Burden of Medically Attended Diarrhea and Outpatient Clostridioides difficile Infection Among Persons in 2 Large Integrated Healthcare Settings, 2016-2021

Sara Y Tartof; Mark A Schmidt; Richard Contreras; Frederick J Angulo; Ana Florea; Joanna L Barreras; Judy Donald; Joann Zamparo; Deborah Ling Grant; Elizabeth Shuster; Elisa Gonzalez; Jennifer L Kuntz

doi:10.1093/ofid/ofad680

Burden of Medically Attended Diarrhea and Outpatient Clostridioides difficile Infection Among Persons in 2 Large Integrated Healthcare Settings, 2016-2021

Open Forum Infect Dis. 2024 Jan 11;11(1):ofad680. doi: 10.1093/ofid/ofad680. eCollection 2024 Jan.

Authors

Affiliations

¹ Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.
² Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California, USA.
³ Science Programs Department, Kaiser Permanente Northwest Center for Health Research, Portland, Oregon, USA.
⁴ Vaccines, Antivirals, and Evidence Generation, Pfizer Inc, NewYork, New York, USA.

Abstract

Background: Identification of Clostridioides difficile infection (CDI) in the community setting is increasing. We describe testing for CDI among patients with medically attended diarrhea (MAD) in the outpatient setting, and the incidence of outpatient CDI.

Methods: This was a retrospective cohort study among members ≥18 years of age from Kaiser Permanente Southern California and Kaiser Permanente Northwest from 1 January 2016 through 31 December 2021. MAD was identified by outpatient diarrheal International Classification of Diseases, Tenth Revision diagnosis codes, and CDI through positive laboratory results. Outpatient CDI was defined by no hospitalization ≤7 days after specimen collection. Incidence rates (IRs) of outpatient CDI were stratified by select demographic and clinical variables. Outpatient CDI burden 12 months following index date was measured by CDI-associated healthcare visits, and CDI testing and treatment.

Results: We identified 777 533 MAD episodes; 12.1% (93 964/777 533) were tested for CDI. Of those tested, 10.8% (10 110/93 964) were positive. Outpatient CDI IR was 51.0 (95% confidence interval [CI], 49.8-52.2) per 100 000 person-years, decreasing from 58.2 (95% CI, 55.7-60.7) in 2016 to 45.7 (95% CI, 43.7-47.8) in 2021. Approximately 44% (n = 4200) received an antibiotic 30 days prior to index date and 84.1% (n = 8006) CDIs were "community-associated" (no hospitalizations 12 weeks prior to index date). Of outpatient CDIs, 6.7% (n = 526) had a CDI-associated hospitalization ≤12 months.

Conclusions: There was a high incidence of outpatient CDI despite infrequent CDI testing among patients with MAD. The majority of those with outpatient CDI had no recent antibiotic use and no recent hospitalization. Further studies are needed to understand the source and management of medically attended outpatient CDI.

Keywords: Clostridioides difficile; Kaiser Permanente; diarrhea; incidence; real-world.