Investigating equalisation of health inequalities during adolescence in four low-income and middle-income countries: an analysis of the Young Lives cohort study

OBJECTIVE: To investigate if socioeconomic gradients in health reduce during adolescence (the equalisation hypothesis) in four low-income and middle-income countries (LMIC). SETTING: Analysis of the Young Lives Study cohorts in Ethiopia, Peru, Vietnam and India. PARTICIPANTS: A total of 3395 participants (across the four cohorts) aged 6–10 years at enrolment and followed up for 11 years. OUTCOMES MEASURED: Change in income-related health inequalities from mid-childhood to late adolescence. Socioeconomic status was determined by wealth index quartile. The health indicators included were self-reported health, injuries in the previous 4 years, presence of long-term health problems, low mood, alcohol use, overweight/obesity, thinness and stunting. The relative risk of each adverse health outcome between highest and lowest wealth index quartile were compared across four waves of the study within each country. RESULTS: We found steep socioeconomic gradients across multiple health indicators in all four countries. Socioeconomic gradients remained similar across all waves of the study, with no significant decrease during adolescence. CONCLUSION: We found no consistent evidence of equalisation for income-related health inequalities in youth in these LMIC. Socioeconomic gradients for health in these cohorts appear to persist and be equally damaging across the early life course and during adolescence.