THU0545 THE ASSOCIATION OF RHEUMATOID ARTHRITIS WITH HEALTH CARE COSTS FROM THE PAYERS PERSPECTIVE FROM 2001-2015
Authors: M. Tatangelo, G. Tomlinson, J. M. Paterson, N. Bansback, E. Keystone, C. Bombardier
Journal: Annals of the Rheumatic Diseases (2020)

Background: Costing studies require long-term follow-up data ideally within a homogenous payment structure without multiple potential insurers. We examined trends in associated costs of rheumatoid arthritis from the public payer’s perspective over time. Objectives: The purpose of this study was to measure the population RA associated direct and indirect health care costs using statistical attribution methods among a population with identical health care coverage. Methods: The study was matched longitudinal study of patients with algorithm defined RA residing in Ontario Canada with an RA diagnosis from 2001-2016 (n=104,933). Cases were matched 1:1 during the year of first diagnosis to 2 distinct control groups without RA. Control group 1 were matched on year of birth, and sex (underlying costs). Control group 2 were matched on year of birth, sex, and medical history. Medical history was measured using The John Hopkins Expanded Diagnostic Clusters, a tool that categorizes people with similar conditions based upon their use of healthcare services (physician visits, hospitalizations, emergency department visits, ambulatory care). After matching, healthcare costs were reported in 2015 Canadian Dollars (CAD) overall and by cost sub-category by exposure group and calendar year before versus after RA diagnosis. RA-associated costs were measured as the difference in costs among RA patients and their corresponding matched comparators. Results: At the year of diagnosis, RA cases were predominantly female (70%, n=72,873), mean year of birth 1950, (SD=17.7, Range=1910-2000), with mean year of diagnosis 2006, (SD=6.3, Range=2001-2016). RA patients experienced inceased indirect cost acquisition compared to the direct costs of RA alone. The health care costs of RA patients were identical to age/sex/medical history matched controls yet rising up until 2 years before RA diagnosis where they diverged from age/sex/disease matched controls $3,585/ptyr compared to $3,352/ptyr. The costs of RA patients were highest $8,468 CAD/ptyr ($888,572,644 total) in the year of diagnosis declining to a steady state by 2 years post diagnosis $7,867/ptyr with a slight increase in costs by 8 years post diagnosis $8,035/ptyr in (Figure 1). Differences age/sex matched controls were detectable throughout the study time period even up to 19-years pre-diagnosis. In the year of diagnosis, the direct costs of RA were $4046/ptyr (8468-4422), while the indirect costs of RA were $1254/ptyr ($4422-$3168) and the underlying age-sex specific costs were $3,168/ptyr. Our analysis suggest that both the direct and inflammatory costs of RA are growing over time compared to matched controls (Figure 1) by year 8 the direct joint-related costs of RA were 2528 (8035-5507) the indirect costs were 1,144 (5507-4363) and the age/sex underlying costs were 4,363. Figure 1. Annual Per-Patient Total Health Care Costs Over Time Grouped by Exposure Before and After Rheumatoid Arthritis Diagnosis Conclusion: The costs of RA have grown over time with medications representing a smaller than expected portion of total costs but a large increase in costs relative to matched controls. These results indicate that the direct costs of RA are decreasing over time compared to matched controls at 8 years post diagnosis and that over time, the indirect associated portion of costs remains almost constant, showing that over time the costs of indirectly related issues are becoming a larger proportion of total costs. Methodological advancements in costing attribution over time could contribute to understanding the patterns in health care resource usage among populations with chronic diseases. Disclosure of Interests: Mark Tatangelo: None declared, George Tomlinson: None declared, J Michael Paterson: None declared, Nick Bansback: None declared, Edward Keystone Grant/research support from: AbbVie; Amgen; Gilead Sciences, Inc; Lilly Pharmaceuticals; Merck; Pfizer Pharmaceuticals; PuraPharm; Sanofi, Consultant of: AbbVie; Amgen; AstraZeneca Pharma; Bristol-Myers Squibb Company; Celltrion; F. Hoffman-La Roche Ltd.; Genentech, Inc; Gilead Sciences, Inc.; Janssen, Inc; Lilly Pharmaceuticals; Merck; Myriad Autoimmune; Pfizer Pharmaceuticals, Sandoz, Sanofi-Genzyme, Samsung Bioepsis., Speakers bureau: AbbVie; Amgen; Bristol-Myers Squibb; Celltrion; F. Hoffman-La Roche Ltd, Janssen, Inc; Merck; Pfizer Pharmaceuticals; Sanofi-Genzyme; UCB, Claire Bombardier Grant/research support from: Dr Bombardier reports sources of funding for Ontario Best Practice Research Initiative Research grants from Abbvie, Janssen, Amgen, Medexus, Merck, Pfizer, and Novartis outside of the submitted work. Consulting Agreements: Abbvie, Covance, Janssen, Merck, Pfizer, Sanofi and Novartis outside of the submitted work. Advisory Board Membership: Hospira, Sandoz, Merck, Pfizer and Novartis outside of the submitted work.