Comparison 1: diet and physical activity versus usual care (main outcomes)
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Participants, n (studies) | Certainty of the evidence (GRADE) | |
| Risk with usual care | Risk with diet+physical | ||||
| SBP (mm Hg) | The mean SBP was 130.63 mm Hg. | MD 2.72 mm Hg lower (from 4.11 lower to 1.33 lower) | – | 14 589 (12 RCTs) | ⊕⊕⊕◯ Moderate† |
| SBP (mm Hg), no medications | The mean SBP, no medications, was 127.4 mm Hg. | MD 1.72 mm Hg lower (from 3.71 lower to 0.27 higher) | – | 11 715 (5 RCTs) | ⊕⊕⊕⊕High |
| SBP (mm Hg), medications | The mean SBP, medications, was 133.86 mm Hg. | MD 3.61 mm Hg lower (from 5.63 lower to 1.59 lower) | – | 2874 (7 RCTs) | ⊕⊕⊕ ◯ Moderate‡ |
| DBP (mm Hg) | The mean DBP was 85.39 mm Hg. | MD 1.53 mm Hg lower (from 2.57 lower to 0.48 lower) | – | 14 527 (11 RCTs) | ⊕⊕ ◯◯ Low§¶ |
| DBP (mm Hg), no medications | The mean DBP, no medications, was 84.93 mm Hg. | MD 0.67 mm Hg lower (from 2.36 lower to 1.01 higher) | – | 11 653 (4 RCTs) | ⊕⊕⊕ ◯ Moderate** |
| DBP (mm Hg), medications | The mean DBP, medications, was 85.85 mm Hg. | MD 2.05 mm Hg lower (from 3.35 lower to 0.75 lower) | – | 2874 (7 RCTs) | ⊕⊕⊕ ◯ Moderate¶ |
| Hypertension (yes/no) | 34 per 1000 | 16 per 1000 (6–46) | RR 0.47 (0.17–1.35) | 635 (2 RCTs) | ⊕⊕⊕ ◯ Moderate‡‡ |
| Incidence of diabetes (yes/no) | 15 per 1000 | 18 per 1000 (6–60) | RR 1.25 (0.39–4.06) | 661 (2 RCTs) | ⊕⊕⊕ ◯ Moderate‡‡ |
*The risk in the intervention group (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).
*I2 statistic=54%, p=0.01, implying significant heterogeneity between studies without a lot of overlap in CIs.
†I2 statistic=58%, p=0.03, implying significant heterogeneity between studies without a lot of overlap in CIs.
‡I2 statistic=67%, p=0.0008, implying significant heterogeneity between studies without a lot of overlap in CIs.
§Egger’s test: p=0.013.
¶I2 statistic=61%, p=0.02, implying significant heterogeneity between studies without a lot of overlap in CIs.
**I2 statistic=69%, p=0.02, implying significant heterogeneity between studies without a lot of overlap in CIs.
††Optimal Information Size (OIS) not met.
CI, confidence interval; DBP, diastolic blood pressure; MD, mean difference; RCT, randomised controlled trial; RR, relative risk; SBP, systolic blood pressure.