Social inequalities in mortality in older women cannot be explained by biological and health behavioural factors - results from a Norwegian health survey (the HUNT Study)

Aims: To assess mortality inequalities related to education, employment and marital status in older women, and whether educational and employment inequalities can be explained by biological, health behavioural or marital factors. Methods: Data, collected by questionnaires and medical examinations, on 5607 Norwegian women aged >= 70 participating in the population-based Nord-Trondelag health study in 1995-97, were linked with information from the Death Registry at Statistics Norway at 31.12.2004. Cox regression model was used to estimate hazard ratios (HR) of all-cause and cardiovascular mortality related to educational level and previous employment, and to marital status. Results: Low level of education and never having been in paid work were significantly associated with elevated all-cause mortality. The associations remained significant upon adjustments for age, marital status, biological (systolic blood pressure, body mass index, total cholesterol) and health behavioural (smoking, physical activities) factors. Differences in cardiovascular mortality were related to low level of education and never having been in paid work, though the significant age-adjusted associations only remained significant for education upon adjustments for age, marital, biological and behavioural factors. A raised risk in cardiovascular mortality was found among women previously holding manual jobs (HR1.23, 95% CI 0.99-1.53). The graded association between education, employment and mortality showed a significant trend, except from the occupation gradient in cardiovascular mortality. Widowed and divorced women had an age-adjusted significantly raised all-cause and significant cardiovascular mortality risk compared with married women. Conclusions: The socioeconomic and marital differences in mortality in older women could not be explained by biological and behavioural factors, and remains a public health issue.