Carter 1970.

Methods	Randomized, single site study conducted in UK. Participants were stroke survivors admitted to hospital and followed in clinics.
Participants	99 participants of which 71 were aged 18 to 59 years; 54% men; age range: 40‐79; mean: 69 years; race/ethnicity: not reported. Mean BP at entry: not reported. Pre‐existing factors: stroke: 100%; BP entry criteria: SBP > 160 mmHg and DBP < 110 mmHg) or DBP ≥ 110 mmHg irrespective of SBP. Exclusion criteria: cerebral haemorrhage; embolism; tumour; accelerated hypertension; "those with an obvious need for hypotensive therapy;" left ventricular failure; congestive cardiac failure; gross radiological cardiac enlargement; various cardiac arrhythmias or evidence of renal failure. Mean follow‐up: 4.0 years.
Interventions	Treatment: first choice: thiazide diuretic (dose or type of thiazide not specified; assumed to be high‐dose thiazide); second choice: methyldopa; third choice: bethanidine, debrisoquine or guanethidine. Control: observation without placebo.
Outcomes	All‐cause mortality; stroke; CHD; CHF not reported for 18‐ to 59‐year‐old subgroup.
Notes	Definition of total cardiovascular outcomes: not reported. Dropouts due to adverse events: not reported. Quality of life or functional status outcomes: not reported. Percentage of participants not on assigned therapy at study end: not reported. Difference in BP at study end: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Placed at random into treated (50) or control (49) groups. The two groups matched reasonably closely with regard to numbers, age, sex, and severity of hypertension." Comment: method of randomization not described. Probably randomization achieved as groups matched at baseline.
Allocation concealment (selection bias)	Low risk	Method for allocation concealment not mentioned. Probably achieved as groups matched well at baseline.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Did not state blinding of participants or personnel. Treating physicians aware of treatment being prescribed.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention blinding of outcome assessor.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "2 out of 99 patients (2%) have been lost to follow‐up, a treated man aged 65 and untreated women of 70 ‐ so results are available for 49 treated and 48 untreated patients." Comment: attrition rate was low and although reason for loss to follow‐up not mentioned, it could not have affected the outcome analysis.
Selective reporting (reporting bias)	Low risk	Protocol not available to confirm reporting bias. Mortality rate and recurrence rate of strokes mentioned as study objectives were reported in results section. Quote: "Figures for minor strokes or transient cerebral ischaemic attacks are not available."
Other bias	Low risk	"Part of the expenses of this research project was covered by a grant from the clinical research subcommittee of the North West Metropolitan Regional Hospital Board."