---

Background : The number of elderly people admitted through the emergency department is rapidly increasing, which has a significant and serious impact on emergency care and costs. In order to identify correctly and preventively the elderly who are at greater risk of being readmitted to the emergency wards, we examined the validity of the ISAR tool in this area.
Methods: In this correlational study, 264 elderly men and women 60 years and older who were discharged from the Emergency wards of “Vasei”, “Emdad” and “Heshmatieh” Hospitals were studied. They were selected by random sampling in 1397 and were included in the study and followed for 3 months. Data were collected using demographic questionnaire and ISAR tool and analyzed by SPSS v.19 software to evaluate the validity of the tool.
Results: The mean age of the sample group was approximately 72 years. The ISAR tool for predicting elderly re-admission one month after emergency discharge had 31% sensitivity and 88% specificity (PPV = 42%, NPV = 82%, AUC = 59%), two months after had 36% sensitivity and 85% specificity (PPV = 43%, NPV = 81%, AUC = 0.60) and three months after had 58% sensitivity and 77% specificity (PPV = 52%, NPV = 81%, AUC = 0.67).
Conclusion: Our study showed that the ISAR tool lacked validity to predict elderly re-admission in the short-term after discharge from emergency wards (1to3months).