Petrie 1976.

Methods	Randomized, double‐blind, placebo‐controlled, cross‐over study. After 14‐day washout period, participants were randomized to a sequence of 4 week treatments
Participants	24 participants (13 males) Inclusion criteria: DBP > 105 mmHg but < 125 mmHg Exclusion criteria: recent MI, evidence of heart failure, heart block, gross ischemia, grade III or IV retinopathy, diabetes, gout, impaired liver function, or creatinine clearance < 60mL/minute or if they were on any other drug treatment
Interventions	Methyldopa 250 mg 3 times daily, practolol 200 mg 3 times daily, propranolol 80 mg 3 times daily, methyldopa 250 mg plus propranolol 80 mg both 3 times daily, methyldopa 250 mg plus practolol 200 mg both 3 times daily, placebo
Outcomes	SBP, DBP, HR, QoL
Notes	SD were imputed using the mean of other studies that provided SD
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information
Allocation concealment (selection bias)	Low risk	Package were pre‐packed
Blinding (performance bias and detection bias) All outcomes	High risk	Participants took the same number of pills
Incomplete outcome data (attrition bias) Primary and secondary outcomes	Low risk	No drop‐outs
Selective reporting (reporting bias)	High risk	SD were not reported