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The African American Study of Kidney Disease and Hypertension (AASK) was conducted over a 7-year period at 21 clinical centers across the United States to investigate whether one of two levels of blood pressure control and/or one of three classes of antihypertensive medications was more effective at slowing the rate of renal disease in African Americans with renal insufficiency presumed secondary to hypertension. Analysis at the end of the study revealed an overall participant retention rate of 90% (still alive and not on dialysis); defined as having had at least one 125I-iothalamate GFR, the primary data collection element, measured in the final year of the study.  Adherence, defined as not missing 3 consecutive protocol visits (6 months) during the study, was 77%. Adherence to protocol visits showed that participants assigned to a low blood pressure goal (mean arterial pressure [MAP] of 92 mm/Hg or lower) had a 30% (95% CI, 9% - 45%) lower risk of nonadherence as compared to those assigned to the usual goal [MAP of 102-107] (p = 0.006). No statistically significant difference was observed between randomized drug assignments. Higher baseline systolic (p = 0.0001) and diastolic (p = 0.007) blood pressures were associated with a higher risk of nonadherence. Declining to provide an annual income is associated with a higher risk of nonadherence compared to those with incomes of $15,000 or higher (p = 0.04). In discussing the identifying factors that may predict nonadherence and the strategies that assisted in improving adherence and retention, this article offers insights for researchers in achieving high levels of participation in long-term clinical studies.

Deborah Brooks, MSN, APRN, BC, CNN, CNN-NP, is a Research Coordinator for AASK and Nurse Practitioner in Nephrology, Medical University of South Carolina, Charleston, SC. She is a member of the Nephrology Nursing Journal Editorial Board and of ANNA’s Palmetto Chapter.

Jeanne Charleston, MSN, BSN, RN, is Director of Research Clinical Operations, Johns Hopkins University ProHealth (an offsite community-based research facility), Baltimore, MD.

Donna Dowie, MD, is a Research Associate, Department of Nephrology, Harlem Hospital Columbia University, New York, NY.

Jeanne Charleston, MSN, BSN, RN, is Director of Research Clinical Operations, Johns Hopkins University ProHealth (an offsite community-based research facility), Baltimore, MD.

Avril Gabriel, MPA, RN, NP, was the AASK Study Coordinator, Mount Sinai Medical Center, New York, NY. (deceased)

Yvette Baxter Hall, BSN, RN, MAOM, is a Field Manager, Southeast Territory, Innovex, Parsippany, NJ.

Leena Hiremath, PhD, MS, is a Co-investigator for the AASK at Center 12, a Research Scientist, Division of Nephrology, and Director of the OSU Nephrology Clinical Trials Unit, The Ohio State University Medical Center, Columbus, OH.

Tammy Lightfoot, BSN, RN, is Senior Coordinator for the AASK study and Clinical Manager in Nephrology Research, University of Texas Southwestern Medical Center at Dallas, Dallas, TX. She is a member of ANNA’s Dallas Chapter.

Mohammed Sika, PhD, CCRC, is a Research Associate Professor, Nephrology Clinical Trials Center, Vanderbilt University Medical Center, Nashville, TN.

Winifred C. Smith, BS, MPH, is a Research Subject Advocate, Clinical Research Center, Morehouse School of Medicine, Atlanta, GA.

Xuelei Wang, MS, is a Senior Biostatistician at Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, OH.