A Pilot Trial to Assess the Effectiveness of Screening for CKD among High Risk Patients

Currently, the value of screening for chronic kidney disease (CKD) is uncertain. Previous evidence suggests that in certain high-risk groups, screening may be cost-effective in reducing the burden of complications associated with CKD. More than 20 million adults in the United States are affected by CKD, defined by either of two readily available clinical tests: estimated glomerular filtration rate <60 mL/min/1.73 m2 or albumin-to-creatinine ratio (ACR) ≥30 mg/g.

Individuals with CKD are at risk for cardiovascular events, progression to end-stage renal disease, hospitalization, decline in cognitive and physical function, and death. Early detection and classification of CKD provides guidance for treatment for improving blood pressure, increasing use of renin-angiotensin system inhibitors (ACE or ARB) for patients with proteinuria, and the withdraw of certain nephrotoxic medications. Because CKD is largely asymptomatic, it often is undetected until it has advanced.

Because of limited evidence as to whether screening for CKD in high-risk groups affects clinical outcomes, there is no agreement on a national systematic program to screen for CKD in the United States. Carmen A. Peralta, MD, MAS, and colleagues recently designed and implemented a pilot, cluster-randomized pragmatic trial aimed at examining the feasibility, implementation, and effectiveness of a triple marker CKD screening program. The researchers reported preliminary results from the ongoing study online in BMC Nephrology [2017.doi: 10.1186/s12882-017-0541-6].

The markers of interest were serum creatinine, cystatin C, and urine ACR. The study population included non-diabetic veterans receiving primary care at the San Francisco Veterans Health Care System Medical Practice Clinic over a period of 12 months. The trial included three groups: one usual care arm and two intervention arms. The two interventions arms underwent incrementally intensified treatment strategies: (1) screen for CKD followed by patient and provider education or (2) screen and educate followed by a CKD and blood pressure management program led by a clinical pharmacist.

The researchers identified 2293 patients at the clinic who met initial inclusion criteria. Of those, 114 were excluded because they were assigned to a provider who did not consent or to a study physician. Following review of patient lists, providers excluded another 138 patients. Following application of other exclusion criteria, the final study cohort included 1819 patients.

The median age was 68 years, all but eight were male, 16% were black, and 5% were Hispanic. At study start, 18% had active prescriptions for nonsteroidal anti-inflammatory drugs and 35% were being treated with an ACE/ARB. Approximately 91% had a prior serum creatinine test and 50% had a prior urinary dipstick result in their chart. Fewer than 10% had ACR tested prior to randomization.

Forty-one provider teams representing 70 individual providers were randomized. Following agreement to participate and randomization, two primary care physicians left the practice, potentially affecting 179 patients. Those patients were reassigned to an appropriate provider with availability, who may or may not have been randomized to the same trial arm as the original provider. Also, 14 residents graduated and their patients are expected to be reassigned to new trainees or existing providers; changes in resident panels may affect 345 patients.

During the first 6 months of the study, 434 discrete patients with appointments have been identified in the intervention arms; orders for triple marker screening have been entered. Of those, 217 have been tested as of September 15, 2016. Among those tested, the researchers have identified 48 new cases of CKD (22%), and two cases of acute kidney injury.

To date, there have been no complaints from the providers regarding the study, and a total of 217 research notes have been sent to the primary care physician for signature.  Since protocol implementation, the primary investigator has attended two staff meetings to provide answers to questions about the study.

Also following implementation of protocol, there has been one meeting with the participating pharmacists to ensure fidelity of the pharmacy visit flow. All three participating pharmacists were able to verify the study procedures at the meeting.

“In summary, we describe a successful implementation of a pilot randomized controlled trial to evaluate the effectiveness of CKD screening to improve processes of care among hypertensive veterans without diabetes. Results for this study can guide design of pragmatic trials in the field of CKD,” the researchers said.

Takeaway Points

  1. It is unclear whether screening for chronic kidney disease (CKD) can improve the care of patients at high risk for complications associated with CKD such as hypertension, progression to end-stage renal disease, and cardiovascular events.
  2. Researchers in San Francisco have developed a pilot, cluster-randomized pragmatic trial to assess the feasibility, implementation, and effectiveness of a triple marker approach to CKD screening.
  3. To date (6 months into the 12-month trial period), implementation of the pilot trial has been successful in improving processes of care among the study population (hypertensive veterans without diabetes).