Background: This is the second substantive update of this review. It was originally published in 1998 and was previously updated in 2009. Elevated blood pressure (known as 'hypertension') increases with age - most rapidly over age 60. Systolic hypertension is more strongly associated with cardiovascular disease than is diastolic hypertension, and it occurs more commonly in older people. It is important to know the benefits and harms of antihypertensive treatment for hypertension in this age group, as well as separately for people 60 to 79 years old and people 80 years or older.

Objectives: Primary objective• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on all-cause mortality in people 60 years and older with mild to moderate systolic or diastolic hypertensionSecondary objectives• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on cardiovascular-specific morbidity and mortality in people 60 years and older with mild to moderate systolic or diastolic hypertension• To quantify the rate of withdrawal due to adverse effects of antihypertensive drug treatment as compared with placebo or no treatment in people 60 years and older with mild to moderate systolic or diastolic hypertension SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to 24 November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

Selection criteria: Randomised controlled trials of at least one year's duration comparing antihypertensive drug therapy versus placebo or no treatment and providing morbidity and mortality data for adult patients (≥ 60 years old) with hypertension defined as blood pressure greater than 140/90 mmHg.

Data collection and analysis: Outcomes assessed were all-cause mortality; cardiovascular morbidity and mortality; cerebrovascular morbidity and mortality; coronary heart disease morbidity and mortality; and withdrawal due to adverse effects. We modified the definition of cardiovascular mortality and morbidity to exclude transient ischaemic attacks when possible.

Main results: This update includes one additional trial (MRC-TMH 1985). Sixteen trials (N = 26,795) in healthy ambulatory adults 60 years or older (mean age 73.4 years) from western industrialised countries with moderate to severe systolic and/or diastolic hypertension (average 182/95 mmHg) met the inclusion criteria. Most of these trials evaluated first-line thiazide diuretic therapy for a mean treatment duration of 3.8 years.Antihypertensive drug treatment reduced all-cause mortality (high-certainty evidence; 11% with control vs 10.0% with treatment; risk ratio (RR) 0.91, 95% confidence interval (CI) 0.85 to 0.97; cardiovascular morbidity and mortality (moderate-certainty evidence; 13.6% with control vs 9.8% with treatment; RR 0.72, 95% CI 0.68 to 0.77; cerebrovascular mortality and morbidity (moderate-certainty evidence; 5.2% with control vs 3.4% with treatment; RR 0.66, 95% CI 0.59 to 0.74; and coronary heart disease mortality and morbidity (moderate-certainty evidence; 4.8% with control vs 3.7% with treatment; RR 0.78, 95% CI 0.69 to 0.88. Withdrawals due to adverse effects were increased with treatment (low-certainty evidence; 5.4% with control vs 15.7% with treatment; RR 2.91, 95% CI 2.56 to 3.30. In the three trials restricted to persons with isolated systolic hypertension, reported benefits were similar.This comprehensive systematic review provides additional evidence that the reduction in mortality observed was due mostly to reduction in the 60- to 79-year-old patient subgroup (high-certainty evidence; RR 0.86, 95% CI 0.79 to 0.95). Although cardiovascular mortality and morbidity was significantly reduced in both subgroups 60 to 79 years old (moderate-certainty evidence; RR 0.71, 95% CI 0.65 to 0.77) and 80 years or older (moderate-certainty evidence; RR 0.75, 95% CI 0.65 to 0.87), the magnitude of absolute risk reduction was probably higher among 60- to 79-year-old patients (3.8% vs 2.9%). The reduction in cardiovascular mortality and morbidity was primarily due to a reduction in cerebrovascular mortality and morbidity.

Authors' conclusions: Treating healthy adults 60 years or older with moderate to severe systolic and/or diastolic hypertension with antihypertensive drug therapy reduced all-cause mortality, cardiovascular mortality and morbidity, cerebrovascular mortality and morbidity, and coronary heart disease mortality and morbidity. Most evidence of benefit pertains to a primary prevention population using a thiazide as first-line treatment.

Vijaya Musini: nothing to declare.

Aaron Tejani: nothing to declare.

Ken Bassett: nothing to declare.

Lorri Puil: nothing to declare.

James Wright: nothing to declare.