meta-analyses studying the effi cacy of 5amino salicylates in the prevention of relapse of post-operative Crohn ’ s disease ( 1,2 ). Th e fi rst two papers that they mention ( 3,4 ), which also included patients with medically induced remission, both reported outcome data for patients with a surgically induced remission separately, so we felt it was worthwhile including these extractable data. In neither case did Drs Doherty and Moss ’ s meta-analysis reference these two papers in their extensive list of excluded studies ( 2 ), and given the fact that (in our opinion) they provided extractable data we assumed that they had not been identifi ed successfully. Th e remaining two papers were omitted ( 5,6 ). Whether this is acceptable in a Cochrane review, in the case of the foreign language paper they were unable to obtain ( 5 ), without mentioning this issue specifi cally is debatable when the aim is to assess the totality of published evidence. In the case of the other paper ( 6 ), this was either not identifi ed by their search strategy, or not recognized as being eligible among the citations the search yielded. Fortunately, unlike other instances we have identifi ed where meta-analyses have omitted eligible studies and this has led to erroneous inferences about effi cacy ( 7 ), these diff erences did not lead the two studies to reach disparate conclusions ( 1,2 ). How ever, as we have noted before, systematic reviews and meta-analyses, just like any other scientifi c experiment, may need to be replicated and verifi ed by others in order for readers to have full confi dence in their results. Given that two independent research groups have both suggested that 5-aminosalicylates have an eff ect in reducing the risk of recurrence in post-operative Crohn ’ s disease, this lends strength to the argument that these agents have a role in this setting.
Download Full PDF Version (Non-Commercial Use)