PRM28 - Comparison of Methods to Estimate Disease-Related Cost in the Truven Marketscan Adminstrative Claims Database

Abstract

Compare four methods of calculating disease-related cost. This study utilized the Truven Marketscan® claims database and two disease cohorts, Rheumatoid Arthritis (RA) and Ulcerative Colitis (UC). Patients were age 18+, had two diagnoses for either RA or UC, no other autoimmune conditions and were continuously enrolled in 2015. Disease cohorts were matched to controls using age, gender, region and insurance type. In cost methods 1, 3, and 4, disease-related inpatient costs were attributed using the primary diagnosis field. In addition, method 1 included outpatient cost if the disease was on the claim and pharmacy cost using a pre-determined drug list. Method 2 included outpatient/pharmacy cost for procedures/medications occurring at increased frequency in the disease cohorts versus controls (1.5x and 3.5x were both tested). Method 3 used the difference in total cost between disease cohorts and matched controls. Method 4 (RA only) served as our internal standard method and utilized a separate stand-alone clinician review of codes received by the RA cohort. Outpatient/pharmacy claims flagged as RA-related were included in the Method 4 analysis. 24,373 RA patients and 9,665 UC patients were included. Average total cost was $28,750 per RA patient and $20,480 per UC patient. RA-related cost as a percent of total cost: method 1, 48%; method 2 (1.5x), 56%; method 2 (3.5x), 44%; method 3, 73%; method 4, 44%. UC-related cost as a percent of total cost: method 1, 50%; method 2 (1.5x), 50%; method 2 (3.5x), 42%; method 3, 70%. Percent disease-related cost attributed to each cost component (emergency room, inpatient, outpatient, pharmacy) tracked similarly comparing RA to UC within each method 1-3. In RA, our internal standard method 4 was closest in disease-related cost and cost component attribution to method 2 (3.5x). Method 2 (3.5x) is our proposed method for calculating disease-related cost.