Portal de Periódicos da CAPES

Probiotics in irritable bowel syndrome: underachievers or underpowered? authors’ reply

2010; Wiley; Volume: 31; Issue: 8 Linguagem: Inglês

10.1111/j.1365-2036.2010.04239.x

1365-2036

Magnus Simrén, Lena Öhman, Julie Olsson, Ulla Svensson, K. Ohlson, Iris Posserud, Hans Strid,

Infant Health and Development

Sirs, We wish to thank Dr Ford for his interest1 in our recent article published in APT.2 In essence, we agree with the comments made by Dr Ford, and a very likely explanation for the lack of statistical significance between the active treatment group and the control group is that the study was under-powered. However, we have to stress that our assumption of the placebo response rate (15%), using our responder definition, is closer to the observed placebo response in our study (27%), than the pooled placebo response rate from the recent systematic review (43%),3 mentioned by Dr Ford in his letter. Therefore, the incorrect assumption of the placebo response rate does not seem to be a major explanation behind the lack of a statistical difference between the groups. To conclude, we agree that larger studies are needed to assess the effect of probiotics in IBS, to obtain a response to the question posed in the letter by Dr Ford: ‘Probiotics in IBS: underachievers or underpowered?’ We tend to believe that underpowered studies contribute to some of the negative results in the literature, but differences between probiotic products are also of potential importance. Declaration of personal interests: Magnus Simrén has served as a speaker or advisor for AstraZeneca, Novartis, Albireo, Danone, Movetis Addex and Succampo, and has received research funding from AstraZeneca and Danone. Johan Olsson is an employee of KPL Good Food Practice. Ulla Svensson and Kajsa Ohlson are employees of Arla Foods Innovation. Declaration of funding interests: The original study was supported by an unrestricted grant from Arla Foods Innovation, Stockholm, Sweden to the department of Internal Medicine, Sahlgrenska University Hospital, Sweden. This study was supported by the Swedish Medical Research Council (grant 13409), and by the Faculty of Medicine, University of Göteborg.