Nonsteroidal Anti-inflammatory Drugs-sparing Effect of Symptomatic Slow-acting Drugs for Osteoarthritis in Knee Osteoarthritis Patients

ABSTRACT

OBJECTIVE: To evaluate the nonsteroidal anti-inflammatory drugs (NSAID)-sparing effect of symptomatic slow-acting drugs for osteoarthritis (SYSADOA) in knee osteoarthritis (OA) patients. METHODS: A retrospective study was conducted on a cohort of knee OA patients who visited a single academic referral hospital from 2013 to 2014. Among all patients, NSAID users in their first visit were extracted and divided into SYSADOA users and SYSADOA non-users. All patients were observed from their first visit with knee OA to their last visit, NSAID discontinuation, or the date of data collection, July 2017 (mean observational periods 369.1 days). To evaluate the NSAID-sparing effect of SYSADOA, Cox regression analysis was performed after adjusting for confounding factors. RESULTS: Patients for this study (n=212) were divided into SYSADOA users (n=57) and SYSADOA non-users (n=155). The mean age (68.8 vs. 66.6 years old, p=0.31) and the number of comorbidities (p=0.73) were comparable between the two groups. The SYSADOA users showed higher Kellgren–Lawrence (KL) grade (66.7% of patients with more than KL grade 3) than SYSADOA non-users (42.6% of patients with more than KL grade 3) (p=0.02). In treatment, the frequency of intra-articular injection was higher in the SYSADOA user group than the SYSADOA non-user group (33.3% vs. 9.0%, p<0.01). In Cox regression analysis, SYSADOA use contributed to NSAID discontinuation in knee OA patients (hazard ratio 2.97, 95% confidential interval 1.42∼6.22). CONCLUSION: This real-world analysis demonstrated that SYSADOA use combined with NSAIDs had a significant effect on NSAID discontinuation in patients with knee OA.