The samples were patients who recently diagnosed of
COPD from 5 local hospitals. The samples size was
calculated to arrive at a minimum sample size of 304 cases.
The simple random sampling technique was used for
selecting the subjects after met the list of COPD cases from
hospitals. After providing the information by verbal to the
subjects about the objective and process of the study, then the
informed consent had been obtained before interview.
Inclusion criteria: a) COPD subjects had diagnosed for
COPD and visited at the COPD clinics, Chiang Rai
Province, b) with the complete medical records. Exclusion
Criteria: a) COPD cases who could not speak Thai, b) who
refused to participate.