Background: The prevalence of asthma and chronic obstructive pulmonary disease (COPD) is high ( approximately 7.4-18%) in the general population, but less than half are diagnosed. Several studies have shown FEV(6) as a good surrogate marker for forced vital capacity (FVC) to detect airflow limitations.
Objectives: The aim of this study was to evaluate if it is possible to simplify and improve the diagnosis of so far undiagnosed asthma or COPD in the primary care setting by measuring FEV(6) with a new simple screening device (PiKo-6).
Methods: 507 patients were recruited from three general practices from May to June 2005. Patients with any known pulmonary disease were excluded by questionnaire. FEV(1), FEV(6) and FEV(1)/FEV(6) were determined using a PiKo-6 device. Patients with an FEV(1)/FEV(6) <80% (PiKo positive) were invited to a standardized pulmonary function test to confirm or rule out airflow limitation.
Results: 401 (79.1%) patients showed FEV(1)/FEV(6) > or =80% (PiKo negative), and 106 (20.9%) patients were PiKo positive. Of the 106 PiKo-positive patients, 74 patients (14.7% of total) agreed to further studies and 18 patients (3.6%) of them suffered from COPD [COPD 0: 5 (1.0%); COPD I: 9 (1.8%); COPD II: 4 (0.8%), and none with COPD III or IV] and 14 patients (2.8%) suffered from bronchial hyperresponsiveness or asthma. In 42 patients (8.3%), the pulmonary function test was normal.
Conclusions: Measurement of FEV(6) using a new simple screening device (PiKo-6) may improve the detection rate of undiagnosed airflow limitation in the primary care setting. However, patients should be carefully selected.