All-cause and cause-specific mortality in patients with depression in Scotland

Abstract

IntroductionPremature mortality in people with depression is well established. A better understanding of the causes of death and the relative risks of death from each cause may help identify factors that contribute to the health inequalities between people with and without depression.ObjectivesTo describe all-cause and cause-specific mortality of people with a hospital admission record for depression in Scotland, relative to the general population.MethodsWe used a linked population-based dataset of all psychiatric hospital admissions in Scotland to the national death dataset to identify 28,837 adults ≥18 years of age who had a hospital admission record of depression between 2000 and 2019. We obtained general population estimates and mortality data from the National Records of Scotland and quantified the relative difference in mortality by calculating the standardised mortality ratio (SMR), using indirect standardisation and stratifying by sex.ResultsDuring a median follow-up of 8.1 years, 7,931(27.5%) people who were hospitalised for depression died. Circulatory system diseases were the most common causes of death. Standardised all-cause mortality was more than three times higher than would be expected based on death rates in the general Scottish population. SMRs were similar in men and women for all-cause mortality and, in general, for cause-specific death (Table 1). The SMR for the suicide category was markedly higher in women than men, partly explained by the higher suicide mortality in males than females in the general population.Table 1All-cause and cause-specific mortality of people hospitalised for depression in Scotland 2000-19Observed deaths, n(All)Expected deaths, n(All)SMR (95% CI)(All)Observed deaths, n(Male)Expected deaths, n(Male)SMR (95% CI)(Male)Observed deaths, n(Female)Expected deaths, n(FemaleSMR (95% CI)(Female) All-cause7,93124273.3(3.2-3.3)361710523.4(3.3-3.5)431413753.1(3.0-3.2)Circulatory system diseases2,0208062.5(2.4-2.6)8863432.6(2.4-2.7)1,1344632.4(2.3-2.6)Neoplasms1,1536821.7(1.6-1.8)5343061.7(1.6-1.9)6193761.6(1.5-1.8)Respiratory system diseases1,1062923.8(3.6-4.0)4531124.0(3.7-4.4)6531803.6(3.3-3.9)Mental & behavioural disorders8351316.4(5.9-6.8)333526.4(5.7-7.2)502796.3(5.8-6.9)Accidents395695.7(5.2-6.3)224385.9(5.1-6.7)171315.5(4.7-6.3)Suicide, self-harm & injuries of undetermined Intent8055315.2(14.1-16.2)4853912.4(11.3-13.5)3201422.9(20.3-25.4)Other external cause2864.7(2.9-6.4)1635.3 (2.7- 7.9)1234.0(1.7-6.3)Other natural diseases1,5893884.1(3.9-4.3)6861594.3 (4.0-4.6)9032293.9(3.7-4.2)CI: Confidence interval; SMR: Standardised mortality ratioConclusionsPeople hospitalised for depression continue to have higher all-cause mortality than the general population in Scotland, with relative mortality varying by cause of death.Disclosure of InterestNone Declared