All-cause mortality in a nationwide cohort of childhood-onset diabetes in Norway 1973–2013

Abstract

Aims/hypothesis: The aim of this study was to assess the association between all-cause mortality and sex, age at diagnosis and year of diagnosis in Norwegian patients with childhood-onset diabetes. Methods: The study was based on the nationwide, population-based Norwegian Childhood Diabetes Registry, which includes all newly diagnosed cases of childhood-onset diabetes at age 0–14 years in 1973–1982 and 1989–2012 (n = 7,884). Patients were followed until date of death, emigration or 30 September 2013. Results: Among the 7,884 patients, representing 132,420 person-years, 249 (3.2%) died during a mean follow-up of 16.8 (range 0.0–40.7) years. The standardised mortality ratio (SMR) for the total cohort was 3.6 (95% CI 3.1, 4.0), increasing by attained age. Absolute mortality was significantly lower in females than in males (HR 0.50 [95% CI 0.38, 0.65]), although the SMRs were similar. Cox regression analysis showed a significant decrease in mortality of 49% (HR 0.51 [95% CI 0.28, 0.93]) for those diagnosed in 1999–2012 compared with those diagnosed in 1973–1982 (p = 0.03). Conclusions/interpretation: In spite of improved diabetes care, mortality is still three to four times higher in those with childhood-onset diabetes compared with the general population in Norway. However, absolute mortality has declined among children diagnosed most recently (1999–2012) compared with those diagnosed in the earliest period (1973–1982).