Evidence-based blood tests for monitoring adults with chronic kidney disease stage 3 in primary care: rapid review, routine data analysis, and consensus study

Main problemThere is substantial UK variation regarding which blood tests people receive for routine monitoring of stage 3 chronic kidney disease (CKD3) in primary care, suggesting that many people are not receiving optimal care. This study aimed to develop evidence-based testing panels for CKD3. MethodsWe considered blood tests used commonly or recommended in CKD3 guidelines, identifying the rationale for each test and then applying a series of filtering questions (e.g. can the GP do anything in response to an abnormal result?) to identify whether tests should be included in the testing panel. Each question was answered by stepwise rapid evidence reviews. A consensus group, consisting of patient representatives and clinicians, voted on whether tests should be included based on the evidence. If tests had insuficient evidence, additional evidence was collected through rapid reviews or routine data analysis and voted on in a second consensus meeting. ResultsThere was good evidence for, and consensus supporting, routinely testing eGFR, haemoglobin, and HbA1c; and not routinely testing urea, lipids, vitamin B12, ferritin, folate, liver function, potassium, sodium, vitamin D, calcium, thyroid function, clotting, C-reactive protein, erythrocyte sedimentation rate, and B-type natriuretic peptide. Once on stable treatment, patients on statins do not need additional monitoring tests and patients on ACE-1 or ARB only need potassium monitoring. ConclusionsIn contrast to current guidelines, our findings suggest that CKD3 patients should only be routinely ofered eGFR, HbA1c and haemoglobin monitoring. Implementing these recommendations could reduce testing variation in CKD3 patients and reduce costs. Lay summaryPatients with chronic kidney disease are often followed up by their GP. At regular monitoring appointments, blood and urine tests are done to determine whether a change in management is needed, such as adjusting medications. However, which tests are needed at these appointments is not standardised and depending on where you live, the tests that you get may difer because of diferences in local practices. Here, we reviewed the evidence for blood tests that are currently used for patients with chronic kidney disease, and we found that for many tests there is little or no evidence that they are beneficial. We only found good evidence for regular testing of eGFR to test renal function, HbA1c to detect diabetes, and haemoglobin to detect anaemia. Avoiding unnecessary tests is important to prevent overdiagnosis, overtreatment, patient anxiety, and to ensure that resources are focused on efective, evidence-based care.