Life expectancy and years of potential life lost in bipolar disorder: systematic review and meta-analysis

Background There is increasing research examining excess mortality in people with bipolar disorder using life expectancy and related measures, which quantify the disease impact on survival. However, there has been no meta-analysis to date summarising existing data on life expectancy in those with bipolar disorder. Aims To systematically review and quantitatively synthesise estimates of life expectancy and years of potential life lost (YPLL) in people with bipolar disorder. Method We searched Embase, Medline, PsycINFO and Web of Science databases up to 31 March 2021. We generated pooled life expectancy using random-effects models, and derived YPLL summary estimate by calculating averaged values weighted by sample size of individual studies. Subgroup analyses were conducted for gender, geographical region, study period, a given age (set-age) for lifespan estimation and causes of death. The study was registered with PROSPERO (CRD42021241705). Results Eleven and 13 studies were included in the review for life expectancy (n = 96 601) and YPLL (n = 128 989), respectively. Pooled life expectancy was 66.88 years (95% CI 64.47-69.28; I-2 = 99.9%, P < 0.001), was higher in women than men (70.51 (95% CI 68.61-72.41) v. 64.59 (95% CI 61.16-68.03); z = 2.00, P = 0.003) and was lowest in Africa. Weighted average YPLL was 12.89 years (95% CI 12.72-13.07), and was greatest in Africa. More YPLL was observed when lifespan was estimated at birth than at other set-age. YPLLs attributable to natural and unnatural deaths were 5.94 years (95% CI 5.81-6.07) and 5.69 years (95% CI 5.59-5.79), respectively. Conclusions Bipolar disorder is associated with substantially shortened life expectancy. Implementation of multilevel, targeted interventions is urgently needed to reduce this mortality gap.