Pediatric Rheumatology Online Journal → June 2003 → Miscellaneous Topics→ Abstract #78

INITIAL VALIDATION OF THE WILLINGNESS TO PAY (WTP) TECHNIQUE FOR MEASURING HEALTH CARE PREFERENCES IN JUVENILE IDIOPATHIC ARTHRITIS (JIA)

H. I. Brunner, A. C. Barron, J. L. Taylor, P. G. Melson, B. T. Graham, D. J. Lovell

¹Rheumatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH

Background: WTP estimates are highly tangible and thus suitable for measuring health care preferences. The feasibility and usefulness of WTP in JIA has not been examined.
Objective: To assess the feasibility and construct validity of the WTP for measuring health preferences in JIA.
Method: Parents were asked to estimate the monthly US dollar amount they would be willing to pay to obtain for their child 1) Drug A that provides near complete relief of arthritis symptoms (WTP(A)) and 2) Drug B that eliminates gastrointestinal (GI) symptoms (WTP(B)). A closed-ended question approach (yes/no) was used with random assignment of the initial bids (Drug A: $50/$125/$200/$300; Drug B: $5/$25/$30/$40). Parents who agreed to pay the initial bid were then asked whether they would pay 200% and then 400% of this initial bid. Information was obtained regarding family income, health care expenses as well as on various JIA outcomes: number of involved joints; visual analog scales of pain, GI discomfort and overall well-being; Childhood Health Assessment Questionnaire (CHAQ); the Pediatric Quality of Life Inventory Rheumatology Module (PedsQL-R) and Generic Core Scale (PedsQL-G). Spearman correlations and regression analysis were done to examine the relationship between the WTP(A) or WTP(B) and other JIA outcomes.
Results: 54 families of children with JIA (mean age: 10 yrs) were interviewed. 54% of the patients had some GI discomfort and the mean/median number of involved joints was 4.3/2. WTP rating was refused by 5 families (9%). The mean/median of WTP(A) was $323/$200 and $54/$38 for WTP(B), respectively. After adjustment for the monthly family income, WTP (A) and WTP (B) were moderately corrrelated to pain, CHAQ, PedsQL-R and PedsQL-G (r= 0.35-0.47).
Conclusions: WTP appears to be a promising, easy to use method for assessing health care preferences in JIA. WTP is feasible and has construct validity in JIA. Further validation in a larger group of patients is warranted.