Systematic Review of the Global Literature on Uncomplicated Recurrent Urinary Tract Infections: Underscoring Major Heterogeneity

INTRODUCTION: Urinary tract infections (UTI) are common infections affecting over 60% of women and often become recurrent (rUTI). Despite their prevalence, research on rUTIs is limited and results are heterogenous due to varying definitions and populations. This systematic review examines global literature on uncomplicated rUTI and assesses differences in data based on geographic region. METHODS: Databases PubMed, Embase, WHO Global Index Medicus, and SciELO were searched for the keywords and/or MESH terms for recurrent and UTI, 2000- 2023. Studies were restricted to females ≥18 with uncomplicated rUTIs. Studies were excluded if they did not provide a definition for rUTI or did not cite/report an estimate for rUTI prevalence. The review was registered in PROSPERO and conformed to PRISMA. RESULTS: The search yielded 2,947 studies of which 124 were included (Table 1). Most studies were conducted in Europe (41%) or North America (39%), were prospective (52%), at tertiary centers (49%) and included all age groups (60%). Public institutions were the most common in North America (67%) while multi-center and public institutions were equally frequent in Europe (39% each). The most common definition for rUTI was 2 UTI/6m or 3 UTI/1y (62%). Regardless of study location, most studies cited prevalence estimates for rUTI from U.S.-based populations. Convenience samples were used for 91% of studies and sample sizes were: 30% n<50, 29% n=50-99, 22% n=100-199, 36% n≥200. CONCLUSIONS: This study represents the first formal investigation of the global literature base on uncomplicated rUTI. Studies on rUTIs are globally of small scale and definitions used for rUTI are heterogeneous. More studies are needed to ascertain the true prevalence of rUTI outside of North America and Europe.