Table 2.

Risk of bias in included trials

	Blinding: caregivers	Blinding: patients	Blinding: outcome assessors	Blinding: data collectors	Allocation concealment	Lost to follow-up	Funding source	Trial stopped early
APLASA	Yes	Yes	Yes	Yes	Yes	5%	FP	No
ETDRS	Yes	Yes	Yes	Yes	Yes	>10%	NFP	No
Hypertension Optimal Treatment	Yes	Yes	Yes	No	Yes	3%	FP	No
JPAD	No	No	Yes	Yes	Yes	8%	NFP	No
Physicians' Health Study	Yes	Yes	Yes	NR/NC	NR/NC	<1%	FP	No
POPADAD	Yes	Yes	Yes	Yes	Yes	<1%	FP	No
Primary Prevention Project	No	No	NR	No	Yes	NR/NC	FP	Yes
Women's Health Study	Yes	Yes	Yes	No	NR/NC	NR/NC	FP	No

FP, includes for-profit sources; NFP, does not include for-profit sources; NR/NC, profit status not reported or not clear.