Not All Falls Are Equal: Risk Factors for Unplanned Readmission in Older Patients After Moderate and Severe Injury-A National Cohort Study.

OBJECTIVES: Readmission after acute care is a significant contributor to health care costs, and has been proposed as a quality indicator. Our earlier studies showed that patients aged ≥55 years who are injured by falls from heights of ≤0.5 m were at increased risk for long-term mortality, compared to patients by high-velocity blunt trauma (higher fall heights, road injuries, and other blunt trauma). We hypothesized that these patients are also at higher risk of readmission, compared to patients injured by high-velocity mechanisms.

DESIGN AND MEASURES: Competing risks regression (all-cause unplanned readmission or death) was performed.

SETTING AND PARTICIPANTS: Data for 5671 patients from the Singapore National Trauma Registry data who were injured from 2011-2013 and aged 55 and over were matched to Ministry of Health admissions data. The registry uses standardized conversion metrics to convert patient histories to fall heights.

RESULTS: Patients injured after a low fall were more likely to be readmitted to a hospital, compared to those sustaining injuries by high-velocity blunt trauma. On competing risks analysis, low fall [subdistribution hazard ratio (SHR) 1.52, 95% confidence interval (CI) 1.20-1.93, P < .01], Charlson Comorbidity Score (CCS≥3 relative to CCS = 0, SHR 1.46, 95% CI 1.04-2.04, P = .03), and Modified Frailty Index (MFI≥3 relative to MFI = 0, SHR 1.98, 95% CI 1.44-2.72, P < .001) were associated with higher risk of 30-day readmission. Rehabilitation was associated with reduced 30-day (SHR 0.64, 95% CI 0.48-0.86, P < .001) and 1-year (SHR 0.84, 95% CI 0.72-0.99, P = .04) readmission.

CONCLUSIONS/IMPLICATIONS: Our study sheds light on the interpretation of trauma data in aging populations. The detailed fall height information in our registry makes it uniquely placed to facilitate understanding of the paradoxical finding that injuries sustained by low-energy falls are higher risk than those sustained by higher-velocity mechanisms. Low-fall patients should be prioritized for rehabilitation and postdischarge support. The proportion of low-fall patients in a trauma registry should be included in the factors considered for benchmarking.