Using a central database, analysis was carried out of all routine care spirometry tests (either a prebronchodilator test alone or a full reversibility test consisting of a prebronchodilator and a postbronchodilator test) that had been submitted by GPs from March 2003 to August 2005. Each of the 15 general practices involved owns a PC-based spirometer and software (SpiroPerfect™, Welch Allyn, Delft, the Netherlands). The hospital's pulmonary laboratory service has direct access to the tests submitted by GPs. Spirometry training and support has been offered to GPs (with a focus on test interpretation), practice nurses, and practice assistants (with a focus on performing tests) once or twice a year since the late 1990s.
How this fits in
Spirometry is an indispensable tool for primary care doctors and nurses to diagnose and monitor chronic airways disease. Good-quality spirometry requires comprehensive training of staff, reliable equipment, and well-standardised measurement procedures, which may be difficult to achieve in a general practice. In this study, the quality of routine spirometry tests was better than in previous reports from primary care research settings, but there is still substantial room for improvement. Sufficient duration of forced expiratory time is the quality marker with the highest rate of inadequacy. Primary care professionals should be aware of patient characteristics that may diminish the quality of their spirometry tests.
After online submission of results to the central database, the quality of spirometry tests is first judged by a pulmonary function technician. Based on the 1994 American Thoracic Society spirometry guideline,6 several spirometry quality markers were derived for every test submitted by the general practices. (It was decided not to use the more recent 2005 guideline10 because it had not yet been published at the time when the spirometry tests were performed.) Box 1 shows the test quality markers as extracted from the 1994 American Thoracic Society spirometry guideline, and for each marker whether or not it could be included in the study analysis of general practice spirometry test quality. Figure 1 shows examples of unacceptable blows for markers that can be judged from the flow–volume curve. After the pulmonary function technician's quality assessment, each test is diagnostically assessed by one of the hospital's chest physicians, who records the presence and/or severity of airflow obstruction, reversibility after bronchodilation, and a possible restrictive pattern. The combined results of the quality assessment and the diagnostic assessment of each test are reported back to the general practice.
