Differences in Routine Laboratory Ordering Between a Teaching Service and a Hospitalist Service at a Single Academic...

Studies have shown that the overutilization of laboratory tests ("labs") for hospitalized patients is common and can cause adverse health outcomes. Our objective was to compare the ordering tendencies for routine complete blood counts (CBC) and chemistry panels by internal medicine residents and hospitalists.

This observational study included a survey of medicine residents and hospitalists and a retrospective analysis of labs ordering data. The retrospective data analysis comprised patients admitted to either the teaching service or nonteaching hospitalist service at a single hospital during 2014. The survey asked residents and hospitalists about their practices and preferences on labs ordering. The frequency and timing of one-time and daily CBC and basic chemistry panel ordering for teaching service and hospitalist patients were obtained from our data warehouse. The average number of CBCs per patient per day and chemistry panels per patient per day was calculated for both services and multivariate regression was performed to control for patient characteristics.

Forty-four of 120 (37%) residents and 41 of 53 (77%) hospitalists responded to the survey. Forty-four (100%) residents reported ordering a daily CBC and chemistry panel rather than one-time labs at patient admission compared with 22 (54%) hospitalists (P < 0.001). For CBCs, teaching service patients averaged 1.72/day and hospitalist service patients averaged 1.43/day (P < 0.001). For basic chemistry panels, teaching service patients averaged 1.96/day and hospitalist service patients averaged 1.78/day (P < 0.001). Results were similar in multivariate regression models adjusting for patient characteristics.

Residents' self-reported and actual use of CBCs and chemistry panels is significantly higher than that of hospitalists in the same hospital. Our results reveal an opportunity for greater supervision and improved instruction of cost-conscious ordering practices.