Table 1.
Results of subgroup analysis of renal composite outcome events
| Subgroup | Number of trials | n | RR (95% CI) | P value for RR | I2 | P value for heterogeneity test* |
| Study type | ||||||
| RCT | 1 | 418 | 0.64 (0.43 to 0.98) | 0.04 | – | 0.76 |
| Cohort study | 9 | 9160 | 0.72 (0.57 to 0.90) | 0.005 | 88.6% | |
| Baseline eGFR (mL/min/1.73 m2) | ||||||
| 60–89 | 1 | 171 | 0.14 (0.02 to 1.14) | 0.07 | – | 0.48 |
| 30–59 | 7 | 8869 | 0.71 (0.55 to 0.92) | 0.009 | 90.8% | |
| 15–29 | 2 | 538 | 0.77 (0.63 to 0.94) | 0.01 | 0.0% | |
| Mean age (years) | ||||||
| <58 | 5 | 5691 | 0.58 (0.49 to 0.70) | <0.001 | 56.4% | 0.03 |
| ≥58 | 5 | 3887 | 0.85 (0.69 to 1.05) | 0.14 | 70.1% | |
| Baseline BP (mm Hg) | ||||||
| <140/90 | 6 | 5806 | 0.62 (0.52 to 0.73) | <0.001 | 58.5% | 0.32 |
| SBP ≥140 or DBP ≥90 | 2 | 1646 | 0.70 (0.44 to 1.11) | 0.13 | 74.6% | |
| Comparator of control group | ||||||
| Usual care or usual diet | 2 | 589 | 0.43 (0.11 to 1.64) | 0.21 | 50.2% | 0.12 |
| Different levels of sodium intake | 8 | 8989 | 0.73 (0.58 to 0.92) | 0.008 | 89.8% | |
- The bold P value indicates that there are statistical differences between subgroups.
*P value calculated by meta-regression.
BP, blood pressure; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; n, number of patients; RCT, randomised controlled trial; RR, relative risk; SBP, systolic blood pressure.