Is female gender as harmful as bacteria? analysis of hospital admissions for urinary tract infections in elderly patients.

Abstract

Urinary tract infections (UTIs) are common bacterial diseases. We related diagnosis of UTIs based on International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) and in-hospital mortality (IHM) in a cohort of hospitalized elderly subjects. All patients admitted between 2000 and 2013 to the general hospital of Ferrara, in northeast Italy, with ICD-9-CM code of UTIs were included. IHM was the main outcome, and age, sex, type of microorganism, sepsis, and Charlson comorbidity index (CCI) based on ICD-9-CM, were also analyzed. The total sample included 2,266 patients (1,670 women, 73.7%) with UTIs and identification of a cultural organism. Mean age was 81.7±7.5 years (range, 65-103). One hundred and sixteen (5.1%, of whom 34.5% were male and 65.5% were female) cases developed sepsis, and 84 (3.7%, of whom 45.2% were male, 54.8% were female) had a fatal outcome. Nonsurvivors had lower prevalence of IVUs due to Escherichia coli (53.6 vs. 71.7%, p<0.001) and higher prevalence of UTIs due to Pseudomonas aeruginosa (19 vs 7.1%, p<0.001). Moreover, non-survivors developed more frequently sepsis (31% vs. 4.1%, p<0.001), and had higher CCI (2.81±2.43 vs. 2.21±2.04, p=0.011). IHM was independently associated, in decreasing order of odds ratios (ORs), with sepsis (OR 10.3; 95% confidence interval [95% CI] 6.113-17.460, p<0.001), P. aeruginosa infection (OR 2.541; 95% CI 1.422-4.543, p=0.002), female gender (OR 2.324; 95% CI 1.480-3.650, p<0.001), CCI (OR 1.103; 95% CI 1.005-1.210, p=0.038), age (OR 1.034; 95% CI 1.002-1.066, p=0.036), and E. coli infection (OR 0.5; 95% CI 0.320-0.780, p=0.002). In a large sample of elderly patients hospitalized for UTIs in a single center in northeastern Italy, apart the development of sepsis, IHM was much more dependent on pathogen and female gender than comorbidity index and age.