A household survey of chronic obstructive pulmonary disease in Ottawa: methodological problems and results of pilot survey.
D000397:Air Pollution; D001991:Bronchitis; D002170:Canada; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D011639:Public Opinion; D011656:Pulmonary Emphysema; D012907:Smoking