Diagnostic Stewardship Intervention to Reduce Inappropriate Antibiotic Use for Urinary Tract Infections in Primary Care

Background: Urinary tract infections (UTIs) account for more than 10 million ambulatory visits annually in the United States and are the third-leading cause of outpatient antibiotic prescriptions. Gram-negative urinary pathogens collected from outpatients across all regions of the United States now exhibit antimicrobial resistance levels that exceed thresholds recommended for empiric treatment of UTIs. Accurate urine cultures are essential for guiding antibiotic therapy. Midstream clean-catch (MSCC) urine collection is the gold standard for obtaining urine specimens, yet contamination rates in outpatient settings range from 46% to 55% in the recent studies. Contamination leads to incorrect diagnoses, unnecessary antibiotic use, increased resistance, and higher healthcare costs. Prior interventions aimed at reducing contamination have had mixed results and lacked stakeholder engagement and effective educational modalities.

Significance: This study addresses Goal 3 of the National Action Plan for Combating Antibiotic-Resistant Bacteria and CDC priorities by improving diagnostic accuracy and reducing inappropriate antibiotic use. Our approach empowers frontline staff and targets a neglected area of outpatient diagnostic stewardship. Urine culture contamination is common, wasteful, and harmful, particularly for pregnant patients who are routinely screened for bacteriuria. Contamination obscures true infection or leads to overtreatment, increasing risks for antimicrobial resistance, adverse drug reactions, and healthcare costs. Our intervention will improve patient care and reduce waste of laboratory resources.

Innovation and Impact: The proposed research is innovative because it places nurses and medical assistants at the forefront of antimicrobial stewardship in primary care. The investigators will develop a bilingual, multicultural educational intervention that includes an animated instructional video and a pictorial flyer. These materials will provide step-by-step guidance for proper MSCC urine collection and will be designed with input from patients, nurses, and medical assistants to ensure cultural competence and clarity for individuals with low literacy. This approach represents a departure from previous interventions, which lacked stakeholder engagement and failed to reduce contamination rates effectively. By incorporating stakeholder feedback and using engaging visual formats, the investigators aim to create an intervention that is acceptable, appropriate, and feasible for diverse patient populations.

Specific Aims: Aim 1: Iteratively develop a bilingual, multicultural educational intervention to reduce urine contamination, with stakeholder and expert input. The intervention will include an animated instructional video and a flyer with pictorial instructions that will provide step-by-step guidance to patients for collecting an MSCC urine sample. Aim 2: Perform a pilot study to assess and improve the intervention's acceptability, appropriateness, and feasibility using mixed methods. The investigators will use a sequential explanatory design that includes a quantitative survey and qualitative interviews with stakeholders (patients, nurses, and medical assistants). Aim 3: Test the effectiveness of the intervention at reducing urine culture contamination via a randomized controlled trial. The investigators hypothesize that patients who are randomized to receive the intervention versus usual care will have lower culture contamination rates (primary outcome), fewer urinary antibiotic prescriptions (secondary outcome), and fewer contaminated urinalyses (secondary outcome). Investigators will also study intervention fidelity, usability, and patient satisfaction using mixed methods research.

Methodology: The study will be conducted in two safety-net and one private primary care clinics. The investigators will use a randomized controlled trial with parallel groups to compare the intervention to usual care. Eligible participants will be adults aged 18 years or older who are asked to provide a urine sample for culture or urinalysis. Patients with indwelling urinary catheters or those unable to view the video or read the flyer in English or Spanish will be excluded. Randomization will occur at the patient level using a secure electronic system managed through REDCap. Participants assigned to the intervention group will view the animated video and flyer in their preferred language before urine collection. Men will receive materials tailored for men, and women will receive materials tailored for women. Participants in the control group will receive usual care without additional education. The primary outcome is the proportion of contaminated urine cultures, defined as mixed flora, growth of non-uropathogens, or growth of three or more uropathogens. Secondary outcomes include antibiotic prescribing within seven days of urine culture results and contamination of urinalyses, defined as more than ten squamous epithelial cells per microscopic field. The investigators will also assess implementation results through exit interviews and surveys. The sample size for the trial is 252 patients (126 per arm). Data will be collected from electronic medical records, patient surveys, and qualitative interviews. All data will be securely stored and de-identified for analysis.

Next Steps/Implementation: If the intervention proves effective, future work will focus on disseminating the educational tools to other settings, such as emergency departments and long-term care facilities. This project will provide a scalable, resource-efficient approach to improving diagnostic accuracy, reducing unnecessary antibiotic use, and advancing antimicrobial stewardship in outpatient care.