CJEM Infographic: The PERIL Rule – Paramedics assessing Elders at Risk for Independence Loss

In Infographics, Medical Concepts by Alvin Chin1 Comment

This month’s CJEM Infographic summarizes the PERIL Rule – a clinical decision instrument designed to help paramedics to identify patients who are at risk for adverse events [cite num=”1″]. The summarized study was published in the most recent version of the Canadian Journal of Emergency Medicine.

Featured in the latest CanadiEM infographic, this study by Lee et al1 set out to develop a clinical prediction rule to help paramedics identify high risk older adults. The methodology involved identifying 43 predictor variables in three systemic reviews.2–4 The authors defined the composite endpoint as a repeat visit to the ED, hospitalization, and/or death within 30 days of the EMS encounter. Paramedics were trained to use this checklist to assess patients >65 years old in their home after responding to a 911 call. Four significant independent predictors associated with the primary outcome measure were isolated.

The four-item PERIL rule was derived and performed better than clinical judgement (AUC 0.62 vs. 0.56, p=0.02). Adherence for the PERIL rule was also higher than the alternate Identifying Seniors at Risk (ISAR) tool. Of note however, the ISAR tool has been found only to have poor to fair validity5 related to revisiting the ED and hospital readmission.

This study aimed to provide a new tool for paramedics to use to help identify high risk older adults. The result was a simple, easy to use prediction rule with high adherence rate that has possible future use following further validation.


Lee J, Verbeek P, Schull M, et al. Paramedics assessing Elders at Risk for Independence Loss (PERIL): Derivation, Reliability and Comparative Effectiveness of a Clinical Prediction Rule. CJEM. 2016;18(2):121-132. [PubMed]
Aminzadeh F, Dalziel W. Older adults in the emergency department: a systematic review of patterns of use, adverse outcomes, and effectiveness of interventions. Ann Emerg Med. 2002;39(3):238-247. [PubMed]
Grief C. Patterns of ED use and perceptions of the elderly regarding their emergency care: a synthesis of recent research. J Emerg Nurs. 2003;29(2):122-126. [PubMed]
McCusker J, Karp I, Cardin S, Durand P, Morin J. Determinants of emergency department visits by older adults: a systematic review. Acad Emerg Med. 2003;10(12):1362-1370. [PubMed]
Yao J, Fang J, Lou Q, Anderson R. A systematic review of the identification of seniors at risk (ISAR) tool for the prediction of adverse outcome in elderly patients seen in the emergency department. Int J Clin Exp Med. 2015;8(4):4778-4786. [PubMed]
Alvin is currently a PGY5 in the FRCP EM program at McMaster University. He serves as Director of Design for CanadiEM and has interests in knowledge translation and health innovation.