TABLE 3

Systematic reviews and meta-analyses of the placebo response (pooled PR, percent) in RCTs in various diseases in internal medicine

Note that this list is incomplete, as it reports only the meta-analysis with the largest number of studies included for the given disease.

Study	N^*	Disease	PR Is Higher with… ^**
Ilnyckyj et al., 1997	38	Ulcerative colitis	higher number of visits
Su et al., 2004	21	Crohn’s Disease	longer study duration
Ford et al., 2010	73	IBS	European studies
Talley et al., 2006	4^*	FD	inconsistent symptoms
de Craen et al., 1999a	79	Duodenal ulcers#	higher application frequency
Cremonini et al., 2010	24	Reflux disease	nonerosive reflux disease
Thijs et al., 1990	1^*	Hypertension	older age
Cho et al., 2005	29	CFS	high intervention intensity
Freeman et al., 1999	2^*	PMS	younger age
Lamel et al., 2012	31	Psoriasis	higher drug probability
Narkus et al., 2013	6	Allergy	subcutaneous administration
Wang et al., 2012	34	Asthma	lower baseline severity

CFS, chronic fatigue syndrome; FD, functional dyspepsia; PMS, premenstrual syndrome; PR, placebo response.
↵* Indicates availability of individual patient data; number of RCTs included into analysis.
↵** Only the most influential variable listed.