Who Gets a Laboratory Test in Hospital, Why, and How Often? A Retrospective Observational Study of 4 Australian...

Laboratory providers are challenged with the need to deliver improvements in the efficiency and effectiveness of laboratory services. Initiatives have been set to reduce the inappropriate use of tests; however, empirical evidence about the rate and frequency of laboratory tests in hospitals has not been widely available. This study used data linkage techniques to investigate laboratory test use among Australian inpatients.

A retrospective observational study was conducted across 3 metropolitan and 1 rural hospital, all serviced by a single laboratory provider. Data for all admitted inpatients between January 2008 and December 2013 were extracted and linked to determine the proportion of admissions with a laboratory test, number of tests per admission, and time to first test.

This study included 521480 admissions. Of these, 83.7% had a pathology test. Newborns and neonates had the lowest percentage of admissions with tests (35.2%), whereas admissions for diseases and disorders of the hepatobiliary system and pancreas had the highest (97.5%). Patients had a median of 12 tests per admission. Patients 80-84 years of age had the highest rate of tests per admission (median, 19; interquartile range, 9-36). Forty-nine percent of patients' first tests occurred within 2 h of admission, increasing to 69.9% within 4 h.

The vast majority of patients admitted to hospital received laboratory tests. Higher laboratory testing rates were observed with increasing age. These findings can be used to define and compare laboratory testing among inpatients and help identify sources of variation in laboratory testing.