Increased mortality for individuals with Giant Cell Arteritis: a population-based study

Background — Reports of mortality risks among individuals with GCA have been mixed. Our aim was to evaluate all-cause mortality among individuals with GCA relative to the general population over time.

Methods — We performed a population-based study in Ontario, Canada, using health administrative data. We studied a cohort of 22,677 GCA patients aged ≥50 years identified using a validated case definition (with 81% positive predictive value, 100% specificity). General population comparators were residents aged ≥50 years without GCA. Deaths were ascertained from vital statistics. Annual crude, age/sex-standardized and age- and sex-specific all-cause mortality rates were determined for individuals with and without GCA between 2000 and 2018. Standardized mortality ratios (SMRs) were estimated.

Results — Age- and sex-standardized mortality rates were significantly higher for GCA patients than comparators, and trending to increase over time with 50.0 (95% confidence interval (CI) 34.0, 71.1) deaths per 1000 GCA patients in 2000 and 57.6 (95% CI 50.8, 65.2) deaths per 1000 in 2018, whereas mortality rates in the general population significantly declined over time. The annual SMRs for GCA patients generally increased over time with the lowest SMR occurring in 2002 (1.22; 95% CI 1.03, 1.40) and the highest in 2018 (1.92; 95% CI 1.81, 2.03). GCA mortality rates were more elevated for males than females.

Conclusion — Over a 19-year period, mortality rates were increased among GCA patients relative to the general population and more premature deaths were occurring in younger age groups. The relative excess mortality for GCA patients did not improve over time.