Main problem There 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.

Methods We 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.

Results There 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.

Conclusions In 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 summary Patients 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.

The authors have declared no competing interest.

This study was supported by National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research (NIHR201616). This research was supported by the NIHR Applied Research Collaboration West (ARC West). The views expressed in this article are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. The funder was not involved in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

For the part of the study that used routine data, the authors were provided with pseudonymised Clinical Practice Research Datalink (CPRD) data under licence from the MHRA and NIHR. The protocol (21_001671) for this study was approved on 21/12/2021 by the Independent Scientific Advisory Committee (ISAC), the independent body that approves use of CPRD data. All data used in this study are routinely collected and anonymised and thus consent was not required. CPRD have approval to collect and disseminate anonymised data to approved researchers for the benefit of public health under IRAS 242149.

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The data from rapid reviews and the consensus meetings that support the findings of this study are available within this paper and supplementary files. A small part of this study is based on data from the Clinical Practice Research Datalink (CPRD) obtained under licence from the MHRA and NIHR. The data are provided by patients and collected by the NHS as part of their care and support. CPRD data can be accessed via the MHRA: https://www.cprd.com/