title: Psychometric properties of the Physical Activity Scale for the Elderly in Chinese patients with COPD.
abstract: BACKGROUND
  For patients with COPD, physical activity (PA) is recommended as the core component of pulmonary rehabilitation, but there is lack of a validated questionnaire for assessing the PA effectively.
  
  
  OBJECTIVE
  To evaluate the reliability and validity of the Chinese version of Physical Activity Scale for the Elderly (PASE-C) in patients with COPD.
  
  
  METHODS
  A cross-sectional study was conducted with 167 outpatients aged 60 years or older with COPD. Test-retest reliability and internal consistency were calculated by intraclass correlation coefficient (ICC) and Cronbach's coefficient α, respectively. Validity was evaluated by correlation with the International Physical Activity Questionnaire-Short (IPAQ-S), data of pedometer, Self-Efficacy for Managing Chronic Disease 6-Item Scale (SES6), Hospital Anxiety and Depression Scale (HADS), Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), grip strength, and disease characteristics.
  
  
  RESULTS
  The PASE-C had an excellent seven-day test-retest reliability (ICC=0.98) and an acceptable internal consistency (Cronbach's α=0.71). The content validity was supported by an item-content validity index, a scale-content validity index/universal agreement, and a scale-content validity index/average value of 0.70-1, 0.70, and 0.93, respectively. Concurrent validity was tested by correlation with IPAQ-S (r=0.651). Criterion validity was confirmed by correlation with the walking steps (r=0.611) and energy expenditure (r=0.493). For construct validity, PASE-C had correlations with SES6 (r=0.396), HADS for depression (r=-0.234), seven subscales of SF-36 (r=0.182-0.525), grip strength (r=0.341), and disease characteristics including the duration of COPD (r=-0.215), modified British Medical Research Council scale (r=-0.354), forced expiratory volume in one second as percentage of predicted (r=0.307), and Global Initiative for Chronic Obstructive Lung Disease grade (r=-0.264), with a good construct validity (allP<0.05).
  
  
  CONCLUSIONS
  The PASE-C has acceptable reliability and validity for patients aged 60 years or older with COPD, and it can be used as a valid tool to measure the PA of patients with COPD in the People's Republic of China.
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Tao
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Dong
authors.affiliation: Department of Respiratory Care, Tianjin First Center Hospital, Tianjin, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Respiratory Care, Tianjin First Center Hospital, Tianjin, People's Republic of China.
authors.forename: Ya-Shu
authors.initials: YS
authors.lastname: Zheng
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Xing-Yue
authors.initials: XY
authors.lastname: Tang
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Nursing, Tianjin Medical University.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D044466:Asian People / Q000523:psychology*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D015444:Exercise; D017079:Exercise Tolerance; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011594:Psychometrics; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013997:Time Factors; D016138:Walking
keywords: COPD; Physical Activity Scale for the Elderly; elderly; physical activity; reliability; validity