Managing inappropriate requests of laboratory tests: from detection to monitoring

The main objectives of this study were to show a simple approach to detect inappropriate requests of laboratory tests and to monitor success after establishing interventions. These objectives were monitored through process and outcome indicators customized according to the type and phase of the appropriateness strategy.

Quasi-experimental design.

Based on evidence regarding laboratory test utilization differences among different geographical areas of Spain, we identified serum calcium (s-Ca) testing to be underrequested and total bilirubin (tBil) testing to be overrequested in primary care patients who undergo testing at the Public University Hospital of San Juan, in San Juan de Alicante, Alicante, Spain. Additionally, the ratio of free thyroxine (FT4) tests to thyrotropin (also called thyroid-stimulating hormone [TSH]) tests was well above the published 0.25 goal in primary care. Finally, numerous laboratory tests were overrequested in hospitalized patients due to repetitive testing. We designed and implemented a variety of strategies to correct such inappropriateness and designed different indicators to monitor the intervention success over time.

After implementation of the different strategies, the absolute number of s-Ca tests increased. The number of tBil tests in primary care, and numerous other tests repeated too frequently in hospitalized patients, decreased. The FT4/TSH indicator goal was reached and maintained over time. Regarding the outcome indicators, the strategy of reducing tBil tests in primary care and reducing the aggregate of unnecessary tests in hospitalized patients resulted in savings of $3543.80 and $9825.50, respectively, from January 2012 to December 2014. The s-Ca strategy, from November 2011 to December 2014, detected 62 subjects' primary hyperparathyroidism at a cost of $137.80 per case.

The study demonstrates a simple approach to detect inappropriate requests of laboratory tests, and how to assess the potential success of interventions using process and outcome indicators.