To explore mortality rates and causes of death in juvenile idiopathic arthritis (JIA) patients in Finland compared with the general population.
All incident patients with JIA (age <16 years at the index day) during 2000-2014 were collected from the nationwide register maintained by the Social Insurance Institution of Finland and The National Population Registry identified three age-, sex- and residence-matched controls for each case. They were followed up together until 31st Dec 2015.
Altogether 4,180 JIA patients (62% females) were identified. Mean age at diagnosis was 8.3 years. The average follow-up time was 6.6 years (IQR 3.1-10.5). The patients were compared with 12,511 controls. During 28,941 follow-up years, 11 JIA patients (6 females, 5 males) and 23 controls (12 females, 11 males) died. The mean age at death was 20.3 (range: 11-30) in JIA patients and 23.1 (range: 9-29) years in the control group, (p=0.17). Cumulative mortality in JIA was 0.6% (95% Cl 0.3-1.2) compared to 0.6% (95% Cl 0.4-1.0) in the controls; (hazard ratio 1.44, 95% Cl 0.70-2.95). Accidents were the most common (54%) cause of death in JIA, whereas suicide (39%) in the controls. Substance abuse and depression contributed more to deaths in the controls (39%) than in the JIA patients (10%), (p=0.053).
The mortality rate was not elevated in patients with juvenile idiopathic arthritis.