Paran 1993.

Methods	Single‐centre study Randomization: two parallel treatment groups and a placebo group; "...patients were double blindly randomized into three treatment groups...." Blinding: "The study was double‐blind...."; no other details provided Withdrawals: 14 patients from placebo arm withdrew due to treatment failure. Lost to follow‐up: 0% Treatment duration: follow‐up for one year. Analysis type: per protocol.
Participants	Geographic region: Israel. Study setting: outpatient clinic N=48 Age range: 40‐65 Gender: all males Race: not reported Blood pressure at entry: Sitting blood pressure ‐ Methyldopa arm (155/102); Placebo arm (154/101) Co‐morbid conditions: not reported Inclusion criteria: Average sitting diastolic blood pressure of 95‐119 mm Hg on two consecutive visits while on placebo for first two to four weeks Exclusion criteria: secondary hypertension; "hypertensive complications"
Interventions	All anti‐hypertensives discontinued and placebo given for two to four weeks. Methyldopa 250‐500 mg twice daily (N=11). Placebo 1‐2 tablets twice daily (N=21). Isradipine 2.5‐5 mg twice daily (N=16). "Titration period lasted eight weeks or until DBP of 90 mm Hg or less was achieved."
Outcomes	Sitting blood pressure (monthly evaluations in the clinic for one year). Pre and post‐exercise (treadmill) blood pressure, heart rate, EKG (two evaluations: one during placebo run‐in period and one at end of year). Heart rate
Notes	Only seven patients originally randomized to the placebo arm were included in the reporting of outcomes secondary to treatment failure. All patients in the methyldopa arm and in the isradipine arm were included in the reporting of outcomes. Assessment of medication compliance: not reported Final number of patients included in each arm when reporting results: methyldopa arm (11), placebo arm (7), isradipine arm (16)
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	"...patients were double blindly randomized into three treatment groups...."
Allocation concealment?	Unclear risk	Not reported.
Blinding? All outcomes	Low risk	Double blind
Incomplete outcome data addressed? All outcomes	High risk	"The placebo included 21 patients at the start; however, only seven of these completed the whole course of one year, the rest having deviated from protocol due to treatment failure....Subjects who did not stay on the same treatment for a year could not be included in the comparative analysis." Study did not provide results data for the 14 patients who received placebo and did not complete the trial
Free of selective reporting?	Low risk	Reported on all pre‐specified outcomes of interest