Abstract
BackgroundEven in healthy people, kidney function declines with age. However current clinical guidelines on chronic kidney disease management for general practitioners do not take age into consideration, which can lead to both overdiagnosis and underdiagnosis. Guidelines recommend a patient-centred approach, but would be enhanced by more detailed guidance on how this should be applied to different age groups. One tool that has been recommended are charts that compare normal kidney function across different ages.
Aim
We sought to estimate the usual rate of decline in kidney function with healthy ageing. We also aimed to understand how GPs were managing their older patients in the light of this declining kidney function; how they were using the guidelines; and when and why they might deviate from the guidelines. We sought to understand the terminology GPs were using when describing declining kidney function to their patients. We also aimed to test the concept of charts that compared kidney function with age on GPs’ diagnosis and management of declining kidney function in older and younger patients.
Methods
Several studies using different methods were employed to investigate these aims. (1) To determine what the normal rate of kidney function was with increasing age, we did a systematic review of longitudinal studies of decline in kidney function. (2) To understand GP management of older patients with declining kidney function, we performed a mixed methods study and surveyed and interviewed GPs. (3) We also developed a percentile chart that plotted kidney function against increasing age, and used a randomised clinical vignette study to test the impact of chart with GPs. (4) Finally, we conducted a qualitative interview study about GPs perspectives of using a kidney trajectory chart.
Results
Our systematic reviewed determined that the normal rate of decline in kidney function in healthy people ranges from -0.37 to -1.07 mL/min/1.73m2/year. In our mixed methods study we found that GPs prefer to use terms and explanations around kidney function decline rather than only using the term “chronic kidney disease”. We found that GPs deviate from clinical guidelines when managing their older patients with declining kidney function because they are focussing on whole-person care and patient-centred care. When presented with two clinical vignettes, GPs randomized to the kidney trajectory chart that plotted kidney function with age, were less likely to think an older patient had chronic kidney disease. However, using the same chart in a younger patient led GPs to recognise problematic kidney function and intensify their management. GPs thought the kidney trajectory chart could be a very useful tool in clinical practice for monitoring patients, assisting in determining appropriate management at different ages, and help with a patient-centred approach, and felt the chart was something patients could understand and use to monitor their own kidney function.
Conclusion
Kidney trajectory charts could be a useful adjunct to clinical guidelines to assist GPs in the management of patients with declining kidney function, and reduce both underdiagnosis and overdiagnosis. Further research needs to be undertaken to test kidney trajectory charts in a variety of real clinical settings.
| Date of Award | 2024 |
|---|---|
| Original language | English |
| Supervisor | Paul Glasziou (Supervisor) & Jennifer Doust (Supervisor) |