Multi-Health System Comparison of Outpatient Diagnostic Testing for Urinary Tract Infection

Abstract

Abstract Introduction/Objective Comparisons of diagnostic test utilization for outpatient encounters across multiple health systems are uncommon. Such comparisons are helpful to establish baseline diagnostic testing patterns across health systems. Methods/Case Report Using the Vizient Clinical Database, we compared the number of clinical laboratory tests (CPT codes 80000-89999) and imaging studies (CPT codes 70000-79999) per outpatient encounter for patients with urinary tract infection (UTI, N=97,714) or dysuria (N=125,388). We employed primary ICD-10 codes for UTI (N39.0) and dysuria (R30.0, R30.9, R35.0, R39.15) to define each patient group. We measured the aggregate Clinical Resource Intensity Weight (RIW) per outpatient visit to quantify diagnostic resource consumption for each encounter. The RIW is based on the US Centers for Medicare and Medicaid Services (CMS) Ambulatory Payment Classification (APC) weights. CMS assigns an APC weight to each diagnostic test based on the geometric mean cost of each particular test. We compared diagnostic testing at 20 academically affiliated health systems across the United States (2017- 2019) with >500 annual outpatient visits for UTI and dysuria. We also examined two relevant tests: urinalysis (CPT codes 8100, 81001, 81002, 81003, 81005, 81007, and 81015) and basic urine culture (CPT code 87086) testing patterns. Results (if a Case Study enter NA) The mean number of laboratory tests was 4.30 tests (range 3.04-5.89) and 3.01 (range 2.41-3.86) for UTI and dysuria patients, respectively. Average laboratory RIW and quantity were moderately correlated with a mean RIW of 0.50 and 0.38 for UTI and dysuria patients, respectively. The mean number of imaging studies for each group was 0.26 (range 0.08-0.46) and 0.05 (range 0.01-0.14), respectively. Average imaging RIW and quantity were more highly correlated with a mean RIW of 0.52 and 0.11 for UTI and dysuria patients, respectively. UTI encounters averaged 0.78 (range 0.38-1.28) urinalysis tests and 0.65 (range 0.39-0.86) urine cultures. Dysuria patient visits averaged 0.77 (range 0.45-1.17) urinalysis tests and 0.58 (range 0.13-0.76) urine cultures. Conclusion There are significant differences in diagnostic tests and resource utilization between large health systems for patients with UTI and dysuria. These differences persist with specific test comparisons for urinalysis and urine culture.