Increasing mortality gap for patients diagnosed with schizophrenia over the last three decades--a Danish nationwide study from 1980 to 2010

Abstract

Objective: The objective of this study is to describe secular trends in the average age of death in patients with schizophrenia and to compare these with the general population.

Methods: This is a longitudinal linkage study from 1 January 1980 to 31 December 2010 using the Danish Psychiatric Research Register and the Danish Cause of Death Register. Data were analyzed using descriptive statistics and survival analysis.

Results: The average age of death in the schizophrenia population (62.2 years; 95% CI, 61.9-62.5) was lower compared to the general population (73.4 years; 95% CI, 73.4-73.4), P<0.001. In the general population we found, for men, an average increase in the age of death of 0.28 years (95% CI, 0.27-0.28) per calendar year, and for women an increase in age of death of 0.31 years (95% CI, 0.31-0.32) per calendar year (both P<0.001). In contrast, age of death decreased in the schizophrenia population: the change in average age of death for males was 0.04 years (95% CI, -0.09 to 0.00) per calendar year (P<0.05), and the comparable estimate for females was -0.05 years (95% CI, -0.09 to 0.01) per calendar year (P<0.05). A similar pattern existed after acts of self-harm as cause of death were excluded from the analyses. Patients diagnosed with schizophrenia had an increased mortality rate compared with the general population (hazard ratio, 2.05; 95% CI, 2.01-2.09).

Conclusions: On average, patients with schizophrenia die younger than the general population, independent of intentional self-harm as cause of death.