Psychosocial and socioeconomic factors in the development of cardiovascular disease : a study of causality, mediation, international variation, and prediction in predominantly Eastern European settings

• Main Author: Tillmann, Taavi
• Published: University College London (University of London) 2018
• Subjects: 614.4
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763314

BACKGROUND: Psychosocial and socioeconomic factors have previously been associated with cardiovascular disease (CVD). I ask: 1) Are these associations causal? 2) Do their pathways overlap with one another? 3) Can they account for international differences in CVD? 4) Can they improve clinical risk prediction models? METHODS: Causality between education and coronary artery disease was investigated with Mendelian randomization analyses. For mediation and international differences, data on participants aged 45-69 years from the population-based HAPIEE cohort study were analysed using Cox regressions. A novel risk prediction model was derived from this data, and external validation was performed using data from the Estonian BioBank study. RESULTS: 1) Genetic predisposition towards longer education was associated with a reduction in coronary artery disease (Odds Ratio=0.67 [95% CI= 0.59 to 0.77], per extra 3.6 extra years of education), as well as large reductions in smoking. 2) In observational analyses, cardiovascular mortality was independently associated with unemployment, low material amenities, depression, being single, infrequent contacts with friends and relatives. These associations were of similar magnitude when comparing minimallyadjusted and fully-adjusted models. 3) International differences in CVD mortality between Russian & Central European cohorts remained unexplained after adjustment for conventional, psychosocial and socioeconomic risk factors. 4) Adding predominantly socioeconomic and psychosocial factors to risk prediction models improved their discrimination, clinical effectiveness, binary NRI and Net Benefit, in derivation and validation data. CONCLUSIONS: Education is probably a causal risk factor in the development of coronary heart disease. At least 6 socioeconomic/psychosocial factors appear to associate with CVD along pathways that may be relatively independent of one another and the conventional CVD risk factors. Uncovering their mechanisms may suggest novel avenues for intervention. While the causes of international differences in cardiovascular mortality remain unclear, socioeconomic and psychosocial factors substantially improved the performance of cardiovascular risk prediction.