External validation of the 80+ score and comparison with three clinical scores identifying patients at least 75 years old at risk of unplanned readmission within 30 days after discharge

Abstract

AIM OF THE STUDY A potentially avoidable readmission is an unplanned readmission occurring within 30 days of discharge. As 20% of hospitalised elderly patients are rehospitalised as an unplanned readmission, it is necessary to identify with a clinical score those patients who are at risk of readmission and need discharge interventions as a priority. The main objective of this study was to externally validate and compare the 80+ score with the three other scores predicting the risk of unplanned readmission. METHODS We conducted a retrospective case-control study using a clinical data warehouse. The study included patients hospitalised between 1 September 2014 and 31 October 2015 in an 800-bed university hospital. We included patients aged 75 and over. Cases were readmitted at the emergency department within 30 days after the index discharge. Controls were not readmitted as an emergency within 30 days. Four clinical scores (80+ score, LACE index, HOSPITAL score, TRST) were externally validated. Discrimination of the scores was assessed by calculating the area under the receiver operating characteristic curves (AUC). Calibration was assessed with a Hosmer-Lemeshow χ2 test. RESULTS We included 438 patients. For discrimination, the 80+ score, the LACE index, the HOSPITAL score and the TRST had AUCs of 0.506 (95% confidence interval [CI] 0.413–0.546), 0.534 (95% CI 0.459–0.591, 0.517 (95% CI 0.466–0.598) and 0.589 (95% CI 0.524–0.654), respectively. The Hosmer-Lemeshow χ2 tests had p-values of 0.44, 0.43, 0.11 and 0.49, respectively. CONCLUSION In our study, the 80+ score was externally validated and showed less favourable discrimination than the three other scores in this population.

Keywords

• elderly
• clinical score
• unplanned readmission
• external validation