Phase-Specific Healthcare Costs Associated With Giant Cell Arteritis in Ontario, Canada

To estimate the additional healthcare system costs associated with giant cell arteritis (GCA) in the 1-year prediagnosis and postdiagnosis periods and over long-term follow-up compared to individuals with similar demographics and comorbidities without GCA.

We performed a population-based study using health administrative data. Newly diagnosed cases of GCA (between 2002 and 2017 and aged ≥ 66 years) were identified using a validated algorithm and matched 1:6 to comparators using propensity scores. Follow-up data were accrued until death, outmigration, or March 31, 2020. The costs associated with care were determined across 3 phases: the year before the diagnosis of GCA, the year after, and ongoing costs thereafter in 2021 Canadian dollars (CAD).

The cohort consisted of 6730 cases of GCA and 40,380 matched non-GCA comparators. The average age was 77 (IQR 72-82) years and 68.2% were female. A diagnosis of GCA was associated with an increased cost of CAD $6619.4 (95% CI 5964.9-7274.0) per patient during the 1-year prediagnostic period, $12,150.3 (95% CI 11,233.1-13,067.6) per patient in the 1-year postdiagnostic phase, and $20,886.2 (95% CI 17,195.2-24,577.2) per patient during ongoing care for year 3 onward. Increased costs were driven by inpatient hospitalizations, physician services, hospital outpatient clinic services, and emergency department visits.

A diagnosis of GCA was associated with increased healthcare costs during all 3 phases of care. Given the substantial economic burden, strategies to reduce the healthcare utilization and costs associated with GCA are warranted.