A quarter of blood tests done in general practice may be unnecessary, say primary care researchers who found half would not lead to any change in management.
An audit of blood tests for more than 2,500 patients at 57 GP practices in the UK also found abnormal or borderline results are common with only 26% of patients receiving results in the normal range.
The research led by the University of Bristol found just 6% of test results led to a new diagnosis or confirmation of diagnosis, they reported in the British Journal of General Practice.
Study lead Dr Jessica Watson, a GP and NIHR clinical lecturer in general practice said rates of blood testing had increased over the past two decades but no one had looked at who was ordering tests and why and what the outcomes were.
The Why Test? Study also presented at the Society of Academic Primary Care conference in Brighton has implications for helping patients have ‘realistic expectations’ of test results, she added.
It showed the commonest reasons for testing in primary care were investigation of symptoms (43%), monitoring of existing disease (30%), monitoring of existing medications (10% and follow up of previous abnormalities (7%).
Around 1.5% of tests looked at in the study were done simply because the patient requested it. Half were requested by GPs ‘reflecting the multidisciplinary nature of primary care’, the researchers said.
The analysis was done by 57 clinicians taking part in the Primary Care Academic CollaboraTive (PACT). They found that on review about a quarter of tests were partially or fully unnecessary.
They also found that 48.8% did not lead to change in management or reassurance and 13% led to further or repeat blood tests.
The ‘cascade effect’ of a test leading to more tests, imaging, appointments and referrals needs to be put in the context of an already overstretched health service, they noted.
While the findings are unlikely to surprise practicing clinicians, there are important implications ‘given the move to offer all patients in England with access to their blood test results via the NHS App’, Dr Watson said.
More work is needed to understand how patients will interpret borderline results – which happened with high frequency in the analysis, the research team added.
‘If patients see that their test results are outside the reference range it could potentially trigger alarm,’ they concluded.
‘The results have important implications for how primary care clinicians talk to patients about blood tests, to ensure that they have a better of understanding of why a test may or may not be necessary and realistic expectations of the role of blood tests in their care,’ said Dr Watson.
‘Many tests don’t lead to a diagnosis or change in treatment, although they may still be important to rule something out or provide reassurance.’
She added: ‘There is also a need for better evidence to inform judgements on whether a test is necessary or not, as sometimes this judgement is only possible with hindsight when test outcomes are known.
‘Unnecessary tests could lead to increased anxiety for patients, increased workload for GPs and increased costs for the NHS. We need better evidence to help us ensure that patients get the right test at the right time.’