eGFR vs. ACR: Why Both Tests Matter

Diabetes Canada recommends screening people living with diabetes for chronic kidney disease using both an estimated glomerular filtration rate (eGFR) and a urine albumin-to-creatinine ratio (ACR). In people with type 2 diabetes, this screening begins at diagnosis. For people with diabetes whose results are normal, the Alberta Chronic Kidney Disease Clinical Pathway recommends repeating both tests annually (Alberta Health Services, n.d.).

Despite recommendations, recommended kidney screening is still not consistently being completed. In a Canadian retrospective cohort study using the Canadian Primary Care Sentinel Surveillance Network, only 13% of adults living with diabetes received both annual eGFR and urine ACR screening as recommended. While 94.1% of patients had eGFR testing performed during the study period, only 76.6% underwent urine ACR testing, demonstrating that urine screening continues to lag behind bloodwork despite longstanding guideline recommendations (Black et al., 2024).

This gap matters because chronic kidney disease and cardiovascular disease continue to contribute substantially to poor outcomes among people living with diabetes. In Canada, adults living with diabetes are hospitalized for chronic kidney disease 2.6 times more often, end-stage kidney disease 3.9 times more often, and heart failure 3.1 times more often than adults without diabetes. Diabetes is also the leading cause of kidney disease in Canada, emphasizing the importance of early detection and appropriate screening (Public Health Agency of Canada, 2025).

It may be easy to assume that because a patient has a recent eGFR result on file, we understand their kidney health and their risk of chronic kidney disease. However, eGFR and ACR tell us different things.

• An eGFR estimates how well the kidneys are filtering blood.

• ACR identifies albumin leaking into the urine, which can be evidence of kidney damage. Excess protein in the urine is also associated with an increased risk of both kidney disease and cardiovascular disease (Alberta Health Services, n.d.). 

A person can have an eGFR that remains within a normal or relatively preserved range while also having an elevated ACR. This is why an eGFR result alone cannot provide a complete picture of kidney health.

Identifying albuminuria can also effect how a patient’s kidney and cardiovascular risks are assessed and may influence treatment decisions. The Alberta CKD Clinical Pathway recommends considering ACE inhibitors or ARBs for patients with diabetes and elevated ACR when clinically appropriate. It also recommends SGLT2 inhibitors for people with type 2 diabetes and chronic kidney disease who meet the relevant eGFR and ACR criteria (Alberta Health Services, n.d.). As eGFR may not be elevated with an elevated ACR, we may be missing patients with evidence of kidney disease that could benefit from protective medications.

So, what can primary care nurses do?

First, we can increase our own understanding of what the ACR and eGFR each measure, including the benefits and limitations of both tests. This distinction matters when patients are asked to complete an additional urine test. Without a clear explanation, a patient may see the ACR as inconvenient, unnecessary, or duplicative—particularly when they have already completed bloodwork and have been told that their kidney function looks normal.

Second, we can strengthen our understanding of the rates and consequences of kidney disease and cardiovascular disease among people living with diabetes. We already recognize these conditions as risks, and we may believe we are doing everything possible to support screening. However, if we cannot clearly explain why both parts of kidney screening matter, our patients are unlikely to understand why they should complete the additional urine test.

Encouraging patients to complete urine ACR testing—and clearly explaining why it matters—may help improve screening and support earlier identification of kidney damage before a decline in kidney filtration is apparent. It may also create opportunities for earlier risk assessment, monitoring, and kidney-protective treatment.

For Alberta primary care nurses, the Chronic Kidney Disease Clinical Pathway is a practical resource for reviewing who should be screened, interpreting eGFR and ACR together, understanding when repeat testing is required, and seeing how the results may affect medical management and referral decisions.

References

Alberta Health Services. (n.d.). Chronic Kidney Disease (CKD) Clinical Pathway.https://www.ckdpathway.ca/

Black, J. E., Campbell, D. J. T., Ronksley, P. E., McBrien, K. A., & Williamson, T. S. (2024). Screening and diagnosis of chronic kidney disease in adults living with diabetes: A retrospective cohort study using the Canadian Primary Care Sentinel Surveillance Network. Canadian Journal of Diabetes, 48(8), 487–492.e3.https://doi.org/10.1016/j.jcjd.2024.08.001

Public Health Agency of Canada. (2025). Diabetes in Canada: Health outcomes. Government of Canada. https://health-infobase.canada.ca/diabetes/outcomes.html