Understanding Healthcare Provider Preferences for Ordering Respiratory Cultures to Diagnose Ventilator Associated Pneumonia: A Discrete Choice Experiment

Objective: Ventilator-associated pneumonia (VAP) can be overdiagnosed on the basis of positive respiratory cultures in the absence of clinical findings of pneumonia. We determined the perceived diagnostic importance of 6 clinical attributes in ordering a respiratory culture to identify opportunities for diagnostic stewardship.

Design: A discrete choice experiment presented participants with a vignette consisting of the same "stem" plus variations in 6 clinical attributes associated with VAP: chest imaging, oxygenation, sputum, temperature, white blood cell count, and blood pressure. Each attribute had 3-4 levels, resulting in 32 total scenarios. Participants indicated whether they would order a respiratory culture, and if yes, whether they preferred the bronchoalveolar lavage or endotracheal aspirate sample-collection method. We calculated diagnostic utility of attribute levels and relative importance of each attribute.

Setting And Participants: The survey was administered electronically to critical-care clinicians via a Qualtrics survey at a tertiary-care academic center in the United States.

Results: In total, 59 respondents completed the survey. New radiograph opacity (utility, 1.15; 95% confidence interval [CI], 0.99-1.3), hypotension (utility, 0.88; 95% CI, 0.74-1.03), fever (utility, 0.76; 95% CI, 0.62-0.91) and copious sputum (utility, 0.75; 95% CI, 0.60-0.90) had the greatest perceived diagnostic value that favored ordering a respiratory culture. Radiograph changes (23%) and temperature (20%) had the highest relative importance. New opacity (utility, 0.35; 95% CI, 0.17-0.52) and persistent opacity on radiograph (utility, 0.32; 95% CI, 0.05-0.59) had the greatest value favoring bronchoalveolar lavage over endotracheal aspirate.

Conclusion: Perceived high diagnostic value of fever and hypotension suggest that sepsis vigilance may drive respiratory culturing and play a role in VAP overdiagnosis.