Six clinical trials (eight data sets) were included in the review. Trails were of a total of 6,851 white or non-black participants and 3,371 black participants. Four studies used randomisation and three used blinding. Sample sizes ranged from 68 to 7,609 participants.
An initial meta-analysis of all six cohorts found no statistically significant difference between groups. After removal of two studies to reduce significant heterogeneity, the pooled difference in systolic blood pressure change between blacks and whites was -2.7mmHg (95% CI -4.0 to -1.3; four cohorts) and for diastolic blood pressure was -0.4mmHg (95% CI -1.0 to 0.3; six cohorts) with blacks having greater response. There was no indication of publication bias for the diastolic analysis, but there was for the systolic analysis.
However, whites were just as likely as blacks to attain a diastolic blood pressure goal of less than 90mmHg or a 10mmHg or greater change (RR 1.00, 95% CI 0.91 to 1.11), with little evidence of publication bias.