Does an easy device help doctors to diagnose COPD.

Rationale: FEV1/FEV6 ratio assessment in a GP’s office may be an acceptable and efficient approach to preselect candidates for full spirometry testing in primary care. Previous research revealed that a pre-BD FEV1/FEV6 < 0.73 for microspirometry resulted in a negative predictive value of 95.3%.

Objective: To evaluate the added value of a pre-bronchodilator FEV1/FEV6 determination with a microspirometer by the GP in the diagnostic process of COPD and attitude of GPs.

Study design: A cluster-randomised trial with an observation period of six months per participating general practice.

Study population: 22 practices with at least 10 patients each that visited the GP with respiratory complaints that could indicate COPD, are (ex-)smokers and 50 years or older, were not diagnosed with asthma or COPD and did not underwent an spirometric examination in the previous 5 years. GPs of a participating practice will be allocated to the same treatment arm.

Intervention: GPs in the intervention group will be trained in the use of a microspirometer and are asked to execute three pre-bronchodilator FEV1/FEV6 measures with a microspirometer for patients that fulfilled the study population criteria. Patients with a FEV1/FEV6 < 0.73 are recommended to be referred to full spirometry.

Main study parameters/endpoints: The main endpoint of the study is the difference in proportion of eligible patients that completed the diagnostic lung function process within 3 months after the initial GPs’ office visit between intervention and usual care group. Secondary outcome include: proportion of patients with an objectified airflow obstruction, GPs attitude towards COPD (diagnosis), a detailed process-evaluation, costs, and accuracy of referrals that were based on microspirometry.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness: If a FEV1/FEV6 measure without the administration of a bronchodilator is able to preselect patients with a chronic airway obstruction this could reduce the number of unnecessary full spirometric tests. Patients that visit an intervention practice could be asked to blow three times in a device for 6 seconds. Moreover, patients could be asked to undergo full spirometric examinations that do not differ from regular procedures when a COPD screening is carried out in a general practice. In other words, the burden and risk for the patients are minor and do not differ substantially from regular diagnostic COPD procedures. Only anonymous information of the patients will be collected. Patients are informed on study participation of the practice with information brochures in the waiting room. The research ethics committee of the Radboud University Nijmegen Medical Centre decided that this study doesn’t fall within the remit of the Medical Research Involving Human Subjects Act (WMO). Therefore, the study can be carried out (in the Netherlands) without an approval by an accredited research ethics committee.

Microspirometry result in a higher proportion of diagnostic spirometric assessment to objectify the existence or absence of a chronic airflow obstruction within 3 months after a patients at risk for COPD visited the GP compared to usual care.

Baseline assessment, 6 months follow-up.
Endpoint 9 months.

GPs will be instructed by an e-learning module on diagnosing chronic airway obstruction/COPD and the role of microspirometry therein, including a practical guide on how to use the microspirometer. Moreover, GPs receive microspirometers that could measure the FEV1/FEV6 ratio. During the 6 months observation time GPs are recommended to use the microspirometer for every patient that fulfilled the selection criteria. Moreover, the GPs are assisted in the use of the microspirometer by the study team at predetermined moments.