Developing Benchmarking Metrics for Appropriate Ordering of Vitamin D, Thyroid Testing, and Iron Workups

Laboratory stewardship programs are increasingly adopted to enhance test utilization and improve patient care. Despite their potential, implementation within complex healthcare systems remains challenging. Benchmarking metrics helps institutions compare their performance against peers or best practices. However, the application in laboratory stewardship is underrepresented in the literature.

The PLUGS (Patient-centered Laboratory Utiliazation Guidance Services) Informatics Working Group developed guidelines to address common test utilization issues. Metrics were based on data that are easily retrievable and calculable. Three key benchmarks were chosen for a pilot study: the ratio of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D test orders, the ratio of thyroid-stimulating hormone (TSH) to free thyroxine (FT4) test orders, and the percentage of iron workup orders after an initial low mean corpuscular volume (MCV). Institutions analyzed their own data and we established optimal benchmarks through inter-laboratory comparisons.

Nine laboratories evaluated vitamin D testing, with 2 implementing stewardship interventions beforehand. A benchmark of 50:1 was established, where a higher ratio indicates intentional ordering of 1,25-dihydroxyvitamin D. Nine laboratories evaluated thyroid testing, with 3 implementing interventions. The benchmark of 3.5:1 was established, with a higher ratio suggesting judicious TSH ordering. Seven laboratories evaluated iron workups, proposing a benchmark of 50% as a starting metric. Intervention guidelines were provided for laboratories below the benchmarks to promote improvement.

Benchmarking metrics provide a standardized framework for assessing and enhancing test utilization practices across multiple laboratories. Continued collaboration and refinement of benchmarking methodologies is essential in maximizing the impact of laboratory stewardship programs on patient safety and resource utilization.