Editor's Choice: Adverse outcomes in older adults attending emergency departments: a systematic review and meta-analysis of the Identification of Seniors At Risk (ISAR) screening tool

Background: older adults are frequent users of emergency services and demonstrate high rates of adverse outcomes following emergency care. Objective: to perform a systematic review and meta-analysis of the Identification of Seniors At Risk (ISAR) screening tool, to determine its predictive value in identifying adults >= 65 years at risk of functional decline, unplanned emergency department (ED) readmission, emergency hospitalisation or death within 180 days after index ED visit/hospitalisation. Methods: a systematic literature search was conducted in PubMed, EMBASE, CINAHL, EBSCO and the Cochrane Library to identify validation and impact analysis studies of the ISAR tool. A pre-specified ISAR score of >= 2 (maximum score 6 points) was used to identify patients at high risk of adverse outcomes. A bivariate random effects model generated pooled estimates of sensitivity and specificity. Statistical heterogeneity was explored and methodological quality was assessed using validated criteria. Results: thirty-two validation studies (n = 12,939) are included. At >= 2, the pooled sensitivity of the ISAR for predicting ED return, emergency hospitalisation and mortality at 6 months is 0.80 (95% confidence interval (CI) 0.70-0.87), 0.82 (95% CI 0.74-0.88) and 0.87 (95% CI 0.75-0.94), respectively, with a pooled specificity of 0.31 (95% CI 0.24-0.38), 0.32 (95% CI 0.24-0.41) and 0.35 (95% CI 0.26-0.44). Similar values are demonstrated at 30 and 90 days. Three heterogeneous impact analysis studies examined the clinical implementation of the ISAR and reported mixed findings across patient and process outcomes. Conclusion: the ISAR has modest predictive accuracy and may serve as a decision-making adjunct when determining which older adults can be safely discharged.