title: Profiles of EQ-5D utility scores in the daily practice of Japanese patients with rheumatoid arthritis; Analysis of the IORRA database.
abstract: OBJECTIVE
  Along with the advances of newly developed medical therapies in rheumatoid arthritis (RA), the number of pharmacoeconomical issues has been paid attention rapidly. For cost-utility analysis and determination of quality-adjusted life years, measurement of the EuroQol 5-dimensional descriptive system (EQ-5D) is essential, and has been used in several clinical studies. However, EQ-5D utility measure in Japanese patients with RA, especially in daily practice has not been fully documented. We analyzed the distribution of EQ5D utility scores and investigated the relationship between other clinical measures based on our Institute of Rheumatology, Rheumatoid Arthritis (IORRA) database.
  
  
  METHODS
  Among 5,284 outpatients who participated in the IORRA cohort study on October 2007, data from 5,043 patients who completed the EQ-5D questionnaire were cross-sectionally analyzed. EQ-5D scores in each subgroup for baseline feature such as gender, age, disease activity score 28 (DAS28), and Japanese version of health assessment questionnaire (J-HAQ) were evaluated. For the evaluation of variables that influenced EQ-5D score, the contribution of each variable was evaluated by ANOVA.
  
  
  RESULTS
  Average EQ-5D score was 0.76 in 5,284 patients (84% females, average age: 59.0 years, average disease duration: 12.4 years) whose average DAS28 was 3.3 and average J-HAQ was 0.74. EQ-5D scores were highly correlated with J-HAQ and DAS28, and were significantly lower in females and rheumatoid factor-positive patients. Older age, longer disease duration, higher DAS28, and higher J-HAQ were also significantly associated with lower EQ-5D scores. In multivariate analysis, the factor that most strongly influenced EQ-5D was J-HAQ (57.6%), followed by pain visual analog score (VAS; 12.5%).
  
  
  CONCLUSIONS
  This study clearly demonstrated the distribution of EQ-5D score in the daily practice of RA patients, and provides important information for the pharmacoeconomical studies in rheumatology.
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hoshi
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: b Department of Drug Policy and Management , Graduate School of Pharmaceutical Sciences, The University of Tokyo , Bunkyo-ku, Tokyo , Japan.
authors.forename: Ataru
authors.initials: A
authors.lastname: Igarashi
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Inoue
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Sugimoto
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Kumi
authors.initials: K
authors.lastname: Shidara
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Sato
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Seto
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Nakajima
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Momohara
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Taniguchi
authors.affiliation: b Department of Drug Policy and Management , Graduate School of Pharmaceutical Sciences, The University of Tokyo , Bunkyo-ku, Tokyo , Japan.
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Tsutani
authors.affiliation: a Institute of Rheumatology, Tokyo Women's Medical University , Shinjuku-ku, Tokyo , Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamanaka
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D011795:Surveys and Questionnaires
keywords: EQ-5D; Health assessment questionnaire; Health-related quality of life; Rheumatoid arthritis; Utility index