The diagnostic accuracies of chronic obstructive pulmonary disease (COPD) in general practice: The results of the MAGIC (Manchester Airways Group Identifying COPD) study.

BACKGROUND: Although it is generally accepted that chronic obstructive pulmonary disease (COPD) is underdiagnosed, there is little objective information concerning the size of the problem in the UK.
METHOD: Patients from two general practices were offered spirometry if they were aged 30 or older, had reported ever smoking in one of four postal respiratory surveys (1993-2001), and/or reported four or more symptoms or risk factors in 2001 indicating likely obstructive airways disease.
RESULTS: Of 2646 subjects invited, 871 attended and 825 had adequate spirometry results for analysis. In all, 163 patients had spirometrically-confirmed COPD; 103 of these (63.2%) had no recorded COPD in their practice records, including 14 out of 31 (45.2%) whose spirometry results classified them as having severe or very severe COPD.
CONCLUSION: This study found a considerable under-recording of COPD in two general practices. This may be due to a combination of administrative and diagnostic problems (including the under-use of spirometers), and a reluctance of patients to present with their symptoms. These results have important implications in terms of unmet need and resource utilisation.