Higher patient-to-physician ratios associated with worse outcomes in the emergency department.

Abstract

Objective: To investigate the association between patient-to-physician ratios, a measure of physician workload, and various patient outcomes in the emergency department (ED).

Methods: This retrospective observational study analyzed 406,220 ED visits at a tertiary care center in Taipei, Taiwan, between January 2015 and December 2019. The dynamic patient-to-physician ratio was calculated using minute-by-minute data to reflect real-time physician workload. Multivariable regression models, adjusted for potential confounders, assessed the association between this ratio and 7-day mortality (primary outcome), ED length of stay, waiting time, and medical expenses (secondary outcomes). Generalized additive models were used to explore non-linear relationships. Sensitivity analyses evaluated alternative mortality timeframes, missing data handling, and a simplified patient-to-physician ratio. External validation was performed using data from two additional hospitals.

Results: Higher patient-to-physician ratios were significantly associated with increased odds of 7-day mortality. Compared to ratios of less than 10, the adjusted odds ratios were 1.46 (95% CI 1.16, 1.83) for ratios between 10 and 19, 1.79 (95% CI 1.43, 2.25) for ratios between 20 and 29, and 1.95 (95% CI 1.53, 2.49) for ratios of 30 and above. Similar trends of increased risk were observed for longer ED length of stay, prolonged waiting times, and higher medical expenses. Sensitivity analyses using alternative mortality timeframes, missing data handling methods, and the simplified patient-to-physician ratio yielded consistent results, supporting the main findings.

Conclusions: Higher patient-to-physician ratios are associated with worse outcomes for ED patients. Our findings suggest that maintaining ratios below 10 may be ideal for optimizing care quality, while ratios exceeding 20 pose significant risks to patients.