Abstract
BACKGROUND: This study evaluated the effectiveness of replacing chlorhexidine-based oral care with toothbrushing and reinforcing head-of-bed elevation (HOBE) for the prevention of ventilator-associated pneumonia (VAP) in real-world practice using an interrupted time-series (ITS) analysis. METHODS: This quasi-experimental study was conducted in eight adult intensive care units (ICUs) of a 2,734-bed tertiary care hospital in Seoul, South Korea. The interventions, implemented in May 2023, included replacing chlorhexidine-based oral care with toothbrushing and strengthening HOBE adherence. ITS analysis was performed to assess the impact of the intervention on monthly VAP incidence rates from August 2022 through November 2024. RESULTS: Adherence to HOBE increased significantly from 84 to 95% after the intervention (P < 0.001). During the study period, 144 VAP cases occurred: 66 cases during 16,849 device-days in the pre-intervention period (3.9 per 1,000 device-days) and 78 cases during 32,185 device-days in the post-intervention period (2.4 per 1,000 device-days). ITS analysis demonstrated a significant decrease in both the level and trend of VAP incidence following the intervention (level change coefficient: -1.66, 95% confidence interval [CI]: -3.07 to -0.25, P = 0.029; trend change coefficient: -0.25, 95% CI: -0.45 to -0.06, P = 0.015). Sensitivity analyses using alternative transition windows and negative binomial models showed directionally consistent post-intervention declines, whereas estimates were attenuated and not statistically significant in the fully covariate-adjusted ITS model. CONCLUSIONS: Implementation of toothbrushing-based oral care combined with reinforced HOBE was followed by lower VAP incidence in the primary ITS analysis, supporting the feasibility of these aspiration-prevention measures in routine ICU practice.