Gastrointestinal risk of non-steroidal anti-inflammatory drugs and gastroprotective agents used in the treatment of osteoarthritis in elderly patients: A nationwide retrospective cohort study .

OBJECTIVE: Osteoarthritis is highly prevalent in older adults and often treated with nonsteroidal anti-inflammatory drugs (NSAIDs). COX-2-selective NSAIDs have been shown to offer better gastrointestinal (GI) safety benefits than non-selective NSAIDs (ns-NSAIDs). However, most COX-2-selective NSAIDs have not been comprehensively evaluated for use in combination with gastroprotective agents (GPAs). This study compared the risk of adverse GI events in patients treated with COX-2-selective NSAIDs and ns-NSAIDs alone, or in combination with GPAs.
MATERIALS AND METHODS: We utilized National Health Insurance Claim Data collected from 2012 to 2015. Newly diagnosed patients with osteoarthritis (60 years or older) were included in this study. The study population was divided into two groups: 1) COX-2-selective NSAID treatment and 2) ns-NSAIDs treatment. Patients were followed-up for up to 6 months to determine whether GI events occurred. The Cox proportional hazards model was used to identify differences in risk. Subgroup analyses were conducted for monotherapies and combination treatments with GPAs.
RESULTS: The number of subjects prescribed COX-2-selective NSAID and ns-NSAIDs were 20,868 (5.6%) and 353,494 (94.4%), respectively. After adjustment for confounding factors, COX-2-selective NSAID were safer than ns-NSAIDs (adjusted hazard ratio (aHR) = 0.80, 95% confidence interval (CI): 0.77 - 0.82). Use of GPAs with COX-2-selective NSAID was associated with a lower risk of GI events than use of ns-NSAIDs (aHR = 0.92, 95% CI: 0.87 - 0.97).
CONCLUSION: Use of COX-2-selective NSAID was associated with a lower risk of GI adverse events than use of ns-NSAIDs as a monotherapy. Furthermore, COX-2-selective NSAID were safer than ns-NSAIDs in combination with GPAs.
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