Clinical decision rule to identify febrile young girls at risk for urinarytract infection

Objective: To develop a clinical prediction rule to identify febrile young girls needing urine culture for evaluation of urinary tract infection (UTI) . Design: Prospective cohort study. Setting: Urban children's hospital emergency department. Patients: All girls younger than 2 years (N = 1469) presenting to the emerg ency department with fever (temperature greater than or equal to 38.3 degre es C) and without an unequivocal source of fever during a 12-month period. Main Outcome Measures: The outcome of interest was UTI, defined as a cathet erized urine culture with pure growth of 10(+) colonies/mL or greater. Cand idate predictors included demographic, historical, and physical examination variables. Clinical prediction rules were developed using multiple logisti c regression after screening variables for univariate association and relia bility. Results: The presence of 2 or more of the following 5 variables-less than 1 2 months old, white race, temperature of 39.0 degrees C or higher, fever fo r 2 days or more, and absence of another source of fever on examination-pre dicted UTI with a sensitivity of 0.95 (95% confidence interval, 0.85-0.99) and a specificity of 0.31 (95% confidence interval, 0.28-0.34). In the stud y population, with an overall prevalence of UTI of 4.3%, the positive predi ctive value of a score of 2 or more was 6.4% and the negative predictive va lue of a score of less than 2 was 0.8%. Conclusion: Using this clinical decision rule, a strategy of obtaining urin e cultures from girls younger than 2 years with a score of 2 or more would lead to identification of 95% of children with UTI and elimination of 30% o f unnecessary urine cultures.