Hermida 2009.

Methods	prospective randomized open‐label, blinded endpoint, parallel‐group trial. 3 months of intervention Baseline similarity: age, height, eight, BMI, waist perimeters, BP,HR, laboratory chemistry variables sample size calculation: reported
Participants	Country: Spain Number randomised: 144, 133 completed Mean age: 45.5±11.9(SD) years(awakening),47.6±12.7(SD) years (bedtime) gender: 43 men, 90 women. Ethnicity: not reported Inclusion Criteria: untreated, age≥18 years, conventional SBP between 140 and 179 mm Hg or DBP between 90 and 109 mm Hg, and ABPM awake BP of mean ≥135/85 mm Hg, or asleep mean ≥120/70 mm Hg. Exclusion criteria: pregnant women, shift workers, heavy drinkers, smokers, heavy exercisers, severe arterial or secondary arterial hypertension, type 1 diabetes, and cardiovascular disorders
Interventions	olmesartan (20 mg od) on awakening: N=73 olmesartan (20 mg od) at bedtime:N=71
Outcomes	Mortality: not reported Morbidity: not reported Blood Pressure data: 24h BP change by 48h ABPM, data was obtained from graph and text (fig 4 on page 72) Adverse Events: withdrawals due to adverse events
Notes	supported in part by grants from Ministerio de Educación y Ciencia, Xunta de Galicia, and University of Vigo.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	computerized random‐number generator
Allocation concealment (selection bias)	High risk	one member of the research team use of a list of random numbers
Blinding (performance bias and detection bias) All outcomes	Low risk	investigator obtaining the BP measurements, outcome assessors blinded. Benefits of the PROBE design and its validity compared with double‐blind, placebo‐controlled trials in assessing antihypertensive efficacy based on blinded ABPM measurements have been documented previously (Smith 2003)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data on all participants were reported. 7 lost to follow‐up for no second ABPM available, 3 in daytime group, 4 in bedtime group; 4 withdrawn due to adverse effects, 3 in daytime group, 1 in bedtime group
Selective reporting (reporting bias)	High risk	Morning SBP, DBP were not reported.
Other bias	Low risk	"The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper".