GPs are ordering more than three times as many tests diagnostic for their patients as they were 15 years ago as they now provide more services previously provided by hospitals and monitor more patients with chronic diseases, shows a study published in The BMJ today.

The tests are costing the NHS more than £2.8bn a year and ordering and reviewing their results has increased workload pressure in general practice, the authors say.

Using a database of patients registered with general practices, researchers at the universities of Oxford, Bristol, and Southampton looked at the change in the number of tests ordered by public methods between 1 April 2000 to 31 March 2016.

They found that between 2000/1 and 2015/16 the number of tests ordered per 10,000 person-years increased 3.3 fold from 14,869 to 49,267. This represents an 8.5% increase per year.

"Patients in 2015/16 had on average five tests per year, compared with 1.5 in 2000/1," they say. The increase in the number of tests ordered was slightly higher in men (3.4-fold increase) than in women (3.3-fold increase), and most significant in elderly patients (4.6-fold increase for patients aged over 85 years).

A total of 44 specific tests were looked at 28 laboratory tests; 11 imaging tests; and five different tests, such as spirometry (a measure of lung function), cervical smears, and electrocardiography (to record the electrical activity of the heart).

Significant rises in the number of tests ordered were seen for 40 of the 44 individual tests and across all three different test groups (laboratory, imaging and miscellaneous). The researchers suggest that the increased testing might be partly due to changes to NHS service provision.

Primary care requiring tests

For example, over the study period, GPs' ability to be able to order diagnostic tests (particularly imaging) expanded, many services were diverted from secondary to primary care requiring tests to be ordered by GPs rather than hospitals, and the Quality and Outcomes Framework, which incentivizes GPs to monitor chronic diseases using laboratory tests, was introduced.

Increased testing could be a reflection of the increasing number and duration of consultations in general practice with tests being used for "strategic, non-medical reasons," such as to reassure patients and end meetings, they add.

It could also reflect a greater expectation among patients that they should be tested as they have become more informed and been encouraged to participate in decisions about their care.