Background Giant cell arteritis (GCA) is the most common systemic vasculitis in patients aged ≥50 years. Few studies have evaluated the economic impact of this condition and have been limited to inpatient-only data sources. Although the majority of healthcare for patients with GCA is provided as an outpatient, utilization and costs from this healthcare sector is largely unknown.
Objectives To determine the health care utilization and direct medical cost of GCA in a population-based cohort.
Methods This study utilized a retrospective, population-based cohort of patients diagnosed with GCA, as defined by 1990 ACR criteria, in 1982–2009 and a reference cohort of patients without GCA matched on age, sex, and calendar year from the same population. Standardized cost data (inflation-adjusted to 2014 dollars) for 1987–2014 and outpatient utilization data for 1995–2014 were obtained from the Mayo Clinic Cost Data Warehouse and analyzed from one year before and up to five years after the GCA diagnosis/index date. Utilization and costs were compared between GCA and non-GCA cohorts using signed rank two-tailed paired analyses.
Results The GCA cohort consisted of 147 patients (118 female, 29 male) with a mean (±SD) age of 77.2 (±8.2). The non-GCA cohort comprised 147 patients with a mean (±SD) age of 76.9 (±8.5) years.
During the year preceding diagnosis, excess healthcare cost related to GCA was only significantly increased in the month immediately preceding GCA diagnosis [mean (±SD) excess cost $1127 (±5154)]. Following diagnosis, significant annual excess outpatient cost was observed for patients with GCA in each of the first four years [mean excess cost (±SD): 0–1 yrs $1307 (±15581), p<0.001; 1–2yrs $908 (±5917), p=0.009; 2–3 yrs $1324 (±4648), p=0.007; 3–4 yrs $609 (±4596), p=0.04] but was similar between GCA and non-GCA subjects in the 5th year. There were no significant differences in inpatient costs between GCA and non-GCA subjects.
Patients with GCA had higher utilization of laboratory visit days annually for each of the first 3 years following diagnosis, as well as increased outpatient physician visits and combined radiology for years 0–1, 1–2, and 3–4 years (figure). Ophthalmologic procedures/surgery were increased for years 0–1, 1–2, and 4–5. Emergency medicine visits, musculoskeletal and cardiovascular procedures/surgery were similar between GCA and non-GCA groups throughout the study period.
Conclusions Direct medical costs were increased in the month preceding and outpatient costs were increased in the first 4 years following GCA diagnosis and then return to levels similar to non-GCA subjects. A higher utilization of outpatient physician, laboratory and radiology visits, as well as ophthalmologic procedures among these patients accounts for the observed increased cost of care.
Disclosure of Interest None declared