length and growth velocity during four age-periods by parental educational achievement (up to secondary school, advanced secondary/partial university, completed university) and occupation (manual, non-manual).

RESULTS

Girls born to the most (versus least) educated mothers were 0.43 cm (95% confidence interval (CI): 0.28, 0.58) longer at birth; for boys, the corresponding difference was 0.30 cm (95% CI: 0.15, 0.46). Similarly, children of the most educated mothers grew faster from birth-3 months and 12-34 months (p-values for trend ≤ 0.08), such that, by age 7 years, girls with the most (versus least) educated mothers were 1.92 cm (95% CI: 1.47, 2.36) taller; after controlling for urban/rural and East/West area of residence, this difference remained at 1.86 cm (95% CI: 1.42, 2.31), but after additionally controlling for mid-parental height, attenuated to 1.10 cm (95% CI: 0.69, 1.52). Among boys, these differences were 1.95 cm (95% CI: 1.53, 2.37), 1.89 cm (95% CI: 1.47, 2.31) and 1.16 cm (95% CI: 0.77, 1.55), respectively. Additionally controlling for breastfeeding, maternal smoking and older siblings did not substantively alter these findings. There was no evidence that the association of maternal educational attainment with growth differed in girls compared to boys (p for interaction = 0.45). Results were similar for those born to the most (versus least) educated fathers, or who had a parent with a non-manual (versus manual) occupation.

CONCLUSIONS

In Belarus, a middle-income former Soviet country, socioeconomic differences in offspring growth commence in the pre-natal period and generate up to approximately 2 cm difference in height at age 7 years. These associations are partly explained by genetic or other factors influencing parental stature.

TRIAL REGISTRATION

Current Controlled Trials: NCT01352247 assigned 9 Sept 2005; ClinicalTrials.gov. Identifier: NCT01561612 received 20 Mar 2012.

Have we left some behind? Trends in socio-economic inequalities in breastfeeding initiation: a population-based epidemiological surveillance study

OBJECTIVES

Breastfeeding is associated with improved health. Surveillance data show that breastfeeding initiation rates have increased; however, limited work has examined trends in socio-economic inequalities in initiation. The study's research question was whether socio-economic inequalities in breastfeeding initiation have changed over the past 20 years.

METHODS

This population-based study is a project within PATHS Equity for Children. Analyses used hospital discharge data for Manitoba mother-infant dyads with live births, 1988-2011 (n=316,027). Income quintiles were created, each with ~20% of dyads. Three-year, overall and by-quintile breastfeeding initiation rates were estimated for Manitoba and two hospitals. Age-adjusted rates were estimated for Manitoba. Rates were modelled using generalized linear models. Three measures, rate ratios (RRs), rate differences (RDs) and concentration indices, assessed inequality at each time point. We also compared concentration indices with Gini coefficients to assess breastfeeding inequality vis-à-vis income inequality. Trend analyses tested for changes over time.

RESULTS

Manitoba and Hospital A initiation rates increased; Hospital B rates did not change. Significant inequalities existed in nearly every period, across all three measures: RRs, RDs and concentration indices. RRs and concentration indices suggested little to no change in inequality from 1988 to 2011. RDs for Manitoba (comparing initiation in the highest to lowest income quintiles) did not change significantly over time. RDs decreased for Hospital A, suggesting decreasing socio-economic inequalities in breastfeeding; RDs increased for Hospital B. Income inequality increased significantly in Manitoba during the study period.

CONCLUSIONS

Overall breastfeeding initiation rates can improve while inequality persists or worsens.