A comparison of two respiratory symptoms questionnaires.
D000328:Adult; D000368:Aged; D001991:Bronchitis / Q000175:diagnosis* / Q000453:epidemiology*; D004739:England; D004812:Epidemiologic Methods; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012907:Smoking; D013183:Sputum / Q000032:analysis