Predicting inconsistency in airflow obstruction diagnosis by a logistic regression model.

LLN = lower limit of normal, 5th percentile of the ratio. FET = forced expiratory time; Model was also adjusted by age, gender, asthma, current smoking at second evaluation, a physician diagnosis of asthma. PostBD = post bronchodilator. The closer the ratio and the FEV1 to the diagnostic threshold, the higher the risk of inconsistency on repeated testing. Predicting inconsistency in airflow obstruction diagnosis by a logistic regression model.