IMPACT OF ADMISSION URINE CULTURE ON ANTIBIOTIC USE AND HOSPTIAL LENGTH OF STAY

Molly Horstman, MD*1,2;Andrew Spiegelman, PhD3;Dr. Aanand Naik, MD1,2 and Barbara Trautner, MD, PhD1,2, (1)Baylor College of Medicine, Houston, TX, (2)Michael E. DeBakey VA Medical Center, Houston, TX, (3)The Advisory Board Company, Washington, DC

Meeting: Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev.

Abstract number: 81

Categories: Outcomes Research, Research Abstracts

Keywords: ,

Background: Overuse of urine testing may result in downstream events that impact antibiotic use and hospital length of stay (LOS). The aims of this study were to examine the impact of inpatient urine culture testing on inpatient antibiotic use and hospital length of stay using a national administrative dataset.

Methods: We performed a retrospective cohort study using a national dataset of adult hospitalizations from The Advisory Board Company from 2009 to 2014. We excluded hospitalizations that were pregnancy-related, had a urologic procedure, or had LOS greater than 30 days. The exposure was a urine culture on day 1 of hospitalization. Hospitalizations were matched with coarsened exact matching by facility, patient age, gender, Medicare Severity-Diagnosis Related Group (MS-DRG), DRG severity level, DRG mortality level, Elixhauser comorbidity score, and ICD-9 codes for infection on admission. A multi-level linear Poisson model and a multi-level linear regression model were used to determine the impact of urine culture on inpatient antibiotic use and LOS.

Results: Matching produced a cohort of 88,481 (n=41,070 with a urine culture on day 1, n=47,411 without a urine culture). A urine culture on day 1 of admission was associated with an increase in days of inpatient antibiotic use (incidence rate ratio 1.26; p-value <0.001). The impact of urine culture testing on antibiotic days was greatest for diagnoses where antibiotic use was uncommon (Table 1). The difference in antibiotic use between admissions with and without a urine culture on day 1 resulted in an additional 36,607 days of inpatient antibiotic use. Urine culture on day 1 of the admission resulted in a 2.1% (SE 0.7%) increase in LOS. The predicted difference in bed days of care between hospital admissions with and without a urine culture on the first day of admission resulted in 6,071 excess bed days of care overall. The impact of urine culture testing varied by MS-DRG. For example, urine culture testing on day 1 of the hospitalization resulted in a 4.5% increase in LOS (875 excess days) for patients admitted for major joint replacement of the lower extremity and 1,006 excess days of antibiotic use.  

Conclusions:  Collecting a urine specimen for culture is a simple procedure that has major downstream impacts.  Overall, patients with a urine culture sent on the first day of the hospital admission receive more days of antibiotics and have a longer hospital stay than patients who do not receive a urine culture. These findings varied by diagnosis group. Targeted interventions for specific diagnoses may achieve the best balance between reducing the potential harm associated with low-yield urine cultures and supporting clinician autonomy to order a culture in the appropriate clinical setting.

To cite this abstract:

Horstman, M; Spiegelman, A; Naik, A; Trautner, B . IMPACT OF ADMISSION URINE CULTURE ON ANTIBIOTIC USE AND HOSPTIAL LENGTH OF STAY. Abstract published at Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev. Abstract 81. Journal of Hospital Medicine. 2017; 12 (suppl 2). https://www.shmabstracts.com/abstract/impact-of-admission-urine-culture-on-antibiotic-use-and-hosptial-length-of-stay/. Accessed July 21, 2019.

« Back to Hospital Medicine 2017, May 1-4, 2017; Las Vegas, Nev.