Social deprivation and prognostic benefits of cardiac surgery: observational study of 44 902 patients from five hospitals over 10 years

Abstract

OBJECTIVE: To assess the effects of social deprivation on survival after cardiac surgery and to examine the influence of potentially modifiable risk factors. DESIGN: Analysis of prospectively collected data. Prognostic models used to examine the additional effect of social deprivation on the end points. SETTING: Birmingham and north west England. PARTICIPANTS: 44 902 adults undergoing cardiac surgery, 1997-2007. MAIN OUTCOME MEASURES: Social deprivation with census based 2001 Carstairs scores. All cause mortality in hospital and at mid-term follow-up. RESULTS: In hospital mortality for all cardiac procedures was 3.25% and mid-term follow-up (median 1887 days; range 1180-2725 days) mortality was 12.4%. Multivariable analysis identified social deprivation as an independent predictor of mid-term mortality (hazard ratio 1.024, 95% confidence interval 1.015 to 1.033; P<0.001). Smoking (P<0.001), body mass index (BMI, P<0.001), and diabetes (P<0.001) were associated with social deprivation. Smoking at time of surgery (1.294, 1.191 to 1.407, P<0.001) and diabetes (1.305, 1.217 to 1.399, P<0.001) were independent predictors of mid-term mortality. The relation between BMI and mid-term mortality was non-linear and risks were higher in the extremes of BMI (P<0.001). Adjustment for smoking, BMI, and diabetes reduced but did not eliminate the effects of social deprivation on mid-term mortality (1.017, 1.007 to 1.026, P<0.001). CONCLUSIONS: Smoking, extremes of BMI, and diabetes, which are potentially modifiable risk factors associated with social deprivation, are responsible for a significant reduction in survival after surgery, but even after adjustment for these variables social deprivation remains a significant independent predictor of increased risk of mortality.