PT - JOURNAL ARTICLE AU - Liana Fraenkel AU - Dick R Wittink AU - John Concato AU - Terri Fried TI - Are preferences for cyclooxygenase-2 inhibitors influenced by the certainty effect? DP - 2004 Mar 01 TA - The Journal of Rheumatology PG - 591--593 VI - 31 IP - 3 4099 - http://www.jrheum.org/content/31/3/591.short 4100 - http://www.jrheum.org/content/31/3/591.full SO - J Rheumatol2004 Mar 01; 31 AB - OBJECTIVE: To test whether the widespread use of cyclooxygenase-2 (COX-2) inhibitors may be mediated in part by the certainty effect, i.e., by a perception that COX-2 inhibitors eliminate the risk of serious gastrointestinal (GI) events in contrast to merely reduce their risk. METHODS: Patients' preferences for conventional nonsteroidal antiinflammatory drugs (NSAID) and COX-2 inhibitors for treatment of arthritis were predicted across a range of absolute risks of GI events using an Adaptive Conjoint Analysis survey. RESULTS: Preferences for COX-2 inhibitors were much stronger when the risk of serious GI events was eliminated in contrast to reduced, even though the absolute risk reduction (ARR) was the same. Few patients (22%) preferred COX-2 inhibitors when the risk associated with NSAID and COX-2 inhibitors was 4% and 2%, respectively (ARR = 2%). In contrast, the majority (90%) preferred COX-2 inhibitors when the risk associated with NSAID and COX-2 inhibitors was 2% and 0%, respectively (ARR = 2%). We obtained similar findings regardless of the ARR. CONCLUSION: The willingness shown by older adults to pay for COX-2 inhibitors may reflect a misperception of the risk of toxicity associated with these medications.