title: Estimation of minimal clinically important change of the Japanese version of EQ-5D in patients with chronic noncancer pain: a retrospective research using real-world data.
abstract: BACKGROUND
  Quality of life (QoL) is routinely assessed and evaluated in medical research. However, in Japan, there is a lack of solid cutoff criteria for evaluating QoL improvement in chronic noncancer pain management. The present study was conducted to identify the minimal clinically important change (MCIC) of the Japanese version of EuroQol-5D 3L(EQ-5D) utility score and numeric rating scale (NRS) with an emphasis on chronic noncancer pain.
  
  
  METHODS
  The data source for this post hoc research was the post-marketing surveillance (PMS) data for a tramadol/acetaminophen combination tablet, which was previously conducted in real-world settings. The parameters extracted from the PMS data were sociodemographic characteristics, NRS, EQ-5D, and dichotomous physician's global impression of treatment effectiveness (PGI). The optimal cutoff points of MCIC for EQ-5D utility and NRS scores were evaluated using receiver operating characteristics (ROC) analysis. An anchor-based approach using PGI was applied.
  
  
  RESULTS
  Data of 710 patients with chronic noncancer pain were extracted from the PMS database. The NRS score decreased by 2.7 (standard deviation, 2.3) points, whereas the EQ-5D score increased by 0.16 (0.20) points at 4 weeks from baseline. The changes from baseline in NRS and EQ-5D were significantly correlated (r = 0.53, p < 0.001). The estimated optimal cutoff points of MCIC for EQ-5D and NRS were 0.10 and -2.0 points, respectively. The area under the curve of ROC was > 0.80 in both analyses.
  
  
  CONCLUSIONS
  These results demonstrated novel cutoff criteria for the Japanese version of EQ-5D, focusing on patients with chronic noncancer pain. The obtained criteria were fairly consistent and can be confidently utilized as an evaluation tool in medical research on chronic noncancer pain in Japan, with additional functionality and usability for QoL assessment in pain management practice.
  
  
  BACKGROUND
  The data source of this post hoc research was a PMS study with the identifier number UMIN000015901 at umin.ac.jp, UMIN clinical trial registry (UMIN-CTR).
authors.affiliation: Medical Affairs Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. kyoshiz1@its.jnj.com.
authors.forename: Kazutake
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Medical Affairs Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. hkobaya1@its.jnj.com.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Japan Safety & Surveillance Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. mfujie@its.jnj.com.
authors.forename: Motoko
authors.initials: M
authors.lastname: Fujie
authors.affiliation: Japan Safety & Surveillance Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. yogawa2@its.jnj.com.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Ogawa
authors.affiliation: Biostatistics Department, Quantitative Science Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. tyajima1@its.jnj.com.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yajima
authors.affiliation: Medical Affairs Division, Janssen Pharmaceutical K.K., 3-5-2, Nishikanda, Chiyoda-ku, Tokyo, Japan. kojikawai2@gmail.com.|Sendai Pain Clinic Center, Medical Corporation Kanteikai, 99-1, Akai, Higashi Matsushima City, Sendai, Japan. kojikawai2@gmail.com.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D059350:Chronic Pain / Q000188:drug therapy* / Q000523:psychology*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010361:Patients / Q000523:psychology* / Q000706:statistics & numerical data*; D011788:Quality of Life / Q000523:psychology*; D012044:Regression Analysis; D012189:Retrospective Studies; D014147:Tramadol / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol