Examination of spirometry techniques on instruction by medical technologists for screening purposes

BACKGROUND: The burden of chronic obstructive pulmonary disease (COPD) remains very high. Current consensus guidelines emphasize the importance of the early detection of COPD, but its underdiagnosis is common in general practice. Spirometry is the "gold standard" in the diagnosis of COPD. However, it remains underused in general practice because the application of spirometry is viewed as difficult to obtain accurate results. AIMS: To clarify the accuracy of spirometry techniques for screening purposes. METHOD: Subjects (n = 142) were told about the spirometry procedure using pre-determined descriptions, followed by the first spirometry test. Special medical technologists gave instructions on the detailed spirometry procedure on reference to the first test of results, and the second spirometry test was performed. The second spirometric indices, SVC, FVC, FEV1, FEV1%, and PEF, were compared with the first ones. RESULTS: The instruction by special medical technologists significantly improved all spirometric indices except for FEV1%. For a diagnosis of restrictive disorder (VC<80%), the impact of intervention by the special medical technologists was highly significant (p<0.001). In contrast, for the diagnosis of obstructive disorder (FEV1%<70%), the impact was small. CONCLUSION: To detect obstructive disorder, the high-level accuracy of special spirometry techniques is not always necessary.