Sponsorship-Related Outcome Selection Bias in Published Economic Studies of Triptans

Background . Economic studies funded by the pharmaceutical industry are more likely to report favorable results and recommendations for the sponsor’s product than are studies funded by nonindustry establishments. Purpose . To determine whether clinical outcome data obtained from the same meta-analyses are used differently in various economic studies of oral triptans and whether there is an association between the study sponsorship and the choice of clinical outcome measure. Data Sources . Economic studies of triptans were identified by updating a previously published systematic review. Study Selection . Twelve studies that used the same meta-analyses as the source of clinical outcome data were identified. Data Extraction . Two independent reviewers extracted the essential data from the identified studies. Data Synthesis . In the 12 appraised studies, 9 alternative measures of effectiveness were derived from the same meta-analyses. Eleven studies were industry-related, and in these the selected clinical outcome consistently favored the sponsor’s product. Also the reported results suggested that the sponsor’s product was more cost-effective than the competitors’ products. Limitations . The cost-effectiveness of triptans is dependent on both the definition of clinical effectiveness and the treatment-related costs. Only bias related to the selection of the clinical outcome measure has been taken into account in this review. Conclusions . The results of published economic studies of triptans are conflicting and biased. There is a tendency to select clinical outcome measures that support the sponsor’s product. This leads to concern about the possible poor applicability of these results in decision making.