Clinical question: What is the relationship between duration of intravenous (IV) antibiotic therapy and treatment failure in infants <6 months of age hospitalized with urinary tract infections (UTIs)?
Background: There is an inadequate evidence base to drive decisions regarding duration of IV antibiotic therapy in young infants hospitalized with UTIs. Documented variability exists in length of stay (LOS) and resource utilization for these infants, which might be a direct result of practice variation with respect to IV therapy.
Study design: Retrospective cohort study.
Setting: Twenty-four freestanding children’s hospitals.
Synopsis: The Pediatric Health Information System (PHIS) administrative database was used to identify healthy infants <6 months of age admitted with a primary or secondary diagnosis of UTI or pyelonephritis from 1999 to 2004 to participating hospitals. Duration of IV therapy was defined as a dichotomous variable with three days (short course: three days) selected because it was the median length of therapy. Treatment failure was defined as readmission within 30 days.
More than 12,300 records were analyzed. Male gender, neonatal status, black race, Hispanic ethnicity, nonprivate insurance, severity of illness, known bacteremia, known genitourinary tract disorders, and specific hospital were independently associated with increased likelihood of long-course (four days) therapy.
Unadjusted analysis initially revealed that long-course therapy was significantly associated with a higher rate of treatment failure. After multivariate (to include propensity scores) adjustment, a significant association between treatment duration and failure was no longer identified. Treatment failure association with known genitourinary abnormalities and higher severity of illness remained.
A significant limitation of this study is the potential for multivariate analysis to fail to mitigate a bias toward sicker patients receiving longer duration of antibiotic therapy and, thus, having a higher likelihood of treatment failure. In addition, the greater question of when IV antibiotics (and hospital admission) are indicated in this population was not addressed by the study design.
Nonetheless, the data likely support a limited utility to long-course IV antibiotic therapy in this population. The study also adds to the evolving picture of considerable and widespread variation in physician practice.
Bottom line: Short-course IV therapy for infants with UTIs does not increase risk of treatment failure.
Citation: Brady PW, Conway PH, Goudie A. Length of intravenous antibiotic therapy and treatment failure in infants with urinary tract infections. Pediatrics. 2010;126(2):196-203.
Reviewed by Pediatric Editor Mark Shen, MD, medical director of hospital medicine at Dell Children’s Medical Center, Austin, Texas.
