Table 5.
Comparison 2: diet-only intervention 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 | ||||
| Triglycerides (mmol/L) | The mean triglycerides was 1.59 mmol/L. | MD 0.12 mmol/L lower (0.10 lower to 0.06 lower) |
– | 1337 (7 RCTs) |
⊕⊕⊕◯ Moderate† |
| Triglycerides (mmol/L), no medications | The mean triglycerides, no medications, was 1.57 mmol/L. | MD 0.16 mmol/L lower (0.24 lower to 0.08 lower) |
– | 1003 (5 RCTs) |
⊕⊕⊕⊕High |
| Triglycerides (mmol/L) - medications | The mean triglycerides, medications, was 1.24 mmol/L. | MD 0.01 mmol/L lower (0.13 lower to 0.06 lower) |
– | 334 (2 RCTs) |
⊕⊕⊕◯ Moderate‡ |
| HDLc (mmol/L) | The mean HDLc was 1.06 mmol/L. | MD 0.03 mmol/L higher (0.02 lower to 0.07 higher) |
– | 1620 (10 RCTs) |
⊕⊕◯◯ Low§¶ |
| HDLc (mmol/L), no medications | The mean HDLc, no medications, was 1.06 mmol/L. | MD 0.02 mmol/L higher (0.03 lower to 0.08 higher) |
– | 1286 (8 RCTs) |
⊕⊕⊕◯ Moderate** |
| HDLc (mmol/L), medications | The mean HDLc, medications, was 0.54 mmol/L. | MD 0.04 mmol/L higher (0.01 lower to 0.07 higher) |
– | 334 (2 RCTs) |
⊕⊕⊕◯ Moderate‡ |
| LDLc (mmol/L) | The mean LDLc was 2.92 mmol/L. | MD 0.19 mmol/L lower (0.32 lower to 0.06 lower) |
– | 1701 (11 RCTs) |
⊕⊕◯◯ Low††‡‡ |
| LDLc, (mmol/L) no medications | The mean LDLc, no medications, was 3.13 mmol/L. | MD 0.23 mmol/L lower (0.37 lower to 0.08 lower) |
– | 1352 (9 RCTs) |
⊕⊕⊕◯ Moderate†† |
| LDLc (mmol/L), medications | The mean LDLc, medications, was 2.70 mmol/L. | MD 0.2 mmol/L lower (0.3 lower to 0.34 higher) |
– | 334 (2 RCTs) |
⊕⊕⊕◯ Moderate‡ |
| SBP (mm Hg) | The mean SBP was 129.54 mm Hg. | MD 1.25 mm Hg lower (2.66 lower to 0.16 higher) |
– | 1495 (8 RCTs) |
⊕⊕⊕⊕High |
| SBP (mm Hg), no medications | The mean SBP, no medications, was 132.16 mm Hg. | MD 1.19 mm Hg lower (2.78 lower to 0.39 higher) |
– | 1146 (6 RCTs) |
⊕⊕⊕⊕High |
| SBP (mm Hg), medications | The mean SBP, medications was 126.92 mm Hg. | MD 1.47 mm Hg lower (4.57 lower to 1.64 higher) |
– | 349 (2 RCTs) |
⊕⊕⊕◯ Moderate‡ |
| DBP (mm Hg) | The mean DBP was 81.67 mm Hg. | MD 2.05 mm Hg lower (from 2.93 lower to 1.16 lower) |
– | 1495 (8 RCTs) |
⊕⊕⊕⊕High |
| DBP (mm Hg), no medications | The mean DBP, no medications, was 82.34 mm Hg. | 2.22 mm Hg lower (from 3.26 lower to 1.19 lower) |
– | 1146 (6 RCTs) |
⊕⊕⊕⊕High |
| DBP (mm Hg), medications | The mean DBP, medications, was 81 mm Hg. | MD 1.59 mm Hg lower (from 3.27 lower to 0.1 higher) |
– | 349 (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 for subgroup differences is 76.2%, (P=0.04), implying there is significant heterogeneity between the two subgroups of medication use
‡OIS is not met when high-risk studies are removed.
§I2 statistic =84%, p=<0.00001, implying significant heterogeneity between studies without a lot of overlap in CIs.
¶Egger’s test: p=0.003.
**I2 statistic =84%, p=<0.00001, implying significant heterogeneity between studies without a lot of overlap in CIs.
††I2 statistic =80%, p=<0.00001, implying significant heterogeneity between studies without a lot of overlap in CIs.
‡‡Egger’s test: p=0.03.
§§
CI, confidence interval; DBP, diastolic blood pressure; HDLc, high-density lipoprotein; LDLc, low-density lipoprotein; MD, mean difference; RCT, randomised controlled trial; SBP, systolic blood pressure.