46: Impact of reported allergies in treatment of women with recurrent urinary tract infection

Abstract

Recurrent UTI (rUTI) is a common, costly condition often requiring Female Pelvic Medicine and Reconstructive Surgery care. Identifying appropriate treatment begins with knowledge of patients' reported allergies, which may be inaccurate. This is problematic as inappropriate antibiotic use is linked to multi-drug resistant organisms, a public health threat affecting quality of life and healthcare cost. This study aims to evaluate the impact of reported antibiotic allergies on antibiotic selection and cost in treatment of rUTI. We queried our institution’s electronic medical record to identify female patients aged 25-85 with a documented allergy history from 2007 to 2017. Patients were grouped into allergy profiles, sorted by prevalence. Eight rUTI scenarios were developed using the most prevalent organisms and sensitivities from our institution’s 2018 antibiogram. Treatment of a patient in each allergy profile was driven by AUGS Best Practice guidelines for each rUTI scenarios. Differential costs of rUTI treatment for an individual in each allergy profile were computed by adding the price of 3 courses of acute treatment and 6 months of prophylaxis compared to an individual with no reported antibiotic allergies. Differential total costs of treatment for all reported antibiotic allergies were computed by summating the cost differences in treating individuals, multiplied by 19% (rUTI prevalence) across all rUTI scenarios. 969,679 patients were identified and sorted into 11 allergy profile categories. 75.04% of patients reported allergy to no antibiotics, 10.3% to β-Lactams, 4.18% to sulfa, and 3.24% to β-Lactams and sulfa. A first-line treatment and prophylactic therapy for each rUTI scenario was available regardless of reported allergy. Fosfomycin, the most expensive at $97.74 per packet, was the only first-line option for rUTI with P. mirabilis resistant to sulfa. Otherwise fosfomycin was only necessary for acute infection if the allergy profile included sulfa or nitrofurantoin. For 6 months of prophylaxis, nitrofurantoin and fosfomycin were the most expensive at $208.01 and $1,632.00, respectively. These were the only options available for patients with reported allergies to both β-Lactams and sulfa for any rUTI scenario. Allergy to β-Lactams and sulfa incurred a $1.1-11.3 million cost difference compared to a population without antibiotic allergies in all scenarios except an ESBL E. coli UTI resistant to trimethoprim/sulfamethoxazole (Table 1). Total differential cost for all reported antibiotic allergies ranged from $1.9-48.2 million. Accurate allergy reporting is crucial to fighting the antibiotic resistance crisis. Treatment costs for rUTI are negatively impacted by reported allergies to β-Lactams, sulfa, and nitrofurantoin. Efforts to de-label inaccurate reported allergies should be considered to help prevent multi-drug resistance and reduce healthcare costs.