BACKGROUND:Identification of the characteristics that put hospitalized children at high risk of deterioration may help to target patients whose physiologic status should be intensively monitored for signs of deterioration, and reduce unnecessary monitoring in patients at very low risk. Previous studies have evaluated vital sign‐based early warning scores to detect deterioration that has already begun.OBJECTIVE:To develop a predictive score for deterioration using non‐vital sign patient characteristics in order to risk‐stratify hospitalized children before signs of deterioration are detectable.DESIGN:Case‐control study.SETTING:A 460‐bed children's hospital.PATIENTS:Cases (n = 141) were children who deteriorated while receiving care on non‐intensive care unit (non‐ICU) inpatient units. Controls (n = 423) were randomly selected.MEASUREMENTS:The exposures were complex chronic conditions, other patient characteristics, and laboratory studies. The outcome was clinical deterioration, defined as cardiopulmonary arrest, acute respiratory compromise, or urgent ICU transfer.RESULTS:The 7‐item score included age <1 year, epilepsy, congenital/genetic conditions, history of transplant, enteral tube, hemoglobin <10 g/dL, and blood culture drawn in the preceding 72 hours. We grouped the patients into risk strata based on their scores. The very low‐risk group's probability of deterioration was less than half of baseline risk. The high‐risk group's probability of deterioration was more than 80‐fold higher than the baseline risk.CONCLUSIONS:We identified a set of characteristics associated with clinical deterioration in children. Used in combination as a score, these characteristics may be useful in triaging the intensity of monitoring and surveillance for deterioration that children receive while hospitalized on non‐ICU units. Journal of Hospital Medicine 2012;