Role of attending practice variability in prone positioning initiation: A retrospective cohort study

BACKGROUND: Prone positioning is underused, despite mortality benefits. Prior studies highlight that patient-independent factors may influence prone positioning rates, but attending-specific contributions are unknown.

RESEARCH QUESTION: Does significant variability in prone positioning rates exist among attending physicians?

STUDY DESIGN AND METHODS: This is a retrospective cohort study of 514 adults receiving mechanical ventilation in a tertiary-care medical or surgical ICU from January 1, 2015, through June 30, 2024. Inclusion criteria included Pa_O2 to F_IO2 ratio of ≤ 150 with F_IO2 of ≥ 60% and positive end-expiratory pressure of ≥ 5 cm H₂O within 0 to 36 hours and 36 to 72 hours of intubation. The primary outcome was prone positioning within 72 hours of intubation or 24 hours of meeting prone positioning criteria. We hypothesized that attending variability was a significant predictor of prone positioning. We fit a mixed-effects logistic regression model to evaluate attending-level variability in prone positioning use, adjusting for 6 potential patient-centered prone positioning barriers and facilitators (age, BMI, COVID-19 status, code status, Pa_O2 to F_IO2 ratio, and vasopressor use) and ICU location (medical or surgical).

RESULTS: Among 514 patients eligible for prone positioning, 87 patients (17%) underwent prone positioning. Significant attending-level variability in prone positioning was noted among the 48 attendings included in the analysis, with risk- and reliability-adjusted rates ranging from 14.9% to 74.2% and a median OR among attending physicians of 2.6 (95% CI, 1.7-5.2). This effect size was associated more strongly with prone positioning than a 30-mm Hg decrease in Pa_O2 to F_IO2 ratio. Even among patients with clinical documentation of ARDS on the day of prone positioning eligibility, the median OR among attending physicians was 2.4 (95% CI, 1.5-7.3). Additional patient factors predicting prone positioning included COVID-19 status, code status, and Pa_O2 to F_IO2 ratio.

INTERPRETATION: Our results show that large variation in prone positioning practices exists among attending providers, and future work should consider attending-focused and system-wide interventions as potential novel targets to improve prone positioning rates.

National Heart, Lung, and Blood Institute

Anna K Barker, Emily A Harlan, Meeta Prasad Kerlin, Thomas S Valley, Michael W Sjoding