Applying medical expenditure data to disease severity scores
By Barbara Schwedel
Washington, DC—Mapping disease severity into a panel of economic data can help to predict the marginal economic effects of increasing severity of rheumatoid arthritis (RA), according to a first economic analysis of its type presented at a poster session during the 2012 International Society for Pharmacoeconomics and Outcomes Research annual meeting.
Using information from the Consortium of Rheumatology Researchers of North America (CORRONA) Registry, a patient registry that routinely collects clinical outcomes data from rheumatology practices across the United States, Michael Ingham, MSc, Health Economics & Outcomes Research Rheumatology Lead, at Janssen Scientific Affairs, LLC, in Horsham, PA, and colleagues compared data from CORRONA with cost data from a large cohort of patients with RA in the Medical Expenditure Panel Survey (MEPS).
Data were collected on 19,011 patients with RA from the CORRONA Registry and were compared with expenditure data from MEPS. A mapping algorithm was developed by applying the Clinical Disease Activity Index (CDAI) and modified Health Assessment Questionnaire (HAQ) severity scores in the CORRONA data set on a list of clinical factors relevant to patients with RA. Total healthcare costs for predetermined RA disease severity were then estimated based on data in MEPS.
Results showed that the annual costs of prescription medications represented from 10% to 30% of total healthcare expenditures for patients with RA.
Based on CDAI scores for patients with low RA activity, the incremental increase in total healthcare cost for patients with moderate disease activity was $3051 (95% confidence interval [CI], $1274-$4828) and $6221 (95% CI, $2110-$10,332) for patients with high disease activity.
Based on modified HAQ scores for patients with low RA activity, the incremental increases in total healthcare costs was $4149 (95% CI, $1194-$7104) for patients with moderate disease activity and $6102 (95% CI, $1870-$10,335) for those with high disease activity.
The researchers noted combining RA disease severity data and economic parameters can help to predict the economic effects of increases in disease severity. The results of this particular analysis indicate that patients with RA who can reach and maintain lower disease activity are likely to save substantial costs to the US healthcare system.