Kidney trajectory charts improve GP management of patients with reduced kidney function: a randomised controlled vignette study

Background: 

The stages of chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR) reference ranges are currently determined without considering age.

Aim: 

To determine whether a chart that graphs age with eGFR helps GPs make better decisions about managing patients with declining eGFR. 

Design & setting: A randomised controlled vignette study among Australian GPs using a percentile chart plotting the trajectory of eGFR by age. 

Method: 

Three hundred and seventy-three GPs received two case studies of patients with declining renal function. They were randomised to receive the cases with the chart or without the chart, and asked a series of questions about how they would manage the cases. 

Results: 

In an older female patient with stable but reduced kidney function, use of the chart was associated with GPs in the study recommending a longer follow-up period, and longer time until repeat pathology testing. In a younger male First Nations patient with normal but decreasing kidney function, use of the chart was associated with GPs in the study recommending a shorter follow-up period, shorter time to repeat pathology testing, increased management of blood pressure and lifestyle, and avoidance of nephrotoxic medications. This represents more appropriate care in both cases. 

Conclusion: 

Having access to a chart of percentile eGFR by age was associated with more appropriate management review periods of patients with reduced kidney function, either by greater compliance with current guidelines or greater awareness of a clinically relevant kidney problem.