All-cause and cause-specific mortality in patients with giant cell arteritis: a nationwide, population-based cohort study

Objectives: To investigate whether GCA is associated with increased all-cause and cause-specific mortality.

Methods: A nationwide, population-based cohort study in Denmark using medical and administrative registries. GCA cases were defined as patients aged ≥50 years from 1996-2018 with a first-time discharge diagnosis of GCA and ≥3 prescriptions for prednisolone within 6 months following diagnosis. Each GCA patient was matched based on age, sex and calendar time to 10 persons without a history of GCA. Index date was the date for the third prednisolone prescription. We used a pseudo-observation approach to calculate all-cause and cause-specific mortality, adjusted risk differences (RDs) and relative risks (RRs).

Results: We included 9908 GCA patients and 98 204 persons from the general population. The median time for GCA patients to redeem the third prednisolone prescription was 74 days [interquartile range (IQR: 49-106)]. Among GCA patients, the overall mortality was 6.4% (95% CI: 5.9, 6.9) 1 year after index date and 45% (95% CI: 44, 47) after 10 years. Compared with the reference cohort, adjusted RDs and RRs of deaths in the GCA cohort were 2.2% (95% CI: 1.7, 2.7) and 1.49 (95% CI: 1.36, 1.64) after 1 year, and 2.1% (95% CI: 1.0, 3.3) and 1.03 (95% CI: 1.00, 1.05) 10 years after index date. GCA patients had a higher risk of death due to infectious, endocrine, cardiovascular and gastrointestinal diseases.

Conclusions: GCA is associated with increased all-cause mortality, particularly within the first year following the diagnosis. Cause-specific mortality indicates that mortality in GCA may in part be due to glucocorticoid-related complications.