Background/Purpose

Giant cell arteritis (GCA) is an inflammatory vasculitis preferentially affecting large and medium-sized arteries with an incidence of 1 to 30/100,000. High-dose oral corticosteroids (CS) are the mainstay of GCA therapy. We examined the risk of oral CS-related adverse events in a US commercially insured population.

Methods

This was a retrospective cohort study using MarketScan® during 2003-2012. We identified GCA patients who had at least 2 medical claims with a GCA diagnosis (International Classification of Diseases, 9^th Revision, Clinical Modification code 446.5), had at least 1 oral CS prescription fill within 6 months before or after the first GCA diagnosis, and were at least 50 years old. Patients were followed for at least 1 year until disenrollment or study end. We measured oral CS use in 3 ways: cumulative number of days, cumulative prednisone-equivalent exposure, and contemporaneous use (time from the date of interest to last oral CS use). We prospectively reviewed published literature to identify adverse events of interest known to be associated with oral CS use. Adverse events included cataracts, glaucoma, pneumonia, opportunistic infections, peptic ulcer disease, and bone-related conditions. We conducted Cox regression analyses to model oral CS use across time and the resultant risk of developing adverse events.

Results

The cohort contained 2,497 GCA patients with mean age 71 years, 71% women, and mean Charlson comorbidity index 1.5. Median initial oral CS dose in the cohort was 40 mg/day. Patients required a median 190 days to reduce this dose to ≤7.5 mg/day and received a median cumulative oral CS dose of 3,380 mg until this level was reached. They required a median 210 days to reach ≤5.0 mg/day and received a median 3,600 mg until this level was reached.

Patients with any adverse event were prescribed more days of oral CS (median 195 vs. 102.5 days) and received a higher cumulative prednisone-equivalent dose (median 3,400 vs. 2,145 mg) than those without an adverse event.

After adjusting for patient characteristics, each additional 1 gram increase in cumulative prednisone-equivalent exposure increased the hazard ratio of developing a first adverse event by 3% (p<.001).  Similar patterns of increase were observed for individual adverse events, as well as for adverse event risk regardless of the method used to measure oral CS use (Table). Each additional cumulative month of oral CS increased the hazard ratio for first adverse event by 1% (p=.003). For current oral CS users, the hazard ratio for first adverse event was 1.47 (p<.001) compared to non-users. 

TABLE

Risk of Developing Oral Corticosteroid-Related Adverse Events Based on Model of Oral Corticosteroid Use
Oral Corticosteroid Use Model	Hazard Ratio of First Adverse Event	Hazard Ratio of Osteoporosis	Hazard Ratio of Fracture	Hazard Ratio of Cataract	Hazard Ratio of Glaucoma	Hazard Ratio of Pneumonia	Hazard Ratio of Diabetes Mellitus
Each Additional Gram of Prednisone-Equivalent Exposure	1.03*	1.05*	1.04*	1.03*	1.05*	1.03*	1.05*
Each Additional Month of Oral Corticosteroid Use	1.01*	1.02*	1.01*	1.01	1.02*	1.01*	1.00
Current Oral Corticosteroid Use vs. No Use in 1 Year of Follow-Up	1.47*	2.28*	2.05*	1.39*	1.57	1.63*	1.51*
* p-value <.05

Conclusion

In a large cohort of GCA patients, high-dose oral CS use was near-universal. Patients were maintained on oral CS for a median 7 months before tapering to a daily dose of ≤5.0 mg. By multiple measures, high-dose oral CS use was associated with a significantly increased risk of adverse events.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/corticosteroid-related-adverse-events-in-patients-with-giant-cell-arteritis-a-claims-based-analysis/