Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial

OBJECTIVE The study objective was to describe the effect of socioeconomic status (SES) on mortality among people with type 2 diabetes. RESEARCH DESIGN AND METHODS We used a population-based national electronic diabetes database for 35- to 84-year-olds in Scotland for 2001–2007 linked to mortality records. SES was derived from an area-based measure with Q5 and Q1 representing the most deprived and affluent quintiles, respectively. Poisson regression was used to estimate relative risks (RRs) for mortality among people with type 2 diabetes compared with the population without diabetes stratified by age (35–64 and 65–84 years), sex, duration of diabetes (<2 and =2 years), and SES. RESULTS Complete data were available for 210,994 eligible people (99.4%), and there were 33,842 deaths. Absolute mortality from all causes among people with type 2 diabetes increased with increasing age and socioeconomic deprivation and was higher for men than women. RR for mortality associated with type 2 diabetes was highest for women aged 35–64 years in Q1 with diabetes duration <2 years at 4.83 (95% CI 3.15–7.40) and lowest for men aged 65–84 years in Q5 with diabetes duration =2 years at 1.13 (1.03–1.24). CONCLUSIONS SES modifies the association between type 2 diabetes and mortality so that RR for mortality is lower among more deprived populations. Age, sex, and duration of diabetes also interact with type 2 diabetes to influence RR of mortality. Differences in prevalence of comorbidities may explain these findings