Group-delivered interventions for lowering blood pressure in hypertension: a systematic review and meta-analysis

Background Hypertension is the leading modifiable cause of cardiovascular disease. Primary care management is predominantly individual and remains suboptimal. Interventions delivered to groups incorporate peer support and potentially offer efficient use of limited resources. Evidence for the benefits of group- delivered interventions in hypertension is unclear. Aim To determine whether group- delivered hypertension interventions improve blood pressure (BP) outcomes compared to usual care (UC). Design and setting Systematic review, meta-analyses, and meta-regression of randomised controlled trials in community, primary, or outpatient care settings. Method MEDLINE, Embase, Cochrane CENTRAL, and CINAHL were searched from inception to 20 March 2024 for randomised controlled trials comparing group-delivered interventions to UC for adults with hypertension. Primary outcomes were changes in systolic and diastolic BP, achievement of study BP targets and medication adherence; quality was assessed using the Cochrane Risk of Bias 2 tool. Data were pooled according to intervention type using random effects meta-analyses; predictors of BP lowering were modelled with meta-regression. Results Overall, 5326 citations were retrieved; 59 intervention groups (IGs) from 54 studies (13 976 participants) were included. Compared to UC, systolic BP reduced by 7.2 mmHg (95% confidence interval [CI] = 4.7 to 9.6; 23 IGs) following exercise, 4.8 mmHg (95% CI = 3.2 to 6.4; 26 IGs) following lifestyle education, and 3.6 mmHg (95% CI = 0.3 to 6.9; seven IGs) following psychotherapeutic interventions. Corresponding reductions in diastolic BP were 3.9 mmHg (95% CI = 2.6 to 5.2; 21 IGs), 2.9 mmHg (95% CI = 1.8 to 3.9; 24 IGs), and 1.2 mmHg (95% CI = -1.9 to 4.3; seven IGs). Achievement of target BP and medication adherence were infrequently reported, with equivocal findings (relative risks 1.1, 95% CI = 1.0 to 1.2, P = 0.02, 11 IGs and 1.0,95%CI = 1.0 to 1.1, P = 0.60, seven IGs, respectively). In multivariable models, higher baseline BP and pre- existing cardiovascular morbidity were associated with greater BP reductions. Conclusion Group-delivered interventions were effective at lowering BP for people with hypertension compared with UC; their feasibility and cost- effectiveness in primary care require further study.