Eleven RCTs (n=624 patients, calculated from tables) were included. Five studies scored 3 or more on the quality assessment, three studies scored 2 and three studies scored 1.
Renal function (eight RCTs, n=461 patients): Treatment with ACEIs/ARBs had a superior benefit over controls in preserving renal function (OR 0.29, 95% CI 0.17 to 0.49 from forest plot). Discrepancies were noted between figures reported in the text (reported as RR) and those from the forest plot.
Daily proteinuria (seven RCTs, n=463 patients): ACEIs/ARBs were associated with a statistically significant reduction in proteinuria compared with controls (WMD -0.67, 95% CI -0.85 to -0.49).
Adverse effects (three RCTs, n=219 patients): There were no significant differences in any adverse effect between the groups.
Patient characteristics: Fixed-effect meta-regression found no significant differences between treatment groups in age or creatinine clearance at baseline. Reductions in systolic and diastolic blood pressures were similar between the treatment groups. There was no evidence of statistical heterogeneity.
Sensitivity analyses: Model choice (random-effects or fixed-effect) or study quality did not influence the results.
Results from funnel plots and Begg's test showed no evidence of publication bias.