Meta-analysis: the effects of placebo treatment on gastro-oesophageal reflux disease.
BACKGROUND
There appears to be a significant placebo response rate in clinical trials for gastro-oesophageal reflux disease. Little is known about the determinants and the circumstances associated with placebo response in the treatment of gastro-oesophageal reflux disease (GERD).


OBJECTIVE
To estimate the magnitude of the placebo response rate in randomized controlled trials for GERD and to identify factors that influence this response.


METHODS
A meta-analysis of randomized, double-blind, placebo-controlled trials, published in English language, which included >20 patients with GERD, treated with either a proton pump inhibitor or H(2)-receptor antagonist for at least 2 weeks. Medline, Cochrane and EMBASE databases were searched, considering only studies that reported a global response for 'heartburn'.


RESULTS
A total of 24 studies included 9989 patients with GERD. The pooled odds ratio (OR) for response to active treatment vs. placebo was 3.71 (95% CI: 2.78-4.96). The pooled estimate of the overall placebo response was 18.85% (range 2.94%-47.06%). Patients with erosive oesophagitis had a non-significantly lower placebo response rate than patients without it (11.87% and 18.31%, respectively; P = 0.246). Placebo response was significantly lower in studies of PPI therapy vs. studies of H(2) RAs (14.51% vs. 24.69%, respectively; P = 0.05).


CONCLUSIONS
The placebo response rate in randomized controlled trials for GERD is substantial. A lower placebo response was associated with the testing of PPIs, but not the presence of erosive oesophagitis.
Cremonini
F
F
Beth Israel Deaconess Medical Center, Boston, MA, USA.
Ziogas
D C
DC
Chang
H Y
HY
Kokkotou
E
E
Kelley
J M
JM
Conboy
L
L
Kaptchuk
T J
TJ
Lembo
A J
AJ
D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D015990:Placebo Effect; D010919:Placebos / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D013223:Statistics as Topic; D016896:Treatment Outcome
D005765:Gastrointestinal Agents; D010919:Placebos