Bronchodilator reversibility testing: laboratory practices in Australia and New Zealand.

OBJECTIVES To determine the variation in the methods used to assess and interpret the reversibility of airflow limitation in lung-function laboratories throughout Australia and New Zealand. DESIGN A postal survey performed in 2000, requesting details of methods used to assess and interpret bronchodilator reversibility. SETTING AND PARTICIPANTS 60 lung-function laboratories identified from the Australian and New Zealand Society of Respiratory Science mailing list. MAIN OUTCOME MEASURES Bronchodilator agent, dose, mode of administration, time to repeat spirometry and definition of a significant response. RESULTS 37 laboratories responded (response rate, 64%). Thirty-three laboratories used salbutamol as their routine bronchodilator agent. Twenty-four laboratories used a metered-dose inhaler (MDI) with (21) or without (3) a spacer device as the preferred mode of bronchodilator administration. There was wide variation in the bronchodilator dose administered (median, 400 micro g; range, 200-800 micro g salbutamol for MDIs) and the time to repeat spirometry following bronchodilator administration (median, 10 min; range, 4-20 min). Ten laboratories used criteria consistent with either the National Asthma Council or Thoracic Society of Australia and New Zealand COPDX guidelines to define a significant bronchodilator response, and two used American Thoracic Society criteria. The remaining 25 respondents listed a variety of other criteria. CONCLUSION The methods used to assess and interpret acute bronchodilator reversibility in lung-function laboratories in Australia and New Zealand vary considerably. This may have a significant effect on the diagnosis and management of patients. Laboratories should report the method used to assess bronchodilator response.