Validation of the Risk Instrument for Screening in the Community (RISC) among Older Adults in the Emergency Department

Abstract

Although several short-risk-prediction instruments are used in the emergency department (ED), there remains insufficient evidence to guide healthcare professionals on their use. The Risk Instrument for Screening in the Community (RISC) is an established screen comprising three Likert scales examining the risk of three adverse outcomes among community-dwelling older adults at one-year: institutionalisation, hospitalisation, and death, which are scored from one (rare/minimal) to five (certain/extreme) and combined into an Overall RISC score. In the present study, the RISC was externally validated by comparing it with different frailty screens to predict risk of hospitalisation (30-day readmission), prolonged length of stay (LOS), one-year mortality, and institutionalisation among 193 consecutive patients aged ≥70 attending a large university hospital ED in Western Ireland, assessed for frailty, determined by comprehensive geriatric assessment. The median LOS was 8 ± 9 days; 20% were re-admitted <30 days; 13.5% were institutionalised; 17% had died; and 60% (116/193) were frail. Based on the area under the ROC curve scores (AUC), the Overall RISC score had the greatest diagnostic accuracy for predicting one-year mortality and institutionalisation: AUC 0.77 (95% CI: 0.68-0.87) and 0.73 (95% CI: 0.64-0.82), respectively. None of the instruments were accurate in predicting 30-day readmission (AUC all <0.70). The Overall RISC score had good accuracy for identifying frailty (AUC 0.84). These results indicate that the RISC is an accurate risk-prediction instrument and frailty measure in the ED.