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

Background:
Substantial variation in testing rates in adults with hypertension across UK primary care suggest that patients are not receiving optimal monitoring.

Aim:
To develop a minimal set of evidence-based blood tests for adults with hypertension.

Design and Setting:
Rapid review, routine data analyses, and consensus study. Set in Primary care.

Method:
We examined the rationale and evidence for tests recommended by guidelines or used commonly in adults with hypertension using stepwise rapid evidence reviews. 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.

Results:
We identified 16 routinely ordered tests. We found consistent, 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, clotting biomarkers, calcium, ferritin, folate acid, or vitaminB12. We found good evidence that there is no benefit in routinely monitoring liver function, inflammation markers, or brain natriuretic peptide.

Conclusion:
We identified a minimal set of evidence-based blood tests to monitor adults with hypertension. This panel includes eGFR, HbA1c, potassium and sodium. 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.