title: Asymptomatic obstructive airway defect--an analysis of causal factors. A study involving 425 Nebraskans.
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009329:Nebraska; D009790:Occupations