Optimism and physical health: a meta-analytic review.

BACKGROUND Prior research links optimism to physical health, but the strength of the association has not been systematically evaluated. PURPOSE The purpose of this study is to conduct a meta-analytic review to determine the strength of the association between optimism and physical health. METHODS The findings from 83 studies, with 108 effect sizes (ESs), were included in the analyses, using random-effects models. RESULTS Overall, the mean ES characterizing the relationship between optimism and physical health outcomes was 0.17, p < .001. ESs were larger for studies using subjective (versus objective) measures of physical health. Subsidiary analyses were also conducted grouping studies into those that focused solely on mortality, survival, cardiovascular outcomes, physiological markers (including immune function), immune function only, cancer outcomes, outcomes related to pregnancy, physical symptoms, or pain. In each case, optimism was a significant predictor of health outcomes or markers, all p < .001. CONCLUSIONS Optimism is a significant predictor of positive physical health outcomes.