Non-steroidal anti-inflammatory drugs (NSAIDs), including cyclo-oxygenase-2 (COX-2) inhibitors, are generally contraindicated in chronic kidney disease (CKD). This investigation sought to identify the frequency of NSAID/COX2 prescription and determine the influence of serum Cr versus estimated GFR on this practice pattern.
An established Veterans Health Administration (VHA) CKD safety cohort (n = 70,154) was examined to determine the frequency of NSAID/COX2 in fiscal year 2005 (FY05) for up to 30 days preceding the index hospitalization and as many as 365 days during that year. Binomial regression was used to determine adjusted prevalence ratios for prescription of NSAID/COX2 with respect to continuous eGFR measurement and serum creatinine (Cr) categories. CKD was defined as eGFR < 60 ml/min/1.73m2.
15.4% of subjects had an NSAID/COX2 prescription during the observation period with the proportion prescribed these agents decreasing with declining renal function, but remained significant at any stage of CKD given the renal harm related to these medications. At specific GFR estimates, serum creatinine (Cr) remained a significant predictor of NSAID/COX prescription. At GFR set at 42 ml/min/1.73, the predicted proportion prescribed NSAID/COX2 was 0.29 (95% CI: 0.24,0.36); 0.23 (95% CI: 0.22,0.26); 0.20 (95%: 0.19,0,22); 0.12 (95% CI: 0.10,0.14) for Cr strata of ≤ 1.3 mg/dl, 1.4 – 1.6 mg/dl, 1.7 –2.1 mg/dl, ≥ 2.2 mg/dl, respectively (all p < 0.05).
A significant proportion of individuals with CKD continue to be prescribed NSAID/COX2 and serum Cr remains an influential guide to NSAID/COX2 prescription, even in GFR ranges where these agents are ill-advised.