Teaching Hospitals Consistently Order More Lab Tests Per Patient

A new study validates the long-held assumption that intensity of care is consistently higher at teaching hospitals, compared to nonteaching hospitals. Patients in Texas admitted to major teaching hospitals with two common conditions receive significantly more laboratory tests per day, compared to similar patients at nonteaching hospitals even after controlling for illness severity, length of stay, and patient demographics, according to a study published Nov. 13 in JAMA Internal Medicine. In an environment with increased focus on value-based care and appropriate test utilization, the authors say that studying cultural factors in the training environments that may lead to increased use of laboratory tests is essential.

Findings Applied to A Single Case

The authors offer the following illustration:

Patient: A 42-year-old African American man with Medicaid insurance coverage presenting to the emergency department with community-acquired pneumonia.

Hospitalization: A 4-night hospital stay with an illness severity of 2.

Laboratory Testing: Based on the study results, if this patient were admitted to a nonteaching hospital, he would receive 10 laboratory tests per day during his hospitalization, for a total of 40 laboratory tests versus if he were admitted to a major teaching hospital he would receive 13 laboratory tests per day, for a total of 52 laboratory tests, representing a 30 percent increase in use of laboratory testing.

Using a large statewide all-payer database, the researchers identified hospitalizations with a primary diagnosis of bacterial pneumonia (n = 24,118) or cellulitis (n = 19,211; from Jan. 1, 2014, to June 30, 2015) across 11 major teaching hospitals, 12 minor teaching hospitals, and 73 nonteaching hospitals in Texas each with 100 or more hospitalizations for each condition. These diagnoses were selected in part due to the fact that specialized laboratory testing is generally not required for these conditions and that they are cause for admission at both teaching and nonteaching hospitals.

The researchers found that the mean number of laboratory tests per day varied significantly by hospital type and was highest for major teaching hospitals for both conditions (bacterial pneumonia: major teaching hospitals, 13.21 versus 8.92 at nonteaching hospitals; cellulitis: major teaching hospitals, 10.43 versus 7.29 at nonteaching hospitals). This association held for all levels of illness severity for both conditions, except for patients with cellulitis with the highest illness severity level. The size of the effect amounted to approximately 3.6 additional laboratory tests per day for pneumonia and 2.6 additional laboratory tests per day for cellulitis. Hospitals that had more laboratory tests ordered for patients with pneumonia also had more laboratory tests ordered for patients with cellulitis.

Of the 11 major teaching hospitals, eight were above the mean number of laboratory tests performed across all hospitals for pneumonia and seven were above the mean number of laboratory tests performed across all hospitals for cellulitis.

“Our data also show that patients with pneumonia at major teaching hospitals are sicker, perhaps leading to learned behaviors by trainees of ordering more laboratory tests,” write the authors led by Victoria Valencia, from University of Texas at Austin. “Perhaps higher rates of testing are justified for a substantial fraction of patients in teaching hospitals, but this behavior may then spill over to less acutely ill patients…. If this phenomenon exists it could complicate generalized efforts to reduce testing at academic medical centers and could even lead to harm if there is an overall nontargeted reduction in testing.”

Takeaway: This study confirms a widespread pattern of increased laboratory test ordering in teaching hospitals, even for common conditions. In an environment with increased focus on value-based care, targeted test reduction interventions need to ensure sicker patients are receiving needed tests, but that less severely ill patients are not receiving unnecessary testing.