Reconsidering upstream approaches to improving population health

Racial and socioeconomic disparities in health outcomes have been well documented. 1 Blumenshine P Egerter S Barclay CJ Cubbin C Braveman PA Socioeconomic disparities in adverse birth outcomes: a systematic review. Am J Prev Med. 2010; 39: 263-272 Summary Full Text Full Text PDF PubMed Scopus (477) Google Scholar , 2 Matoba N Collins Jr, JW Racial disparity in infant mortality. Semin Perinatol. 2017; 41: 354-359 Crossref PubMed Scopus (43) Google Scholar Although overall global rates of poor birth outcomes have decreased, decades of research and interventions have not eliminated disparities. However, much intervention research has focused on individual-level risk factors and groups at high risk. In The Lancet, Jennifer Jardine and colleagues 3 Jardine J Walker K Gurol-Urganci I et al. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort study. Lancet. 2021; (published online Nov 1.)https://doi.org/10.1016/S0140-6736(21)01595-6 Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar report on population attributable fractions, which indicate the proportion of a particular outcome that would be removed if a risk factor did not exist or was more similar to a reference population. The use of population attributable fractions is an important contribution because it demonstrates the excess risk of poor outcomes that can be attributed to population-level factors. The authors provide a potential roadmap for future interventions, emphasising the role of widespread health promotion in improving population-level health metrics over targeted, individual-level interventions that have less population impact. 4 Rose G Sick individuals and sick populations. Int J Epidemiol. 1985; 14: 32-38 Crossref PubMed Scopus (2188) Google Scholar This study 3 Jardine J Walker K Gurol-Urganci I et al. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort study. Lancet. 2021; (published online Nov 1.)https://doi.org/10.1016/S0140-6736(21)01595-6 Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar included 1·16 million singleton births in England, which represented 94% of England's births obtained from administrative hospital data linked to the National Maternity and Perinatal Audit between 2015 and 2017. The authors report that 24% of stillbirths, 19% of preterm births, and 31% of fetal growth restriction could be attributed to socioeconomic inequality. The women included in the sample were 77·2% White, 11·9% south Asian, 4·9% Black, 1·8% mixed ethnicity, and 4·2% other ethnicity. Perhaps most striking were the authors’ findings on the intersection of race and socioeconomic disadvantage, describing that more than half of stillbirths, a third of preterm births, and nearly two-thirds of fetal growth restriction among south Asian and Black women could be eliminated if their risk factors were equal to the least socioeconomically deprived White women. The authors suggest that this finding supports a combination of population-based and risk-based approaches, but does not consider the inextricable link between ethnic background and socioeconomic deprivation. 5 Kane JB Miles G Yourkavitch J King K Neighborhood context and birth outcomes: going beyond neighborhood disadvantage, incorporating affluence. SSM Popul Health. 2017; 3: 699-712 Crossref PubMed Scopus (17) Google Scholar Additionally, the association between race or socioeconomic inequality and birth outcomes might vary because of factors like social support and experiences of racism and discrimination. In combination with the limitation of using an area-level index of deprivation, the authors acknowledge potential inaccuracies and bias in the population attributable fractions. 6 Mansournia MA Altman DG Population attributable fraction. BMJ. 2018; 360: k757 Crossref PubMed Scopus (114) Google Scholar They rightfully note that more detailed causal mediation analysis is a research priority. Moreover, because the definition of fetal growth restriction varies by the reference used, which itself varies by ethnic mix in the index population, 7 Grantz KL Fetal growth curves: is there a universal reference?. Obstet Gynecol Clin North Am. 2021; 48: 281-296 Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar interpretations of this outcome are unclear. Indeed, the authors may be capturing small-for-gestational age rather than fetal growth restriction, which may not indicate pathology. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort studyOur results indicate that socioeconomic and ethnic inequalities were responsible for a substantial proportion of stillbirths, preterm births, and births with FGR in England. The largest inequalities were seen in Black and South Asian women in the most socioeconomically deprived quintile. Prevention should target the entire population as well as specific minority ethnic groups at high risk of adverse pregnancy outcomes, to address risk factors and wider determinants of health. Full-Text PDF