Introduction: Socio-economic inequalities in child health have been documented post-Medicare (1971) in Canada. Although it is assumed that the introduction of Medicare reduced these inequalities, comparable pre-Medicare data are lacking. Therefore we investigated infant mortality using income quintile analysis. We also explored potential explanatory variables reflecting pre-Medicare social conditions. Methods: Census division infant mortality data for 1950-52 and 1962-64 and corresponding income data were obtained. Statistics Canada definitions of low income were used to determine the percentage of low income families in each census division. For each study period, divisions were ranked by percentage of low income families and divided into income quintiles. Infant, neonatal and postneonatal mortality rates (IMR, NMR, PNMR) were determined for each quintile. Multiple regression analyses were performed with the following explanatory variables: percentage low income and average annual income(separate analyses); percentage of occupied dwellings with no installed bath facilities, no running water and no refrigeration facilities; and percentage having a TV and having a car. Results: 206 (1950-52) and 208(1962-64) census divisions from 8 provinces were included. Although infant mortality rates declined significantly between the two study periods, relative infant mortality did not change. The ratio Q5:Q1 (highest percentage low income vs lowest) was 1.62 in 1950-52 (95% CI 1.57-1.67) and 1.57 in 1962-64(95% CI 1.51-1.63). Multiple regression analyses showed that having a TV (IMR, PNMR), having a car (IMR,PNMR), and not having installed bath facilities(IMR,NMR,PNMR) were better predictors of infant mortality than income measures. Discussion: Infant mortality inequalities persisted after Medicare: a study of census metropolitan areas documented relative infant mortality of 1.97 in 1971 and 1.82 in 1986 (lowest compared to highest income quintile,Wilkins 1986). Our results suggest that improvements in access to medical care benefited children both in poor and wealthy areas of Canada. Alternatively, inequitable access may still exist. The limitations of medical care in reducing inequalities in health status are well known; social policy addressing the issue of child poverty may be required to achieve greater equity.
