P17 Baseline characteristics, disease progression rates and risk factors among female patients with uncomplicated urinary tract infection in England
Authors: Wilcox Mark , Heaton Dave , Mulgirigama Aruni , Joshi Ashish V , Chirikov Viktor , Gibbons Daniel C , Webb David , Marston Xiaocong L , Alexander Myriam , Mitrani-Gold Fanny S 
Published: August 2023

Background and Objectives

Uncomplicated urinary tract infection (uUTI) is a common, usually community-acquired bacterial infection. Little is known about risk factors for disease progression (defined here as hospitalization for Escherichia coli sepsis, bacteraemia or acute pyelonephritis) among patients with uUTI. We report the baseline demographic and clinical characteristics among female uUTI patients with/without disease progression in England.

Methods

This retrospective cohort study utilized anonymized patient data from 1 January 2018 to 31 December 2019 from the Clinical Practice Research Datalink (CPRD) database linked to English Hospital Episode Statistics data. Eligible patients were female, aged ≥12 years, had received an index diagnosis for a community-acquired uUTI, had ≥12 months’ CPRD data history, and had received ≥1 oral antibiotic within ±5 days of diagnosis. Patients were excluded if they had complicated UTI or complicating comorbidities, were hospitalized/visited an accident and emergency department 28 days prior to index or had received IV antibiotics as initial therapy. uUTI episodes were defined as the 28 days post-index (Figure 1). Descriptive patient (demographic and clinical characteristics), region and practice-level characteristics in the 12 month baseline period are presented for patients with/without disease progression. Figure 1.Study design. HES, Hospital Episode Statistics.

Results

Among 116793 female patients with a uUTI, 207 were hospitalized for E. coli sepsis, bacteraemia or acute pyelonephritis within 28 days of index (0.2%). The mean age (SD) for patients with/without progression was 67.3 (20.2) and 52.9 (21.1), respectively; 81% and 34% of patients with/without progression were ≥50 years old. Imbalances were observed for comorbid burden, baseline medications, initial presentation (i.e. home visit requirement) and prior antimicrobial treatment (Table 1). Few regional or practice-level differences were apparent (Table 1). Table 1.Patient (demographic and clinical characteristics), region and practice-level variable distribution between uUTI patients without and with hospitalization for uUTI disease progressionVariable description/Statistic or categoryPatient subgroupsno disease progression (N=116586)disease progression (N=207)N%N%Patient-level Age at diagnosis, years, mean (SD)52.9 (21.1)–67.3 (20.2)– Age at diagnosis  ≥12 to &lt;167110.600  ≥16 to &lt;301986117157.2  ≥30 to &lt;401668214136.3  ≥40 to &lt;501518413115.3  ≥50 to &lt;6024512214220  ≥65396363412661 Age at diagnosis (pooled)  &lt;5052438453919  ≥50396363416881 Charlson comorbidity index, mean (IQR)0 (0, 0)–0 (0, 1)– Charlson comorbidity category  0959448213465  118007155828  223002125.8  ≥33350.3&lt;5 Race/ethnicity, N (%)  Asian or Asian British51614.462.9  Black or Black British32872.862.9  Chinese or other group19951.7&lt;5-  Ethnic group not recorded22781204321  White41340357335 Number of hospital admissions in prior year, mean (IQR)0 (0, 0)–0 (0, 0)– Number of A&E attendances in prior year, mean (IQR)0 (0, 1)–0 (0, 1)– Smoking status  Non-smoker725466211957  Ex-smoker27084236230  Smoker16956152613 Menopausal status, yes34072296029 Obesity, yes13858123316 Mild/moderate renal impairment, yes22621.9104.8 Controlled diabetes (HgA1C &lt;6.5/7%), yes24512.1146.8 History of recurrent uUTI, yes49374.2115.3 Prior antimicrobial treatment (any), yes702746015072 Cumulative antimicrobial prescriptions, median (IQR)1 (0, 2)–&lt;5–Region-level Quintiles of index of multiple deprivation  Q1 (least deprived)26869234220  Q223597203919  Q322273193818  Q422085194622  Q5 (most deprived)21762194220 Rural-urban area classification  Rural15416133014  Urban1011708717786Practice-level Practice size  Small (&lt;8000 patients)30783265627  Medium (8000–11000 patients)25377224421  Large (&gt;11000 patients)604265210752Percentage values do not add up to 100% for ethnicity as these data were not available for all patients and mixed ethnicity is not shown due to limited interpretability.A&E, accident and emergency; HgA1C, glycated haemoglobin; Q, quintile.

Conclusions

Hospitalization following uUTI is rare in this study, however, at a population level, this still affects a large number of female patients. Coding limitations meant potentially linked admissions (e.g. falls and confusion) could not be identified. Hospitalizations appear to be driven by patient factors rather than regional differences or practice patterns. The role of these putative risk factors for disease progression will be explored further via multivariable logistic regression analysis.