Morgan 1997.

Methods	randomised crossover trial. After 4 weeks placebo run‐in period, patients received perindopril in the morning and at bedtime each for 4 weeks sample size calculation: not stated. carryover effects: not reported no washout period between treatment arms
Participants	Country: Australia Number randomised:20, 20 completed Age range: 33‐78 yeas mean age: 68±5 years gender: 20 male Ethnicity: not reported inclusion criteria: seated DBP 95‐110 mm Hg, less than 5 mm Hg difference between the two values, and mean 24 h DBP>85 mm Hg. exclusion criteria: clinic SBP >220 mm Hg, had a history of acute cerebrovascular or coronary events within the preceding 6 months, creatinine > 0.16 mmol/l, and liver function test results 50% greater than the normal range.
Interventions	4 mg od perindopril at 0900h or at 2100h
Outcomes	Mortality: not reported Morbidity: not reported Blood Pressure data:24h BP change by 24h ABPM, data was obtained from graph and text ( fig 2 on 209) Adverse Events: not reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	not reported
Allocation concealment (selection bias)	Unclear risk	not reported
Blinding (performance bias and detection bias) All outcomes	High risk	not used
Incomplete outcome data (attrition bias) All outcomes	Low risk	All patients completed, 2 patients ABPM data was eliminated
Selective reporting (reporting bias)	High risk	Morning SBP, DBP were not reported
Other bias	Unclear risk	carryover effects were not reported