Psychometric Assessment of the Japanese Version of the Zurich Claudication Questionnaire (ZCQ): Reliability and Validity

• Published in: PloS one Vol. 11; no. 7; p. e0160183
• Main Authors: Hara, Nobuhiro, Matsudaira, Ko, Masuda, Kazuhiro, Tohnosu, Juichi, Takeshita, Katsushi, Kobayashi, Atsuki, Murakami, Motoaki, Kawamura, Naohiro, Yamakawa, Kiyohumi, Terayama, Sei, Ogihara, Satoshi, Shiono, Hiroo, Morii, Jiro, Hayakawa, Keiji, Kato, So, Nakamura, Kozo, Oka, Hiroyuki, Sawada, Takayuki, Inuzuka, Kyoko, Kikuchi, Norimasa
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.07.2016; Public Library of Science (PLoS)
• Subjects: Aged; Analysis; Back; Balances (scales); Biology and Life Sciences; Cardiovascular diseases; Correlation; Correlation coefficient; Correlation coefficients; Diabetic neuropathy; Disability; Female; Hospitals; Humans; Japan; Leg; Legs; Low back pain; Lumbar Vertebrae - physiopathology; Lumbar Vertebrae - surgery; Male; Medical research; Medicine and Health Sciences; Middle Aged; Pain; Patient Satisfaction; Patients; Psychodiagnostics; Psychometrics; Quality of life; Quantitative psychology; Questionnaires; Reliability analysis; Research and Analysis Methods; Social Sciences; Spinal stenosis; Spinal Stenosis - physiopathology; Spinal Stenosis - surgery; Stenosis; Surgery; Surveys and Questionnaires; Validity; United States; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0160183

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. 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. 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). 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.