Why Test (2020 - 2023)

We know rates of testing in primary care are rising. Unnecessary blood tests are important as they could lead to anxiety for patients, increased workload for GPs and increased costs for the NHS. Ensuring test results are followed up and actioned is important for patient safety.

PACT members collected anonymised data on blood tests for over 2,500 patients from 57 GP practices in England, Scotland, Wales and Northern Ireland, to find out why blood tests are requested in primary care, who requests blood tests, and what happens with the results.



Watch our video to learn more about Why Test

Chief investigator

Dr Jessica Watson 

GP and Academic Clinical Lecturer

Ethics approval

University of Bristol

Faculty of Health Sciences Research Ethics Committee

Funding and support

National Institute for Health and Care Research

Applied Research Collaborative West

National Institute for Health and Care Research

Research Capability Funding (RCF) from Bristol, North Somerset and South Gloucestershire CCG

Why Test timeline

Protocol development

Sep 2020

Ethics approval

Apr 2021

Recruitment start

Feb 2022

Data collection start

Feb 2022

Data analysis start

Sep 2022

Benchmarking data

Aug 2022

Final publication

Jun 2023

Key findings

  • 6.2% of test results led to a new diagnosis or confirmation of a diagnosis, and abnormal or borderline results were common with only around a quarter (26.6%) of patients having results in the normal range.

  • A quarter of tests may have been partially or fully unnecessary when reviewed retrospectively by another clinician.

  • Around half of tests (48%) did not lead to any change in management or reassurance, 13.4% led to further blood tests or repeat blood tests, and 2.7% led to further radiology tests.

  • The most common reasons for testing were symptoms (43.2%), monitoring of existing disease (30.1%), and monitoring of existing medications (10%).

  • Only around half of tests were requested by GPs, reflecting the multidisciplinary nature of primary care. On average 4.5 tests were requested simultaneously per patient.

57 collaborating practices

Publications and communications