The PARIS score can reliably predict 7-day all-cause mortality for both acute medical and surgical patients: an international validation study

Background: We believe errors in the risk assessment of acutely ill patients occur because only vital signs without concurrent functional capacity are considered. We, therefore, developed the PARIS risk score based on blood pressure, age, respiratory rate, loss of independence and oxygen saturation. Aim: Validation of the PARIS score in four independent cohorts from three countries. Methods: Retrospective cohort study of acutely ill patients admitted to hospitals in Denmark, Ireland and Uganda. Vital signs and functional capacity (registered as ability to stand or walk or get into bed unaided) was recorded upon arrival. Patients were followed up for 7 days (Denmark and Ireland) or until discharge (Uganda) and mortality recorded. The discriminatory power (ability to identify patients at increased risk) was determined using area under the receiver operating characteristics curve (AUROC) and calibration (precision) using Hosmer-Lemeshow goodness of fit test. Results: Out of 14 447 patients, 327 (2.3%) died within 7 days: median age was 59 (39-75) years and 7458 (51.8%) were female. Seven-day mortality increased from 0.3% with a score of 0-26.7% with a score of 5. The score's AUROC as 0.833 [95% confidence interval (95% CI) 0.811-0.856], 0.817 (95% CI 0.792-0.842) and 0.894 (95% CI 0.813-0.974) for all patients, medical patients and surgical patients, respectively. However, except for surgical patients, calibration of the score was poor. Conclusion: The PARIS score can identify both high and low risk acutely admitted medical and surgical patients, but calibration was poor for medical patients.