Colon to Rectum
Am J Gastroenterol. 2022;117(11):1851–7
The association between non-steroidal anti-inflammatory drug use and inflammatory bowel disease exacerbations: A true association or residual bias?
Introduction: Studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs) may contribute to inflammatory bowel disease (IBD) exacerbations. The authors examined whether variation in the likelihood of IBD exacerbations is attributable to NSAIDs.
Methods: In a cohort of patients with IBD (2004–2015), they used 3 analytic methods to examine the likelihood of an exacerbation after an NSAID exposure. First, they matched patients by propensity for NSAID use and examined the association between NSAID exposure and IBD exacerbation using an adjusted Cox proportional hazards model. To assess for residual confounding, they estimated a previous event rate ratio and used a self-controlled case series analysis to further explore the relationship between NSAIDs and IBD exacerbations.
Results: The authors identified 15,705 (44.8%) and 19,326 (55.2%) IBD patients with and without an NSAID exposure, respectively. Findings from the Cox proportional hazards model suggested an association between NSAIDs and IBD exacerbation (hazard ratio [HR] = 1.24; 95% confidence interval [CI]: 1.16–1.33). However, the likelihood of an IBD exacerbation in the NSAID-exposed arm preceding NSAID exposure was similar (HR = 1.30; 95% CI: 1.21–1.39). A self-controlled case series analysis of 3968 patients who had both an NSAID exposure and IBD exacerbation demonstrated similar exacerbation rates in the 1 year preceding exposure, 2–6 weeks postexposure, and 6 weeks to 6 months postexposure, but a higher incidence in 0–2 weeks postexposure, suggesting potential confounding by reverse causality.
Discussion: While an association between non-steroidal anti-inflammatory drugs (NSAIDs) and inflammatory bowel disease exacerbations using traditional methods was seen, further analysis suggests this may be secondary to residual bias. These findings may reassure patients and clinicians considering NSAIDs as a non-opioid pain management option.