Validity of data collection tools was confirmed using content validity and their reliability was assessed by
Cronbach’s alpha internal consistency coefficient. In a sample of 15 subjects, Cronbach’s alpha score was
found to be 0.82 for self-care behavior questionnaire in COPD patients and 0.89 for self-efficacy evaluating tools in COPD patients which indicates the efficiency of these questionnaires. Data were analyzed by descriptive and analytic statistics using SPSS software (version 18; SPSS Inc., Chicago, IL, USA) and the cut-off point for statistical significance was set at P < 0.05.