title: Psychometric Assessment of the Japanese Version of the Zurich Claudication Questionnaire (ZCQ): Reliability and Validity.
abstract: OBJECTIVE
  The Zurich Claudication Questionnaire (ZCQ) is a self-administered measure to evaluate symptom severity, physical function, and surgery satisfaction in lumbar spinal stenosis (LSS). The purpose of this study is to assess the psychometric properties of the Japanese ZCQ in LSS patients.
  
  
  METHODS
  LSS patients who are scheduled to undergo surgery were recruited from 12 facilities. Responses to several questionnaires, including the Japanese ZCQ; the visual analogue scale (VAS) to evaluate the degree of pain in the buttocks/legs, numbness in the buttocks/legs, and low back pain; the Oswestry Disability Index (ODI); and the SF-36v2, were collected before surgery and again 3 months after surgery (the post-surgery ZCQ was administered twice for test-retest reliability). For reliability, test-retest reliability was evaluated using the intra-class coefficient (ICC) and internal consistency was evaluated using Cronbach's alpha coefficient. Concurrent validity was assessed using Spearman's correlation coefficients between the Japanese ZCQ and other questionnaires. Effect size (ES) and standard response mean were calculated for responsiveness. All analyses were performed individually for the Japanese ZCQ symptom, function, and satisfaction domains.
  
  
  RESULTS
  Data from 180 LSS patients were used in this analysis. The ICCs were 0.81, 0.89, and 0.88 and Cronbach's alpha coefficients were 0.78, 0.84, and 0.92 for the Japanese ZCQ symptom, function, and satisfaction domains, respectively. Regarding the concurrent validity, strong correlations (±0.5) were demonstrated between the Japanese ZCQ domains and the VAS leg pain, ODI, and SF-36v2 physical functioning or bodily pain, whereas correlations were approximately 0.3 in scales measuring other symptoms that are less related to symptom, function, or satisfaction domains. ESs showed high values for the ZCQ symptom and function domains (-1.73 for both).
  
  
  CONCLUSIONS
  These psychometric assessments demonstrate that the Japanese ZCQ is a psychometrically reliable and valid measure in LSS. The Japanese ZCQ can evaluate both multi-dimensional aspects and the level of surgery satisfaction.
authors.affiliation: Department of Orthopaedic Surgery, Musashino Red Cross Hospital, Musashino, Tokyo, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hara
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Matsudaira
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Metropolitan Tama Medical Center, Fuchu, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Department of Orthopaedic Surgery, Kanto Rosai Hospital, Kawasaki, Kanagawa, Japan.
authors.forename: Juichi
authors.initials: J
authors.lastname: Tohnosu
authors.affiliation: Department of Orthopaedic Surgery, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takeshita
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Metropolitan Bokutoh Hospital, Sumida-ku, Tokyo, Japan.
authors.forename: Atsuki
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopaedic Surgery, Toranomon Hospital, Minato-ku, Tokyo, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Shibuya-ku, Tokyo, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kawamura
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Metropolitan Komagome Hospital, Bunkyo-ku, Tokyo, Japan.
authors.forename: Kiyohumi
authors.initials: K
authors.lastname: Yamakawa
authors.affiliation: Department of Orthopaedic Surgery, Sangubashi Spine Surgery Hospital, Shibuya-ku, Tokyo, Japan.
authors.forename: Sei
authors.initials: S
authors.lastname: Terayama
authors.affiliation: Department of Orthopaedic Surgery, Sagamihara National Hospital, Sagamihara, Kanagawa, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ogihara
authors.affiliation: Department of Orthopaedic Surgery, Toranomon Hospital, Minato-ku, Tokyo, Japan.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Shiono
authors.affiliation: Department of Orthopaedic Surgery, Sanraku Hospital, Chiyoda-ku, Tokyo, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Morii
authors.affiliation: Department of Orthopaedic Surgery, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Hayakawa
authors.affiliation: Department of Orthopaedic Surgery, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: So
authors.initials: S
authors.lastname: Kato
authors.affiliation: National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oka
authors.affiliation: Clinical Study Support, Inc., Nagoya, Aichi, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sawada
authors.affiliation: Clinical Study Support, Inc., Nagoya, Aichi, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Inuzuka
authors.affiliation: Clinical Study Support, Inc., Nagoya, Aichi, Japan.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Kikuchi
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007564:Japan; D008159:Lumbar Vertebrae / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011594:Psychometrics; D013130:Spinal Stenosis / Q000503:physiopathology* / Q000601:surgery; D011795:Surveys and Questionnaires