Association of depression screening in cardiometabolic disease with future vascular events and mortality: a cohort study

Abstract

BackgroundRoutine screening for depression in patients with cardiometabolic disease is advocated but its benefits remain unclear. We examined the association between such screening in a large UK cohort of patients with cardiometabolic diseases and all-cause mortality and vascular events at 4 years. MethodsPatients in Greater Glasgow with one of three cardiometabolic diseases—coronary heart disease, diabetes, or stroke—underwent screening for depression with the Hospital Anxiety and Depression Scale (HADS-D). The health board offered monetary incentives for depression screening to primary care practitioners, and people with positive depression screens were treated (psychological or pharmacological) according to national guidelines. 125 143 patients with at least one of the diseases were listed on primary care registers during 12 months' observation in 2008–09. 10 670 (8·5%) receiving treatment for depression were exempt from screening. HADS-D was recorded for 35 537 patients (31·1% of eligible); the remaining 78 936 (68·9%) were not screened. We studied all-cause mortality and vascular events (using International Classification of Diseases 10 codes for myocardial infarction and stroke) by linking 124 414 patients (99·4%) on primary care registers to hospital discharge and mortality records for 4 years from April, 2009, and used Cox proportional hazards for survival analysis. FindingsMean age for the screened and unscreened population was 69 years (SD 11·9) and 67 years (14·3), respectively; 58% (20 658) of the screened population were men and 65·3% (22 726) belonged to a deprived socioeconomic group, compared with 54·2 % (42 727) and 67·4% (51 686), respectively, in the unscreened population. 4989 (6·3%) of 789 366 of the unscreened population were started on new antidepressants during the observation period compared with 1268 (3·5%) of 35 537 of the screened population and 572 of 7080 (8·02%) of those HADS-D positive. The screened population had lower all-cause mortality and vascular events than the unscreened population (hazard ratio 0·74, 95% CI 0·72–0·77, p<0·0001 vs 0·69, 0·67–0·72, p<0·0001) at 4 years. Results remained significant after adjusting for age, sex, socioeconomic status, and comorbidity. InterpretationScreening for depression was associated with a reduction in all-cause mortality and vascular events in patients with cardiometabolic diseases. The uptake of screening was poor for unknown reasons. The possibility of reverse causality and the possible confounding effect of disease severity are important limitations. Further research to determine reproducibility and explore underlying mechanisms is merited. FundingThe study was funded by BUPA Foundation. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the abstract.