Risk factors for resistance and MDR in community urine isolates: population-level analysis using the NHS Scotland...

Area of Science:

• Infectious Diseases
• Public Health
• Pharmacology

Background:

• Urinary tract infections (UTIs) are prevalent, with empirical antibiotic treatment posing risks for undertreating resistant infections.
• Characterizing risk factors for antibiotic resistance is crucial for effective UTI management.

Purpose of the Study:

• To identify and quantify risk factors associated with antibiotic-resistant and multidrug-resistant (MDR) community-acquired urinary isolates.
• To leverage routine, linked health data for epidemiological surveillance of antimicrobial resistance.

Main Methods:

• Utilized national patient-level data from Scotland (2012-2015), linking urine isolate surveillance with hospital activity and community prescribing records.
• Employed multivariable logistic regression to analyze associations between patient demographics, comorbidities, healthcare exposures, and resistant/MDR urinary isolates.

Main Results:

• 28% of 40,984 isolates were susceptible, 45% resistant, and 27% MDR.
• Exposure to ≥4 distinct antibiotics in the prior 6 months significantly increased MDR risk (OR 6.81).
• Cumulative antibiotic exposure (≥29 DDD) and specific agents like nitrofurantoin and trimethoprim were strongly associated with MDR, with effects persisting for up to 12 months.

Conclusions:

• This study provides the first large-scale national evidence quantifying the cumulative and sustained impact of antibiotic exposure on MDR in community urine isolates.
• Findings will inform the development of clinical decision support tools to optimize antibiotic selection for UTIs.