BACKGROUND: Trials in functional dyspepsia report placebo response rates of 30% to 40%. AIM: We aimed to identify predictors of the placebo response. METHODS:Patients from primary, secondary and tertiary practices with functional dyspepsia defined by Rome II criteria were enrolled into one of four clinical trials; 220 patients were randomized to receive placebo. Scintigraphic assessment of gastric emptying at baseline was repeated at the end of the treatment in those with delayed emptying. After a 2 week run-in period, patients were followed for 8 weeks on placebo. Response was assessed on a weekly basis and a responder was defined as satisfactory relief of meal-related symptoms on at least 50% of weeks. RESULTS:The mean age was 44 years (range 18-82) and 74% were female; 76 (35%) were placebo responders. The predominant symptom was an unstable measure over the trial. Independent predictors of a lower placebo response were lower body mass index and a more consistent predominant symptom pattern (both P < 0.05). No association was seen with age, gender, centre type, baseline symptom score, baseline or change in gastric emptying, or baseline quality of life. CONCLUSION: In functional dyspepsia, a consistent predominant symptom pattern and lower body mass index may be associated with a lower placebo response rate.
RCT Entities:
BACKGROUND: Trials in functional dyspepsia report placebo response rates of 30% to 40%. AIM: We aimed to identify predictors of the placebo response. METHODS:Patients from primary, secondary and tertiary practices with functional dyspepsia defined by Rome II criteria were enrolled into one of four clinical trials; 220 patients were randomized to receive placebo. Scintigraphic assessment of gastric emptying at baseline was repeated at the end of the treatment in those with delayed emptying. After a 2 week run-in period, patients were followed for 8 weeks on placebo. Response was assessed on a weekly basis and a responder was defined as satisfactory relief of meal-related symptoms on at least 50% of weeks. RESULTS: The mean age was 44 years (range 18-82) and 74% were female; 76 (35%) were placebo responders. The predominant symptom was an unstable measure over the trial. Independent predictors of a lower placebo response were lower body mass index and a more consistent predominant symptom pattern (both P < 0.05). No association was seen with age, gender, centre type, baseline symptom score, baseline or change in gastric emptying, or baseline quality of life. CONCLUSION: In functional dyspepsia, a consistent predominant symptom pattern and lower body mass index may be associated with a lower placebo response rate.
Authors: F Cremonini; D C Ziogas; H Y Chang; E Kokkotou; J M Kelley; L Conboy; T J Kaptchuk; A J Lembo Journal: Aliment Pharmacol Ther Date: 2010-03-26 Impact factor: 8.171
Authors: Paul Enck; Sibylle Klosterhalfen; Katja Weimer; Björn Horing; Stephan Zipfel Journal: Philos Trans R Soc Lond B Biol Sci Date: 2011-06-27 Impact factor: 6.237