The effect of comorbid depression on the use of unscheduled hospital care by people with a long term condition: A retrospective observational study

Background The prevalence of long-term conditions (LTCs) and multiple-morbidity is increasing. Depression prevalence increases with the number of LTCs. Self-management of LTCs improves outcomes, but depression impacts on self-management. Unscheduled hospital care may be a proxy for failure of planned care to support successful self-management. Methods Retrospective observational study based on routine NHS datasets covering 19 LTCs. Prevalence of LTCs and depression was identified in all primary care registered adults in one English city (n = 469,368). Chi squared was used for hypothesis testing, and logistic regression to determine the influence of depression and LTC(s) on the use of unscheduled hospital care. Results At least one LTC was identified in 220,010 (46.9%) adults; 75,107 (16.0%) had depression; and 38,232 (8.1%) had LTC plus comorbid depression. A significantly greater proportion of individuals with LTC and comorbid depression had ≥ 1 unscheduled event over 12 months (31.5%) compared to individuals with LTC(s) only (24.0%), X2(1) = 883.860, p < .001.

The logistic regression model explained 4.4% of the variation in unscheduled care use. Individuals with depression plus ≥ 1 LTC were 1.59 times more likely to use unscheduled hospital care than individuals with LTC only (p < .001), after controlling for deprivation, age and number of LTCs. Limitations Cross-sectional data precluded identification of the direction of influence between LTCs and depression. Only 19 major LTCs were studied, so overall LTC prevalence will be under-represented, and other significant predictors may be omitted. Conclusion In people with a LTC, comorbidity with depression increases use of unscheduled hospital care.