Mattarei 1985.

Methods	Design: two period, two group, cross‐over trial Purpose: examine the effect of placebo on arterial hypertension
Participants	Patients: out‐patients with untreated mild essential hypertension Baseline comparability: NS
Interventions	Placebo: capsule Untreated: no capsule (Co‐intervention: no)
Outcomes	Diastolic blood pressure in mm Hg after 4 weeks Systolic blood pressure in mm Hg
Notes	The outcome data was not available.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	NS
Allocation concealment?	Unclear risk	NS
Blinding? Treatment provider	Unclear risk	NS
Blinding? Outcome assessor	Unclear risk	NS
Incomplete outcome data addressed? All outcomes	High risk	Drop‐out > 15% or NS
Free of selective reporting?	High risk	The outcome data was not available.
Free of other bias?	Low risk
Trial size > 49?	High risk	N = 24
Clearly concealed allocation + trial size > 49 + drop‐out max 15%	High risk	Trial size < 49