Frequencies and patterns of laboratory test requests from general practice: a service evaluation to inform point-of-care testing.

AIMS: The demand for test requests from general practice to laboratory services remains high. Tests performed at the point of care could reduce turnaround time and speed up clinical decision making. Replicating laboratory testing in the community would require panels of tests to be performed simultaneously, which is now approaching technological feasibility. We assessed frequencies and combinations of test requests from community settings to inform the potential future development of multiplex point-of-care panels.

METHODS: We assessed all laboratory test requests made from general practice in Oxfordshire, UK, from January 2014 to March 2017. We summarised test request frequency overall and in combination, using heatmaps and hierarchical cluster analysis. Results are also presented by age/sex subgroups. We further assessed patterns of tests requested within 7 and 14 days after an initial test request.

RESULTS: 11 763 473 test requests were made for 413 073 individuals (28% age >65). Of more than 500 test types, 62 were requested at least 5000 times, most commonly renal function tests (approximately 296 000/year), full blood count (278 000/year) and liver function tests (237 000/year). Cluster analysis additionally identified a clear grouping of tests commonly used to investigate anaemia. Follow-up test frequency was much lower than the frequency of multiple tests ordered at initial presentation.

CONCLUSIONS: The current high volume of single and combination test requests highlights an opportunity for reliable multiplex point-of-care panels to cover a core set of frequently requested tests. The impact on test use of introducing such panels to general practice requires additional research.