Excess mortality and life-years lost in people with bipolar disorder: an 11-year population-based cohort study

Abstract

Aims Bipolar disorder is associated with premature mortality, but evidence is mostly derived from Western countries. There has been no research evaluating shortened lifespan in bipolar disorder using life-years lost (LYLs), which is a recently developed mortality metric taking into account illness onset for life expectancy estimation. The current study aimed to examine the extent of premature mortality in bipolar disorder patients relative to the general population in Hong Kong (HK) in terms of standardised mortality ratio (SMR) and excess LYLs, and changes of mortality rate over time. Methods This population-based cohort study investigated excess mortality in 12 556 bipolar disorder patients between 2008 and 2018, by estimating all-cause and cause-specific SMRs, and LYLs. Trends in annual SMRs over the 11-year study period were assessed. Study data were retrieved from a territory-wide medical-record database of HK public healthcare services. Results Patients had higher all-cause [SMR: 2.60 (95% CI: 2.45–2.76)], natural-cause [SMR: 1.90 (95% CI: 1.76–2.05)] and unnatural-cause [SMR: 8.63 (95% CI: 7.34–10.03)] mortality rates than the general population. Respiratory diseases, cardiovascular diseases and cancers accounted for the majority of deaths. Men and women with bipolar disorder had 6.78 (95% CI: 6.00–7.84) years and 7.35 (95% CI: 6.75–8.06) years of excess LYLs, respectively. The overall mortality gap remained similar over time, albeit slightly improved in men with bipolar disorder. Conclusions Bipolar disorder is associated with increased premature mortality and substantially reduced lifespan in a predominantly Chinese population, with excess deaths mainly attributed to natural causes. Persistent mortality gap underscores an urgent need for targeted interventions to improve physical health of patients with bipolar disorder.

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

“…We also found a reduced YPLL of around 5 years across the study periods in patients with bipolar disorder. This seems to be contrary to the findings of most previous individual studies that assessed SMR (primarily on an annual basis) for bipolar disorder and indicated persistent 3,5,7 or even a widening mortality gap 8–10 in recent decades. However, our analysis comparing life-expectancy/YPLL estimates of three discrete study periods might be limited by the fact that these periods were categorised according to the middle year of cohort data collection per study irrespective of the length of follow-up and only a small number of studies were included in each of the three study periods.…”

“…1,2 People with bipolar disorder exhibit markedly increased risk of premature death, with an approximately two to three times higher mortality rate relative to the general population. [3][4][5] Natural causes, particularly cardiovascular diseases, respiratory diseases and cancers, are a major contributor to excess mortality associated with bipolar disorder. [3][4][5][6] Literature also consistently has found that patients with bipolar disorder have a greatly elevated rate of unnatural deaths, especially suicide, compared with the general population.…”

“…[3][4][5] Natural causes, particularly cardiovascular diseases, respiratory diseases and cancers, are a major contributor to excess mortality associated with bipolar disorder. [3][4][5][6] Literature also consistently has found that patients with bipolar disorder have a greatly elevated rate of unnatural deaths, especially suicide, compared with the general population. [3][4][5] Such mortality gap has persisted 3,5,7 or even widened [8][9][10] in recent decades despite an overall increase in life expectancy in the general population as a result of healthcare improvements.…”

“…3–6 Literature also consistently has found that patients with bipolar disorder have a greatly elevated rate of unnatural deaths, especially suicide, compared with the general population. 3–5 Such mortality gap has persisted 3,5,7 or even widened 8–10 in recent decades despite an overall increase in life expectancy in the general population as a result of healthcare improvements. This indicates an urgent unmet need to address physical health inequalities experienced by patients with bipolar disorder.…”

Comparison of years of life lost to 1,565 suicides versus 10,650 COVID-19 deaths in 2020 in Sweden: four times more years of life lost per suicide than per COVID-19 death

“…Between country comparisons of YLL can be informative but the calculation of disease specific YLL can be prone to country specific differences in health care system and resources, and quality of cause of death statistics, as well as to diagnostic procedures and testing as can be seen in between country comparisons of YLL to COVID-19 (16). Without competing risk of suicide persons with psychiatric disease still have a shorter life expectancy (14,17). Similarly, YLL to COVID-19 is mostly attributable to the fragile comorbid old population (18).…”