Variability in the performing of spirometry and its consequences in the treatment of COPD in primary care

Background: Several studies have approached the use of spirometry in the treatment of chronic obstructive pulmonary disease (COPD) in Primary Care (PC), but few have analysed its impact on the treatment of the patient with COPD.

Objectives: To evaluate the use of spirometry in the diagnosis and follow-up of COPD patients in PC, and its impact on treatment. To analyse the variation in the performing of spirometry between PC centres.

Methodology: A multicentre, observational and cross-sectional study of COPD patients seen in PC in Catalonia (Spain) during 2004-2005. A multilevel logistic regression model was used to identify factors associated with having spirometry and to determine the variation between the different centres.

Results: Twenty-one centres which included 801 patients took part. Only 53.2% of them had a diagnostic spirometer available and the mean (standard deviation) FEV1(%) was 54.8% (18%). The registers of smoking habits, complementary tests and spirometry follow-up were more common among patients who had a diagnostic spirometry available compared to those who did not. No statistically significant differences were found as regards demographic, clinical, treatment and quality of life variables between patients with and without follow-up spirometry. Significant variation was observed in the percentage of diagnostic spirometries between different PC centres (variance=0.217; p<0.001).

Conclusion: Spirometry is underused in PC and performing it during follow-up is not associated to the different treatments received, or with a more complete approach to the disease. There is significant variation in the performing of spirometry among PC centres.