A comparison of pathology usage in three New South Wales public hospitals.

Data on pathology testing in New South Wales public hospitals are extremely limited. Pathology laboratory billing files and hospital admissions and transfer files were used to obtain data on the pathology testing frequency and cost of testing at three New South Wales public hospitals. Data were also extracted that allowed a comparison of test ordering frequency and cost of testing for various groups of admitting specialists. A high degree of similarity was found in the test ordering patterns at each hospital with 16 common tests or test groups in the top 20 tests or test groups at each hospital. These 16 tests or test groups accounted for 78, 82 and 88% of the total pathology expenditure at each hospital. The total cost of pathology per occupied bed day was found to be A$26.23, A$34.63 and A$44.66 at each hospital and represented 5.5, 5.2 and 6.8% of the total cost per occupied bed day, respectively, at each hospital. Variation was found between hospitals in the cost per occupied bed day for surgery, medicine, obstetrics and gynaecology and paediatrics. Three major reasons for the variations in pathology costs were identified as variations in outpatient loads, variations in test ordering patterns among medical practitioners and casemix.