Score can predict readmission risk

A prediction score can identify before discharge the likelihood of a potentially avoidable 30-day readmission, a new study suggests.

In a retrospective cohort study, researchers analyzed all patient discharges from medical services at Brigham and Women's Hospital in Boston between July 2009 and June 2010. They identified potentially avoidable 30-day readmissions using a computerized algorithm based on administrative data and analyzed these cases to develop a prediction score that could be used prospectively to identify factors that place patients at high risk for readmission. Results were published online March 25 by JAMA Internal Medicine.

Readmissions were considered to be unavoidable if they were planned or if they were unforeseen due to newly developed conditions unrelated to known diseases during the index hospitalization. Avoidable readmissions were related to a previously coded medical condition or resulted from a treatment complication. The researchers looked at readmissions to Brigham and Women's as well as Massachusetts General Hospital and Faulkner Hospital; all three are affiliated with the Partners HealthCare network.

Among 10,731 eligible discharges, 2,398 (22.3%) were followed by a 30-day readmission. Of these, 879 (8.5% of all discharges) were identified as potentially avoidable. Researchers randomly divided these potentially avoidable admissions and those not followed by a 30-day readmission (n=8,333) into a derivation and validation set to determine the prediction score.

The prediction score identified seven independent factors, referred to with the acronym HOSPITAL: Hemoglobin at discharge, discharge from an Oncology service, Sodium level at discharge, Procedure during the index admission, Index Type of admission, number of Admissions during the last 12 months and Length of stay. The HOSPITAL score had good calibration and fair discriminatory power (C statistic, 0.71).

It was surprising that none of the most frequent comorbidities in readmitted patients were retained as a factor in the final model, the researchers noted. “The hypothesis that comorbidities or causes of admission do not matter as much as illness severity or clinical instability is attractive and has intuitive appeal,” they wrote. The HOSPITAL score, which can be used for all patients regardless of their main admission cause, enables physicians to target intensive transitions-of-care interventions to those who might benefit the most from them, they concluded.

However, an invited commenter noted that more research is needed on how to most effectively help patients at risk of readmission, since currently recommended interventions are resource intensive. One intervention that doesn't seem to work is having inpatient clinicians communicate directly with outpatient clinicians at discharge, another study in the March 15 JAMA Internal Medicine found. Fifty-four percent of inpatient clinicians don't attempt to directly communicate with the outpatient physician during discharge at all, and even among those who did, no reduction in readmissions was associated with direct communication, the study found.