Not in meta‐analysis
Study	Outcome	Notes
Insufficient data
Fangman 1963	Pricking pain threshold in terms of seconds for 12 spots (and 2 other outcomes: pricking pain at spot C, and ischaemic pain)	Uncertainty on how to use in meta‐analysis. Reports individual patient point estimates, individual baseline standard deviations and F‐score from ANOVA tests. For 12 cases (3 outcomes among 4 participants), active placebo was better in 4 cases, worse in 1 case and not significantly different in the remaining cases. We were not able to determine the size and precision of a potential effect.
Shader 1964	Revised Clyde Mood Scales (subjects)	Not enough data for meta‐analysis. However, it is also unclear if the outcome has an obvious direction of benefit.
Solomon 1960	Questionnaire covering 10 categories (household activities, social activities, resting, motor performance, sleeping, pain, psychological distress, well‐being, interest and participation in environment, and libidinal stimulation)	12 patients were analysed. The 4 drugs were ranked from worst to best (1 to 4) in the categories where active placebo received an average ranking of 2.7 and standard placebo 3.1. The trial did not report whether this difference was significant. Looking at the change over time, the active placebo improved in 7/9 categories and the standard placebo in 4/9 categories
No relevant data
Adelson 1962	No indication of a relevant outcome measured
Casey 1960	No indication of a relevant outcome measured
Kurland 1961	No indication of a relevant outcome measured
Letemendia 1959	No indication of a relevant outcome measured