Evaluating hospital readmission rates after discharge from inpatient rehabilitation

Daras, L. C., Ingber, M. J., Carichner, J., Barch, D., Deutsch, A., Smith, L. M., ... Andress, J. (2017). Evaluating hospital readmission rates after discharge from inpatient rehabilitation. Archives of Physical Medicine and Rehabilitation. DOI: 10.1016/j.apmr.2017.07.008

OBJECTIVE: To examine facility-level rates of all-cause, unplanned hospital readmissions for 30 days following discharge from inpatient rehabilitation facilities (IRFs).

DESIGN: Using an observational design, we analyzed Medicare claims in order to develop an all-cause, risk-adjusted hospital readmission measure.

SETTING: We used national Medicare inpatient claims and enrollment data for Medicare beneficiaries who were discharged from IRFs in 2013-2014 and met specific inclusion criteria (1,166 IRFs).

PARTICIPANTS: Medicare fee-for-service beneficiaries (n = 567,850 patient-stays).

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURE: The outcome is all-cause, unplanned hospital readmission rates for IRFs. We adapted previous risk-adjustment and statistical approaches used for acute care hospitals to develop a hierarchical logistic regression model that estimates a risk-standardized readmission rate for each IRF. The IRF risk-adjustment model takes into account patient demographics, hospital diagnoses and procedure codes, function at IRF admission, comorbidities, and prior hospital utilization. We produced distributions of observed and risk-standardized readmission rates and estimated confidence intervals to make statistical comparisons relative to the national average. We also analyzed the number of days from IRF discharge until hospital readmission.

RESULTS: The national observed hospital readmission rate by 30 days post-IRF discharge was 13.1%. The mean IRF unadjusted readmission rate was 12.4% (SD = 3.5%) and the mean risk-standardized rate was 13.1% (SD = 0.8%). The C-statistic for our risk-adjustment model was 0.70. Nearly three-quarters (73.4%) of IRFs had readmission rates that were significantly different from average. The mean number of days to readmission was 13.0 (SD = 8.6) days and varied by rehabilitation diagnosis.

CONCLUSIONS: Our results demonstrate the ability to assess IRFs' post-discharge hospital readmission rates and the ability to discriminate between IRFs with higher- and lower-than-average hospital readmission rates.