Rief 2012.

Study characteristics
Methods	Type: preclinical Design: parallel and 2 × 3 + 1 factorial design with a separate no treatment group as well as 6 groups separated by the following factors. Active placebo or standard placebo 100% drug expectation, 50% drug expectation, or 100% placebo expectation Objective: to investigate the effects of manipulating the expectation of receiving an active drug, and of medication‐associated bodily sensations, to estimate the influence of these RCT‐typical features. Treatment duration: instant (single dose) Follow‐up duration (including treatment duration): 20 minutes Washout between cross‐over periods: NA
Data	Country: Germany Condition: experimental heat pain Number of people randomised: 144 volunteers included, unclear how many were randomised to each group. 57 randomised to each placebo type. Number of people analysed: 57 for each placebo type
Comparisons	Active placebo: capsaicin (0.014 %) in sesame oil Standard placebo: sesame oil Experimental intervention: none Administration: intranasal
Outcomes	Participant‐reported outcome: pain threshold (in degrees centigrade) Observer‐reported outcome: none Harm outcome: none Co‐intervention outcome: none
Terminology for active placebo	"Active placebo" a priori
Scores and unpleasantness of the active placebo	Adequacy: NA Risk of therapeutic effect: 2 Unpleasant/neutral/pleasant: unpleasant
Funding and conflicts of interest	Non‐industry funding. Trial authors declared no conflicts of interest.
Notes
Risk of bias
Item	Authors' judgement	Support for judgement
Free from risk of bias arising from the randomisation process	Unclear	No indication of problems with baseline differences. No other information.
Free from risk of bias in selection of the reported result All outcomes	Unclear	No information.