A total of 1014 studies were identified through database searches, of which 154 were selected for full-text review and 91 were included for data extraction. For these studies, data were extracted from primary papers. Additional relevant studies were identified from conference abstract searches and article bibliographies. In total, 118 records were included for data extraction (Fig. 1). Of the 118 studies, 101 reported data on incidence, prevalence, mortality, or causative pathogen proportions. Most of the included studies minimized bias regarding exposure measurement and outcome measure (Supplementary Material, Figure S-1).

PRISMA diagram. ECCMID, European Congress of Clinical Microbiology and Infectious Diseases; IDSA, Infectious Diseases Society of America; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SLR, systematic literature review

Incidence and prevalence rates of cUTI differed because of inconsistent definitions of cUTI, the anatomic location of the UTI, and varying patient populations [3, 12]. A total of 29 studies [8, 14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41] reported the incidence and/or prevalence of cUTI, including 20 [8, 23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41] that reported specifically on CAUTI. One US study reported the prevalence for both catheter-associated and non-catheter-associated cUTI [8]. Of the 29 included studies, 21 were from the US [8, 16,17,18,19,20,21,22, 29,30,31,32,33,34,35,36,37,38,39,40,41], 2 were multinational [14, 42], 2 each were from Italy [24, 25] and Spain [27, 28], and 1 each was from France [15] and Japan [26] (Table 1).

One study reported the incidence rate specifically for AP [43]. This multicenter retrospective study, conducted in the US, evaluated the incidence of AP in pregnancy and its perinatal outcomes (N = 546,092 pregnancies). The prevalence of prenatal AP among all pregnant women was 0.5%, with an incidence rate of 5.3 cases per 1000 births [43]. Another relatively small US study of adults with UTI (N = 269) seen in an outpatient clinic reported that 15 patients (5.6% of UTI cases and 10.9% of cUTI cases) had pyelonephritis [20].

Escherichia coli, Klebsiella species (spp.), and other organisms such as Proteus and Enterobacter spp. are the pathogens most frequently associated with cUTIs [2]. A total of 52 studies reported the etiology of infection, of which 35 were from the inpatient setting [21, 24, 25, 28, 35, 39, 40, 42, 44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,