Longitudinal trends in laboratory test utilization at a large tertiary care university hospital in Sweden

BACKGROUND: The aim of the study was to describe and evaluate longitudinal trends in laboratory test utilization over a 7-year period from 2002 to 2008. METHOD: Retrospective study using test request data from the Clinical Chemistry and Pharmacology Laboratory at Akademiska Sjukhuset, a large tertiary care university hospital in Sweden. Changes in test utilization, charges, and expenditures during the study period were used as main outcome measures. RESULTS: Laboratory test utilization increased by over 70%, with a mean annual increase of 9.3% during the study period. After adjustment for inflation, the laboratory expenditures increased by 20.2% during the study period but represented only approximately 2.0% of the hospital's total expenditure in 2008. The test menu comprised 663 tests in 2008, an increase by 146% from 2002. The mean inflation-adjusted unit price charged per test increased from €34.9 to €37.5 during the study period. The top 10, 20, and 30 tests accounted for, on average, 46.9%, 66.9%, and 75.5% of the total test volume during the study period, and 47.8%, 66.4%, and 75.7% of the total test volume in 2008. In 2008, 10 analyses, i.e. 1.5% of the number of tests on the menu, accounted for almost half the number of generated test results. CONCLUSIONS: The total number of generated test results increased by over 70% in less than a decade. Even so, the laboratory's share of the hospital's total expenditure remained low and virtually unchanged. A very small number of tests accounted for a disproportionately large share of the total number of generated test results.