Feasibility of spirometry in primary care to screen for COPD: a pilot study

COPD is a frequent but underdiagnosed disease whose diagnosis relies on the spirometric demonstration of bronchial obstruction. Spirometry use by general practitioners could represent the first line in COPD diagnosis.

Because duration of spirometry is retarding its development in primary care, we decided to measure the time it requires in the primary-care context in France.

Ten volunteer general practitioners were trained during two 3-hour theoretical and practical continuing education sessions. Then, from October 2013 to May 2014, they included patients without any known respiratory disease but at risk of developing COPD (age: ≥40 years, smoker: ≥20 pack-years). The duration of spirometry and its quality were evaluated according to the following acceptability criteria: 1) expiration ≥6 seconds or reaching a plateau; 2) good start with an early peak flow, curve peaked on top and not flat; 3) no artifacts; and 4) reproducibility criteria, ie, forced expiratory volume in 1 second and forced vital capacity differences between the two best spirometry curves ≤0.15 L. Quality of the spirograms was defined as optimal when all the criteria were met and acceptable when all the criteria were satisfied except the reproducibility criterion, otherwise, it was unacceptable.

For the 152 patients included, the 142 assessable spirometries lasted for 15.2±5.9 minutes. Acceptability criteria 1-3, respectively, were satisfied for 90.1%, 89.4%, and 91.5% of patients and reproducibility criterion 4 for 56.3%. Quality was considered optimal for 58.5% of the curves and acceptable for 30.2%.

The duration of spirometry renders it poorly compatible with the current primary-care practice in France other than for dedicated consultations. Moreover, the quality of spirometry needs to be improved.