Impact of point-of-care testing for white blood cell count on triage of patients with infection in the remote Northern Territory of Australia

Abstract

In Australia's Northern Territory (NT), acute infections are highly prevalent within Indigenous remote communities and difficulties in diagnosing the aetiology of infection are exacerbated by limited access to diagnostic tests. The objective of this study was to investigate the clinical effectiveness of point-of-care (POC) testing for total and 5-part differential white blood cell (WBC DIFF) counts for the triage of patients with possible acute infection. The HemoCue WBC DIFF POC device was introduced into 13 remote health clinics over a 6 month period. A retrospective clinical audit of patient cases meeting the selection criteria for three acute infections (sepsis, respiratory infection and appendicitis) were examined by four registrars in duplicate; one with POC test results available and the other with POC test results removed to determine if WBC DIFF results changed or assisted in patient triage. The number of changed outcomes provided a preliminary cost-benefit analysis. Sixty (23%) patient cases met the selection criteria for the clinical effectiveness analysis. POC test results changed the triage decision for 24 (41%) patients, of which 20 (34%) led to the prevention of an unnecessary medical retrieval and four (7%) indicated the patient had an acute infection which required a medical retrieval. POC test results assisted decision making for a further 13 (22%) patients. Cost savings related to avoiding unnecessary medical retrievals were estimated to be AU$481,440. Extrapolated NT-wide cost savings are projected to be AU$5.33 million per annum. POC testing for WBC DIFF counts aided clinical decision making for triaging patients with three common acute infections.

Keywords: White blood cell count; infection; point-of-care testing; remote health; triage.