Os 1999.

Methods	2‐week single‐blind placebo run‐in period; inclusion criteria=DBP 95‐105 mm Hg and SBP ≤180 mm Hg; 12‐week double‐blind treatment, consisting of dose titration period (to achieve target BP ≤90 mm Hg and a 10 mm Hg decrease from baseline 24 h postdose) at 5 weeks
Participants	All patients: n=392; all white; mean age=55.9 (range 24‐80) years Doxazosin GITS: n=161 (75 males, 86 females); mean age=56.4 (range 29‐79) years; baseline sitting SBP=157(14) mm Hg, DBP=99(3) mm Hg, HR=72(8) bpm; baseline standing SBP=158(14) mm Hg, DBP=102(5) mm Hg, HR=76(9) bpm Doxazosin Standard: n=155(72 males, 83 females); mean age=55.6 (range 26‐80) years; baseline sitting SBP=157(14) mm Hg, DBP=99(3) mm Hg, HR=73(9) bpm; baseline standing SBP=158(15) mm Hg, DBP=102(5) mm Hg, HR=77(10) bpm Placebo: n=74(40 males, 34 females); mean age=55.4 (range 24‐78) years; baseline sitting SBP=157(14) mm Hg, DBP=99(3) mm Hg, HR=72(9) bpm; baseline standing SBP=158(14) mm Hg, DBP=101(5) mm Hg, HR=76(10) bpm
Interventions	Doxazosin GITS 4‐8 mg once daily; patients received doxazosin GITS 4 mg for at least 5 weeks; at week 5, dose was increased to 8 mg once daily if target BP not achieved Doxazosin Standard 1‐8 mg once daily; patients received initial dose of 1 mg; dose was increased at 1 week to 2 mg, at 3 weeks to 4 mg, and at 5 weeks to 8 mg if target BP not achieved Placebo Taken at breakfast
Outcomes	Change from baseline in trough sitting SBP/DBP using sphymomanometer Change from baseline in trough standing SBP/DBP using sphymomanometer Change from baseline in trough sitting HR Change from baseline in trough standing HR WDAE
Notes	Used only week 5 BP data for doxazosin GITS; SBP at week 5 not reported; DBP at week 5 reported; DBP SD of change at week 5 not reported; BP change and SD of change reported at endpoint; baseline BP and SD reported; imputed endpoint DBP SD of change; week 5 DBP data from Figure 5, p. 189
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "Two patients randomized to placebo were not eligible for inclusion in the ITT population (n=390) because they had no on‐treatment efficacy assessment."
Selective reporting (reporting bias)	High risk	SBP and safety/tolerability data at week 5 not reported. Quote: "No significant changes in sitting or standing HR were observed in any of the treatment groups." Comment: Quantitative HR data not reported.
Other bias	High risk	Quote: "...those with a known sensitivity to α‐blocking drugs...were also ineligible." Comment: Patient selection bias. Funding source is manufacturer of doxazosin GITS (Pfizer).