Importance: Optimism and pessimism can be easily measured and are potentially modifiable mindsets that may be associated with cardiovascular risk and all-cause mortality.
Objective: To conduct a meta-analysis and systematic review of the association between optimism and risk for future cardiovascular events and all-cause mortality.
Data sources and study selection: PubMed, Scopus, and PsycINFO electronic databases were systematically searched from inception through July 2, 2019, to identify all cohort studies investigating the association between optimism and pessimism and cardiovascular events and/or all-cause mortality by using the following Medical Subject Heading terms: optimism, optimistic explanatory style, pessimism, outcomes, endpoint, mortality, death, cardiovascular events, stroke, coronary artery disease, coronary heart disease, ischemic heart disease, and cardiovascular disease.
Data extraction and synthesis: Data were screened and extracted independently by 2 investigators (A.R. and C.B.). Adjusted effect estimates were used, and pooled analysis was performed using the Hartung-Knapp-Sidik-Jonkman random-effects model. Sensitivity and subgroup analyses were performed to assess the robustness of the findings. The Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline was followed.
Main outcomes and measures: Cardiovascular events included a composite of fatal cardiovascular mortality, nonfatal myocardial infarction, stroke, and/or new-onset angina. All-cause mortality was assessed as a separate outcome.
Results: The search yielded 15 studies comprising 229 391 participants of which 10 studies reported data on cardiovascular events and 9 studies reported data on all-cause mortality. The mean follow-up period was 13.8 years (range, 2-40 years). On pooled analysis, optimism was significantly associated with a decreased risk of cardiovascular events (relative risk, 0.65; 95% CI, 0.51-0.78; P < .001), with high heterogeneity in the analysis (I2 = 87.4%). Similarly, optimism was significantly associated with a lower risk of all-cause mortality (relative risk, 0.86; 95% CI, 0.80-0.92; P < .001), with moderate heterogeneity (I2 = 73.2%). Subgroup analyses by methods for assessment, follow-up duration, sex, and adjustment for depression and other potential confounders yielded similar results.
Conclusions and relevance: The findings suggest that optimism is associated with a lower risk of cardiovascular events and all-cause mortality. Future studies should seek to better define the biobehavioral mechanisms underlying this association and evaluate the potential benefit of interventions designed to promote optimism or reduce pessimism.