VCOM Carolinas Research Day 2023

Clinical Studies

Retrospective Analysis of Outpatient Prescribing Patterns for Uncomplicated Cystitis in Premenopausal Women with and without an Allergy to Guideline-Recommended Antimicrobials Amber Stroupe, DO 1,2 ; Jaime Foushee, PharmD, BCPS, BCCCP 1 ; Shannon Smith, DO 2 ; Darcy A Davis OMS-III 1 ; Samantha Rikabi, OMS-III 1 ; Miles Lane, Statistician 2 1 Edward Via College of Osteopathic Medicine, Carolinas Campus, Spartanburg, South Carolina; 2 Spartanburg Regional Healthcare System, Spartanburg, South Carolina

Abstract # CLIN-2

Introduction Introduction

Methods

Results

Results

Table 4 . Primary Outcome

Figure 1 . Consort Diagram for the Target Population 496 encounters identified using ICD-10 codes N30.0 - acute cystitis without hematuria; N39.0 - urinary tract infections; R30.0 - dysuria n=313 had exclusion criteria Complicated UTI or pyelonephritis n=183 met inclusion criteria

Background information: • Over 50% of women will experience one urinary tract infection (UTI) in their lifetime, and approximately 10% of women will have UTI annually 1 • It is essential for physicians to appropriately select antibiotics for the management of suspected UTIs given the implications of inappropriate antibiotic prescribing practices, including but not limited to increased antimicrobial resistance within common UTI pathogens • The most recent Infectious Diseases Society of America (IDSA) guidelines for the treatment of uncomplicated cystitis provide preferred and alternative antimicrobial therapy recommendations, where not contraindicated due to allergy history or availability ( Table 1 ) Objective: To determine if premenopausal women 18 to 50 years of age with uncomplicated cystitis who have an allergy to a guideline-recommended antimicrobial agent are less likely to receive guideline recommended treatment compared to women without an allergy Hypothesis: Premenopausal women with an antimicrobial allergy are less likely to receive a guideline recommended antimicrobial for uncomplicated cystitis compared to those without an allergy Table 1 . IDSA Antimicrobial Recommendations for Acute Uncomplicated Cystitis 2

Primary Result Has Antimicrobial Allergy

Yes n = 40

No n = 143

p-value 0.001 1

Received Guideline Recommended Therapy

Yes No

33 (82%) 7 (18%)

140 (98%)

3 (2.1%) Guideline recommended antimicrobials: β -Lactam, fluoroquinolone, nitrofurantoin, TMP-SMX 1 Fisher's exact test

Female, ages 18-50, diagnosis of acute uncomplicated cystitis, at least one documented UA, prescribed antimicrobial therapy

• A total of 496 patient encounters were screened for inclusion, of which 183 met inclusion criteria ( Figure 1 ) • Demographic and clinical characteristics were similar between patients with and without antimicrobial allergies ( Table 2 ), except for age where a difference was seen between groups • Antimicrobial allergies were noted in 40 patients, most frequently to β -lactams (60%), followed by TMP-SMX (22%), nitrofurantoin (12%), and fluoroquinolones (5%) ( Table 3 ) • Primary outcome: Patients without an antimicrobial allergy were significantly more likely to receive a guideline-recommended therapy than those with an allergy (98% vs. 82%, p=0.001) ( Table 4 ) • Secondary outcomes: • No statistical difference was found in the secondary analysis of patients with or without an allergy to the preferred antimicrobials (nitrofurantoin and TMP-SMX) receiving guideline recommended therapy (86% vs. 95%, p = 0.2) ( Table 5 ) • No statistical difference was found between those with or without an allergy to TMP-SMX receiving guideline-recommended therapy (78% vs. 95%, p=0.079) ( Table 6 )

