Healthcare Use and Direct Cost of Giant Cell Arteritis: A Population-based Study

Objective. To determine the healthcare use and direct medical cost of giant cell arteritis (GCA) in a population-based cohort. Methods. A well-defined, retrospective population-based cohort of Olmsted County, Minnesota, USA, residents diagnosed with GCA from 1982-2009 was compared to a matched referent cohort from the same population. Standardized cost data (inflation-adjusted to 2014 US dollars) for 1987-2014 and outpatient use data for 1995-2014 were obtained. Use and costs were compared between cohorts through signed-rank paired tests, McNemar's tests, and quantile regression models. Results. Significant annual differences in outpatient costs were observed for patients with GCA in each of the first 4 years (median differences: $2085, $437, $382, $388, respectively). In adjusted analyses, median incremental cost attributed to GCA over a 5-year period was $4662. Compared with matched referent subjects, patients with GCA had higher use of laboratory visit-days annually for each of the first 3 years following incidence/index date, and increased outpatient physician visits for years 0-1, 1-2, and 3-4. Patients with GCA had significantly more radiology visit-days in years 0-1, 3-4, and 4-5, and more ophthalmologic procedures/surgery in years 0-1, 1-2, 2-3, and 4-5 compared to non-GCA. Emergency medicine visits, musculoskeletal, and cardiovascular procedures/surgery were similar between GCA and non-GCA groups throughout the study period. Conclusion. Direct medical outpatient costs were increased in the month preceding and in the first 4 years following GCA diagnosis. Higher use of outpatient physician, laboratory, and radiology visits, and ophthalmologic procedures among these patients accounts for the increased cost of care.