Definition of Recurrent Urinary Tract Infections in Women: Which One to Adopt?

OBJECTIVES: The aim of this study was to systematically review the various definitions of recurrent urinary tract infection (RUTI) recommended by experts and specialty societies cited in biomedical literature.
METHODS: A systematic review of RUTI in women was conducted using MEDLINE, EMBASE, and PubMed between 1966 and 2016 according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Statement. Twenty-five publications were selected for inclusion in this analysis.
RESULTS: From review of included publications, 14 definitions of RUTI were obtained. Each source was searched for a textual definition of RUTI as well as presence or absence of specific key elements including urinary symptoms, colony forming unit count, bacterial species, number of UTIs per year, interval time between infections and a negative intervening culture. All data were reviewed by 2 separate investigators. The definition of RUTI was found highly variable in the literature. The tallying of key elements in included definitions suggests that a minimum RUTI definition should include urinary symptoms, urine culture colony forming unit/mL threshold, differentiation of bacterial persistence versus reinfection by bacterial species, and number of UTIs per year.
CONCLUSIONS: This review of major RUTI definition recommendations by expert individuals and specialty societies underlines the lack of uniformity and the need for a more robust and generally agreeable RUTI definition for use in clinical and academic practice.