Predicting survival in cancer patients with and without 30-day readmission of an unplanned hospitalization using a deficit accumulation approach

Background For cancer patients with an unplanned hospitalization, estimating survival has been limited. We examined factors predicting survival and investigated the concept of using a deficit-accumulation survival index (DASI) in this population. Methods Data were abstracted from medical records of 145 patients who had an unplanned 30-day readmission between 01/01/16 and 09/30/16. Comparison data were obtained for patients who were admitted as close in time to the date of index admission of a study patient, but who did not experience a readmission within 30 days of their discharge date. Our survival analysis compared those readmitted within 30 days versus those who were not. Scores from 23 medical record elements used in our DASI system categorized patients into low-, moderate-, and high-score groups. Results Thirty-day readmission was strongly associated with the survival (adjusted hazard ratio [HR] 2.39; 95% confidence interval [CI], 1.46-3.92). Patients readmitted within 30 days of discharge from index admission had a median survival of 147 days (95% CI, 85-207) versus patients not readmitted who had not reached median survival by the end of the study (P < .0001). DASI was useful in predicting the survival; median survival time was 78 days (95% CI, 61-131) for the high score, 318 days (95% CI, 207-426) for the moderate score, and not reached as of 426 days (95% CI, 251 to undetermined) for the low-score DASI group (P < .0001). Conclusions Patients readmitted within 30 days of an unplanned hospitalization are at higher risk of mortality than those not readmitted. A novel DASI developed from clinical documentation may help to predict survival in this population.