title: Reliability and validity of the Chinese version of the Short Musculoskeletal Function Assessment questionnaire in patients with skeletal muscle injury of the upper or lower extremities.
abstract: BACKGROUND
  The Short Musculoskeletal Function Assessment (SMFA) questionnaire is one of the most commonly used scales to evaluate functional status and quality of life (QOL) of patients with a broad range of musculoskeletal disorders. However, a Chinese version of the SMFA questionnaire for the psychometric properties of skeletal muscle injury patients in China is still lacking. The current study translated the SMFA into Chinese and assessed its reliability and validity among Chinese patients with skeletal muscle injury of the upper or lower extremities.
  
  
  METHODS
  The original SMFA was translated from English into Chinese and culturally adapted according to cross-cultural adaptation guidelines. A multicenter cross-sectional study was conducted, comprising 339 skeletal muscle injury patients (aged 20-75 years) from 4 hospitals. The SMFA, the health survey short form (SF-36) along with a region-specific questionnaire (including the disabilities of the arm, shoulder, and hand questionnaire (DASH), the hip disability and osteoarthritis outcome score (HOOS), the knee injury and osteoarthritis outcome score (KOOS), and the foot function index (FFI)) were completed according to the region of injury. Reliability was estimated from the internal consistency using Cronbach's α and validity was assessed via convergent validity, known-groups comparison, and construct validity.
  
  
  RESULTS
  Cronbach's α coefficient was over 0.75 for two subscales and four categories of the SMFA, suggesting that the internal consistency reliability of the SMFA was satisfactory. Known-groups comparison showed that the dysfunction index and the bother index of the SMFA discriminated well between patients who differed in age, gender, injury location, and operation status rather than in subgroups based on the body mass index (BMI). The convergent validity of the SMFA was good, as moderate to excellent correlations were found between the subscales of the SMFA and the four subscales of SF-36 (physical function, role-physical, bodily pain, and social functioning) and the region-specific questionnaires. The construct validity was proved by the presence of a six-factor structure that accounted for 66.85 % of the variance.
  
  
  CONCLUSIONS
  The Chinese version of the SMFA questionnaire is a reliable and valid instrument to measure patient-reported impact of musculoskeletal injuries in the upper or lower extremities.
authors.affiliation: Department of Orthopedic Trauma, Nan Fang Hospital, Southern Medical University, Guangzhou, 510515, China. yinggreat@126.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Clinical Epidemiology, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. hezehui106@163.com.
authors.forename: Zehui
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Acupuncture, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. langlangyun@126.com.
authors.forename: Lifang
authors.initials: L
authors.lastname: Lei
authors.affiliation: Department of Orthopedic, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. lindingkun@126.com.
authors.forename: Dingkun
authors.initials: D
authors.lastname: Lin
authors.affiliation: Department of Nursing, Nan Fang Hospital, Southern Medical University, Guangzhou, 510515, China. yajieli001@sina.com.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Orthopedic Trauma, Nan Fang Hospital, Southern Medical University, Guangzhou, 510515, China. wgnfyy@126.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Humanistic Nursing, College of Nursing, Southern Medical University, Guangzhou, 510515, China. 798612447@qq.com.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhai
authors.affiliation: Library, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. xujl1015@163.com.
authors.forename: Jingli
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Nursing, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. hlbzhang@sina.com.
authors.forename: Guangqing
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Nursing, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, 510120, China. lmzmay@163.com.
authors.forename: Meizhen
authors.initials: M
authors.lastname: Lin
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D001134:Arm Injuries / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology / Q000523:psychology; D044466:Asian People / Q000523:psychology; D002681:China; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D003466:Cultural Characteristics; D004185:Disability Evaluation; D004644:Emotions; D005240:Feasibility Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007869:Leg Injuries / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000293:injuries* / Q000503:physiopathology; D009140:Musculoskeletal Diseases / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology / Q000523:psychology; D011237:Predictive Value of Tests; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014175:Translating; D055815:Young Adult