Background Corticosteroids are often used for treating rheumatoid arthritis. However, minimizing adverse events while maximizing efficacy remains challenging. An alternate-day corticosteroid dose is known to decrease adverse events.
Objectives To investigate the safety and efficacy of an alternate-day corticosteroid dose for treating rheumatoid arthritis.
Methods We have conducted a retrospective cohort study among patients over 18-year-old who started oral corticosteroids (prednisolone and methylprednisolone) as treatment of rheumatoid arthritis from 2005 to 2014 at St. Luke's International Hospital, a tertiary-level community teaching hospital in Tokyo, Japan. Patients were included if they met the American College of Rheumatology/European League Against Rheumatism 2010 classification criteria for rheumatoid arthritis, and had positive anti-cyclic citrullinated peptide antibody. They were excluded for a history of corticosteroid use for other diseases, or if they were lost to follow-up within 1 year after starting corticosteroids. We divided patients into a daily corticosteroid group (QD) and an alternate-day corticosteroid group (QOD). Patients who received both daily and alternate-day corticosteroids were assigned to the daily group. We investigated the percentage of patients without any infection within 1 year after starting corticosteroids. We have conducted multivariate logistic regression model analysis to calculate adjusted odds ratio for QD/QOD to the outcome. We also investigated the mean decrease in C-reactive protein (CRP) at 1 month as a marker of short-term effectiveness, and the percentage of patients free from corticosteroid at one year, using student's t-test.
Results In total, 139 patients were analysed (69 in the QD group, 70 in the QOD group). The maximum dose of corticosteroid in one year was not significantly different in two groups (11.4±7.7 mg/day VS 10.1±5.3 mg/day; P=0.267), and the mean daily dose of corticosteroid in one year was significantly higher in the QD group (6.1±4.4 mg/day vs 3.9±1.7 mg/day; P<0.01).The percentage of patients without any infection was 49.2% in QD group, and 75.7% in QOD group. Univariate analysis showed QD group is significantly associated with higher incidence of infection (P=0.001). After multivariate analysis adjusted with age, gender, initial CRP value, mean daily dose of corticosteroid in one year, use of biologic DMARDs, and duration of rheumatoid arthritis, the odds ratio of QD for any infection in 1 year was 3.9 (95% confidence interval [CI], 1.7–8.8; P=0.001).The mean decrease of CRP at 1 month was 1.5 mg/dl in QD group, and 1.1 mg/dl in QOD group (P=0.435).The percentage of patients free from corticosteroids at one year was 26.1% in QD group, and 58.6% in QOD group (P<0.01). Kaplan-Meier plot showed that QD group patients are more difficult to become free from corticosteroid (log-rank test: p<0.01).
Conclusions Alternate-day corticosteroid dose has a lower adverse event rate and is as effective as a daily corticosteroid dose for treating rheumatoid arthritis.
Disclosure of Interest None declared