Yates 1988.

Methods	Design: three group parallel trial Purpose: examine the effect of chiropractic treatment on blood pressure
Participants	Patients: out‐patients with hypertension and thoracic subluxation Baseline comparability: NS
Interventions	Placebo: session with a 'chiropractic adjusting device' without it performing the essential manipulative procedure Untreated: no session Experimental: session with a 'chiropractic adjusting device' performing the essential manipulative procedure (Co‐intervention: 5 patients in the placebo and untreated group received hypertensive medication, dose NS)
Outcomes	Diastolic blood pressure reduction (mm Hg) Anxiety
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Blinding? Treatment provider	High risk	Not described as double‐blind (placebo/chiropractic procedure)
Incomplete outcome data addressed? All outcomes	High risk
Free of selective reporting?	Unclear risk	No protocol available
Free of other bias?	Low risk
No signs of variance inequality or skewness?	Unclear risk	Not relevant (not naturally positive continuous outcomes e.g. change)
Trial size > 49?	High risk	N = 14
Clearly concealed allocation + trial size > 49 + drop‐out max 15%	High risk	Trial size < 49

Outcomes: The first outcome listed is the one extracted for the review (all major outcomes for each trial are listed). 
 NS: not stated. 
 VAS: visual analogue scale. 
 EMG: electromyography. 
 GP: general practitioner. 
 Hb: haemoglobin