Dobloug GC, et al. – This population–based study highlighted the mortality in patients with idiopathic inflammatory myopathies (IIMs). Collected data represented that mortality was increased in patients with contemporary IIM. Within a year of diagnosis, the increased mortality was reported, which calls for extra vigilance during the first year of IIM diagnosis.

Methods

• With the aid of healthcare registers, patients diagnosed with IIM between 2002 and 2011 and general population comparators were selected.
• For follow–up, they were linked to the cause of death register.

Results

• 224 (31%) of the 716 patients with IIM and 870 (12%) of the 7100 general population died during follow–up.
• This corresponded to a mortality rate of 60/1000 person–years in IIM and 20/1000 person–years in the general population.
• The cumulative mortality at 1 year after diagnosis was 9% in IIM and 1% in the general population, and increased in both IIM and the general population with time.
• The overall hazard ratio (HR) 95%CI of death comparing IIM with the general population was 3.7 (3.2 to 4.4).
• When the authors stratified on time since diagnosis, they reported an increase in mortality already within the first year of diagnosis compared with the general population, HR 9.6 (95% CI 6.9 to 13.5).
• This HR then plateaued around 2 after >10 years with the disease, although the estimates were not statistically significant.
• The common causes of death were malignancies, diseases of the circulatory and respiratory system.