for the main comparison.

Antihypertensive drug therapy compared with placebo for mild hypertension
Patient or population: Adults with mild hypertension and no cardiovascular disease Settings: ambulatory Intervention: Stepped care antihypertensive drug therapy Comparison: Placebo
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Placebo	Antihypertensive drugs
Mortality 4 to 5 years	Low risk population		RR 0.85 (0.63 to 1.15)	8912 (4)	⊕⊝⊝⊝ very low	More RCTs needed as a significant benefit may have been missed.
	15 per 1000	13 per 1000 (9 to 17)
	High risk population
	30 per 1000	26 per 1000 (18 to 34)
Total CV events 5 years	Low risk population		RR 0.97 (0.72 to 1.32)	7080 (3)	⊕⊝⊝⊝ very low	More RCTs needed as wide confidence intervals are consistent with a significant benefit or a significant harm.
	15 per 1000	15 per 1000 (11 to 20)
	High risk population
	30 per 1000	29 per 1000 (22 to 40)
Withdrawals due to adverse effects 5 years	Low risk population		RR 4.80 (4.14 to 5.57)	17,354 (1)	⊕⊕⊕⊝ moderate	Withdrawals due to adverse effects are increased. It was downgraded to moderate as it was not limited to a primary prevention population with mild hypertension.
	15 per 1000	72 per 1000 (62 to 84)
	High risk population
	30 per 1000	144 per 1000 (124 to 168)
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk Ratio
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.

The median control group risk was derived from the event rate in the control group i.e. 20 per 1000 mortality, 24 per 1000 total CV events and 23 per 1000 withdrawals due to adverse effects.