OBJECTIVES: To compare health care utilization (HRU) and costs between patients with and without atherosclerosis in the US veteran population.

METHODS: Patients with ≥1 medical claim for atherosclerosis (International Classification of Diseases, 9^th and 10^th Revision, Clinical Modification [ICD-9-CM; ICD-10-CM] diagnosis codes [ICD-9-CM code 440; ICD-10-CM code I70]) were identified from 01JAN2012 through 31DEC2016 using the Veterans Health Administration datasets. The first diagnosis date was designated as the index date. Each control patient (without atherosclerosis) was matched with an atherosclerosis patient of the same age, region, gender, and index year. A random index date was chosen for the control cohort to reduce selection bias. All patients were required to have continuous health plan enrollment for 12 months pre- and post-index date. One-to-one propensity score matching (PSM) was performed to compare follow-up HRU and costs between the cohorts, adjusting for demographic characteristics and the pre-index Charlson comorbidity index (CCI) score.

RESULTS: In each cohort, 65,933 patients were identified. The mean age was 72 years for controls and 71 years for cases. The mean CCI score was 3.0 for both cohorts. After applying 1:1 PSM, a total of 41,233 patients were matched from each cohort, and baseline characteristics were well-balanced. Atherosclerosis patients incurred higher HRU compared to controls, including inpatient (17.1% vs 3.3%), outpatient (99.6% vs 70.4%), and pharmacy (91.5% vs 70.9%) (all p<0.001) visits. Consistent with the trend of HRU, inpatient ($8,485 vs $1,014), outpatient ($6,156 vs $2,430), pharmacy ($998 vs $595) and total ($15,639 vs $4,040) (all p<0.001) costs were significantly higher among atherosclerosis patients compared to control patients.

CONCLUSIONS: Patients diagnosed with atherosclerosis incurred significantly higher HRU and costs compared to control patients in the US veteran population.