Evidence-based blood tests for monitoring adults with hypertension in primary care: rapid review, routine data analyses, and consensus study

BackgroundSubstantial variation in testing rates in adults with hypertension across UK primary care suggest that patients are not receiving optimal monitoring. AimTo develop a minimal set of evidence-based blood tests for adults with hypertension. DesignRapid review, routine data analyses, and consensus study. SettingPrimary care. MethodWe developed an initial list of tests which were recommended by guidelines or used commonly. We created filtering questions to examine the rationale of each test. To answer each question, we performed stepwise rapid reviews of evidence cited by guidelines, high-quality studies, systematic reviews, and individual studies. A consensus group, including clinicians and patients, voted to include or exclude each test in the testing panel based on the evidence. If there was no consensus (>80%), additional evidence was sought through rapid reviews or analyses of primary care records, which was subject to further voting. ResultsWe identified 16 tests that are routinely ordered for people with hypertension. We found consistent and good evidence that eGFR to detect chronic kidney disease and HbA1c to detect diabetes is beneficial for patients. We found no or inconsistent evidence of the benefit of routinely measuring lipids, electrolytes, haemoglobin, thyroid function tests, clotting tests, calcium, ferritin, folate acid, or vitamin B12. We found good evidence that there is no benefit in routinely monitoring liver function, inflammation markers, or brain natriuretic peptide. ConclusionWe identified a minimal set of evidence-based tests that should be offered to adults with hypertension. Implementing these recommendations could reduce harms associated with unwarranted variation in care. Further research is needed to clarify the role of tests with inconsistent evidence and determine the optimal frequency of testing. Key messagesO_ST_ABSWhat is already known on this topicC_ST_ABSThere is substantial variation in the use of blood tests to monitor people with hypertension suggesting that many patients are not receiving optimal care. Over-testing can cause patient harm, including patient anxiety, unnecessary downstream tests, referrals, and overdiagnosis, as well as wasting limited NHS resources. What this study addsWe have developed a minimal testing panel for patients with hypertension based on the best available evidence and a consensus process. The panel includes eGFR to screen for chronic kidney disease, HbA1c to screen for diabetes mellitus, potassium for patients on ACE inhibiters and angiotensin II receptor blockers. How this study might affect research, practice or policy - summarise the implications of this studyUnnecessary testing could be prevented if guidelines and local protocols recommended minimal testing sets and made clear additional tests should only be added if clinically indicated. Future research needs to address optimal testing intervals and test thresholds.