Efficacy of two sputum collection techniques in patients with air flow obstruction

OBJECTIVE: To compare the efficacy of two sputum collection techniques in p atients with chronic obstructive pulmonary disease (COPD) in order to diagn ose dysplasia or neoplasia. STUDY DESIGN: This was a crossover study design comparing induced sputum wi th sputum collected at home. One hundred seven patients with COPD were enro lled. Fifty-sh were randomized to collect induced sputum first followed by sputum collection at home. Fifty-one randomly assigned patients collected t he sputum in reverse order. RESULTS: The second sputum collection technique for both random assignments gave the greatest yield of adequate sputum. There was no significant diffe rence in efficacy between the collection of the two sputum collection techn iques in the presence of the learning (period) effect. CONCLUSION: Sputum collection is equally efficacious by the induced method and the home collection method. A learning effect was responsibile for the increased yield of sputum abnormalities in the second collection session. S putum collection at home may facilitate the amount of dysplasic and neoplas tic bronchial epithelial changes in heavy smokers with COPD.