Risk factors for recurrent urinary tract infections in a cohort of patients with primary vesicoureteral reflux.
BACKGROUND
Knowledge of risk of urinary tract infection (UTI) recurrence in vesicoureteral reflux (VUR) can help clinicians make therapeutic decisions. The aim of this retrospective cohort study was to identify risk factors associated with recurrent urinary tract infection in children with VUR. In addition, a risk score that might predict the chance of UTI recurrence was also proposed.


METHODS
Between 1970 and 2007, 740 patients were diagnosed with VUR and were systematically followed up at a single tertiary Renal Unit. Recurrent UTI was defined as more than 1 episode during follow-up. A binary logistic regression model was applied to identify variables independently associated with recurrent UTIs.


RESULTS
During follow-up, information was obtained on 58,856 person-months. Recurrent UTIs occurred in 120 (16.2%) patients. The overall incidence rate of UTI was 8.4 episodes per 1000 person-months (95% CI, 7.7, 9.2). After adjustment by multivariable analysis, 5 variables were independent predictors of recurrent UTI: UTI as clinical presentation, age < 6 months, female gender, dysfunctional elimination syndrome, and severe grade of reflux. The risk for recurrent UTI was classified as low in 24% of children, medium in 42%, and high in 34%. UTI incidence rates per 1000 person-months were 4.3 (95% CI, 3.2, 5.6), 7.9 (95% CI, 6.7, 9.1), and 11.3 (95% CI, 9.9, 12.8) for low-, medium-, and high-risk groups, respectively.


CONCLUSIONS
The prediction model of recurrent UTI allows an early recognition of patients at risk for long-term morbidity and might contribute to the formulation of therapeutic strategies.
Pediatric Nephrourology Unit, School of Medicine, Brazilian National Research Council (CNPq), Hospital das Clínicas, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Cristiane S
CS
Dias
Jose Maria P
JM
Silva
Jose Silverio S
JS
Diniz
Eleonora M
EM
Lima
Renata C
RC
Marciano
Louisie G
LG
Lana
Ana Luiza L
AL
Trivelato
Marcela S
MS
Lima
Ana Cristina
AC
Simöes e Silva
Eduardo A
EA
Oliveira
D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000453:epidemiology*; D014718:Vesico-Ureteral Reflux / Q000150:complications*