Tables 5 and 6 . Secondary Outcomes

Secondary Result 1 Has Antimicrobial Allergy to Preferred Antimicrobial*

Secondary Result 2 Has Antimicrobial Allergy to TMP-SMX

Yes n = 9

No n = 174

Yes n = 14

No n = 169

p-value 0.079 1

p-value

Received Guideline Therapy

Empiric Treatment Recommendations

Received Guideline Therapy

0.17 1

Yes No

7 (78%) 2 (22%)

166 (95%)

Preferred antimicrobials • Nitrofurantoin monohydrate/macrocrystals 100 mg BID x 5 days • TMP-SMX 160/800 mg BID x 3 days • Fosfomycin 3 g x 1 dose • Pivmecillinam 400 mg BID x 5 days Alternative antimicrobials • Fluoroquinolones (due to side-effect profile) • β -lactams (due to inferior efficacy and side-effect profile)

Yes 12 (86%) 161 (95%) No 2 (14%) 8 (4.7%) *Preferred Antimicrobials: Nitrofurantoin, TMP-SMX 1 Fisher's exact test

8 (4.6%)

1 Fisher's exact test

Table 2. Demographic Information and Clinical Characteristics

Antimicrobial Allergy n = 40

Discussion and Conclusions

No Allergy n = 143

Overall N = 183 1

p-value 0.004 2

Methods

Age Group

• Patients with an antimicrobial allergy were less likely to receive guideline recommended antimicrobial for the treatment of acute uncomplicated cystitis • No statistical difference existed in secondary outcome analyses, likely due to a small sample size for these subgroup analyses • Study limitations include use of retrospective electronic documentation for data, strict inclusion/exclusion criteria potentially limiting external validity of data, and the inability to capture outside patient factors that may have influenced prescribing other than the presence of antimicrobial allergy • Future implications include the development of a quality improvement project to assess the impact of an educational initiative on antimicrobial prescribing in this population

18-29 30-39 40-50 Black White Other

5 (12%) 17 (42%) 18 (45%) 16 (40%) 23 (57%) 1 (2.5%)

56 (39%) 35 (24%) 52 (36%) 70 (49%) 50 (35%) 23 (16%)

61 (33%) 52 (28%) 70 (38%) 86 (47%) 73 (40%) 24 (13%)

• Study approved by Spartanburg Regional Healthcare System (SRHS) Institutional Review Board (1711429-1)

Race

0.012 2

• Retrospective cohort study of female subjects ages 18 to 50 with uncomplicated cystitis at SRHS Center for Family Medicine outpatient between December 1, 2017, and December 31, 2021 • Data was acquired through an electronic medical record (EPIC) using International Classification of Diseases (ICD-10) coded data • The primary outcome of this study is receipt of guideline-recommended antimicrobial therapy • Secondary outcomes include: • Prevalence of antimicrobial allergies • Subgroup analyses of patients with an allergy to a preferred antimicrobial agent (TMP-SMX or nitrofurantoin) for 1) receipt of a guideline recommended antimicrobial agent or 2) receipt of a fluoroquinolone

Patient characteristics Diabetes mellitus

2 (5.0%) 10 (25%)

15 (10%) 26 (18%)

17 (9.3%) 36 (20%)

0.37 3 0.34 2

Current smoker Pathogen isolated Escherichia coli 1 n (%) 2 Pearson's Chi-squared test 3 Fisher's exact test

References

9 (22%)

45 (31%)

54 (30%)

0.27 2

1. Finn SD. Acute uncomplicated urinary tract infection in women. N Engl J Med. 2003;349:259-66. 2. Gupta K, Hooton TM, Naber KG, Wullt B, Colgan R, Miller LG, Moran GJ, Nicolle LE, Rax R, Schaeffer AJ, Soper DE. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the infectious disease society of America and the European society for microbiology and infectious disease. Clinical Infectious Diseases. 2011;52(5):e103-e120.

Table 3. Allergy Summary

Documented Antimicrobial Allergies (n=40) β -lactam 24 (60%) TMP-SMX 9 (22%) Nitrofurantoin 5 (12%) Fluoroquinolone 2 (5.0%)

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