Determinants of health inequalities among adults in Korogocho informal settlement, Nairobi, Kenya

Abstract

Dearth of actionable evidence of the magnitude, determinants, and mediators of health inequalities in deprived communities has hampered efforts to eliminate invidious health inequalities. The objectives of this study, which set out to bridge the knowledge gap, were to assess the magnitude of health inequalities, identify the determinants of health inequalities, and determine which material, psychosocial, and behavioral factors mediate health inequalities in Korogocho, an informal settlement in Nairobi, capital city of Kenya. Eligible, consenting adults were selected from each of Korogocho informal settlement's nine villages, for this cross-sectional, field-based study, through multi-stage mixed cluster sampling. The independent variables comprised demographic, socioeconomic, and environmental determinants while the mediating variables were material, psychosocial, and behavioral factors. Differences in the prevalence of the dependent variables: self-rated health status and self-reported chronic health conditions, were the indicators of health inequalities. Health inequalities were measured in three dimensions: health disadvantage, health gap, and social health gradient using prevalence difference, odds ratio, and concentration curves respectively. Complementary qualitative data were collected from six focus group discussions and key informant interviews. The study population comprised 719 adults aged 25 to 59 years, mean age 34.20 ± 8.68 years with 188 (26.1%) males. Ngomongo village respondents had the highest prevalence of poor self-rated health status (44.3%) while Grogan B village respondents had the highest prevalence (29.7%) of self-reported chronic health conditions. Compared to Korogocho informal settlement, Ngomongo village (Odds ratio [OR], 2.22; 95% CI, 1.44 to 3.44; P = 0.0003) and Kisumu Ndogo village (OR, 1.76; 95% CI, 1.06 to 2.93; P = 0.029) respondents suffered significant health disadvantage. Varying magnitudes of health gaps and gradients were detected in the villages except in Highridge village where the magnitude of health inequalities was not statistically significant. Social health gradients were most marked within Gitathuru and Kisumu Ndogo villages but not across Korogocho informal settlement. From binary logistic regression, older age (45 to 59 years), female gender, lack of access to health care, and village of residence were the significant determinants of health inequalities. Significant mediators of health inequalities were alcohol intake, lack of voluntary physical exercise, having multiple, concurrent sexual partners, and unprotected sex. Mediators contributed between 10.5% and 14% in females and between 30.3% and 40.4% in males, to health inequalities. The qualitative interviewees attributed ill-health mainly, to environmental pollution, poor sanitation, and poverty. To conclude, despite mass deprivations and concentrated poverty, disaggregated data showed significant magnitudes of health inequalities within and across some villages of Korogocho informal settlement. Most of the identified determinants and mediators of health inequalities were socially constructed and therefore remediable. This study provides needed policy-relevant evidence, which is based on local priorities and should help stakeholders to target policies and design interventions such as social protection, gender mainstreaming, environmental regeneration, and health promotion to eliminate health inequalities and hence leverage aggregate population health. Future large scale, longitudinal studies that incorporate life-courses perspectives are recommended to further validate the findings of this study in other deprived communities in Africa and globally.