Longitudinal bidirectional link between socioeconomic position and health: a national panel survey analysis.

BACKGROUND: Health inequities can stem from socioeconomic position (SEP) leading to poor health (social causation) or poor health resulting in lower SEP (health selection). We aimed to examine the longitudinal bidirectional SEP-health associations and identify inequity risk factors. METHODS: Longitudinal Household Israeli Panel survey participants (waves 1-4), age ≥25 years, were included (N=11 461; median follow-up=3 years). Health rated on a 4-point scale was dichotomised as excellent/good and fair/poor. Predictors included SEP parameters (education, income, employment), immigration, language proficiency and population group. Mixed models accounting for survey method and household ties were used. RESULTS: Examining social causation, male sex (adjusted OR 1.4; 95% CI 1.1 to 1.8), being unmarried, Arab minority (OR 2.4; 95% CI 1.6 to 3.7, vs Jewish), immigration (OR 2.5; 95% CI 1.5 to 4.2, reference=native) and less than complete language proficiency (OR 2.22; 95% CI 1.50 to 3.28) were associated with fair/poor health. Higher education and income were protective, with 60% lower odds of subsequently reporting fair/poor health and 50% lower disability likelihood. Accounting for baseline health, higher education and income were associated with lower likelihood of health deterioration, while Arab minority, immigration and limited language proficiency were associated with higher likelihood. Regarding health selection, longitudinal income was lower among participants reporting poor baseline health (85%; 95% CI 73% to 100%, reference=excellent), disability (94%; 95% CI 88% to 100%), limited language proficiency (86%; 95% CI 81% to 91%, reference=full/excellent), being single (91%; 95% CI 87% to 95%, reference=married), or Arab (88%; 95% CI 83% to 92%, reference=Jews/other). CONCLUSION: Policy aimed at reducing health inequity should address both social causation (language, cultural, economic and social barriers to good health) and health selection (protecting income during illness and disability).