Illiteracy, low educational status, and cardiovascular mortality in India

BACKGROUND: Influence of education, a marker of SES, on cardiovascular disease (CVD) mortality has not been evaluated in low-income countries. To determine influence of education on CVD mortality a cohort study was performed in India. METHODS: 148,173 individuals aged ≥ 35 years were recruited in Mumbai during 1991-1997 and followed to ascertain vital status during 1997-2003. Subjects were divided according to educational status into one of the five groups: illiterate, primary school (≦ 5 years of formal education), middle school (6-8 years), secondary school (9-10 years) and college (> 10 years). Multivariate analyses using Cox proportional hazard model was performed and hazard ratios (HRs) and 95% confidence intervals (CIs) determined. RESULTS: At average follow-up of 5.5 years (774,129 person-years) 13,261 deaths were observed. CVD was the major cause of death in all the five educational groups. Age adjusted all-cause mortality per 100,000 in illiterate to college going men respectively was 2154, 2149, 1793, 1543 and 1187 and CVD mortality was 471, 654, 618, 518 and 450; and in women all-cause mortality was 1444, 949, 896, 981 and 962 and CVD mortality was 429, 301, 267, 426 and 317 (p(trend )< 0.01). Compared with illiterate, age-adjusted HRs for CVD mortality in primary school to college going men were 1.36, 1.27, 1.01 and 0.88 (p(trend )< 0.05) and in women 0.69, 0.55, 1.04 and 0.74, respectively (p(trend )> 0.05). CONCLUSIONS: Inverse association of literacy status with all-cause mortality was observed in Indian men and women, while, for CVD mortality it was observed only in men.