Background and objectives

In the Control of Blood Pressure and Risk Attenuation trial, a 2×2 factorial design study (2004-2007), the combined home health education and trained general practitioner intervention delivered over 2 years was more effective than no intervention (usual care) in lowering systolic BP among adults with hypertension in urban Pakistan. We aimed to assess the effectiveness of the interventions on kidney function.

Design, participants, settings, & methods

In 2012-2013, we conducted extended follow-up of a total of 1271 individuals aged ≥40 years with hypertension (systolic BP ≥140 mmHg, diastolic BP ≥90 mmHg, or receipt of antihypertensive treatment) and serum creatinine measurements with 2 years in-trial and 5 years of post-trial period in 12 randomly selected low-income communities in Karachi, Pakistan. The change in eGFR from baseline to 7 years was assessed among randomized groups using a generalized estimating equation method with multiple imputation of missing values.

Results

At 7 years of follow-up, adjusted mean eGFR remained unchanged, with a change of -0.3 (95% confidence interval [95% CI], -3.5 to 2.9) ml/min per 1.73 m(2) among adults randomly assigned to the combined home health education plus trained general practitioner intervention compared with a significant decline of -3.6 (95% CI, -5.7 to -2.0) ml/min per 1.73 m(2) in those assigned to usual care (P=0.01, modified intention-to-treat analysis). The risk for the combined intervention of death from kidney failure or >20% decline in eGFR relative to usual care was significantly reduced (risk ratio, 0.47; 95% CI, 0.25 to 0.89).

Conclusions

The combined home health education plus trained general practitioner intervention is beneficial in preserving kidney function among adults with hypertension in communities in Karachi. These findings highlight the importance of scaling up simple strategies for renal risk reduction in low- and middle-income countries.