The sensitivity and specificity of spirometry as a screening method in COPD

Abstract

The data on COPD spread in various regions are extremely inconsistent. One of", the most accessible methods to define the COPD prevalence is screening. Spirometry is a gold standard for COPD detection. The purpose of the present research was to study sensitivity and specificity of spirometry in diagnosing COPD. We examined 3 129 persons aged 17 to 80 yrs. (1 867 males and 1 262 females), pensioners and workers of various enterprises at the Kemerovo city. A great number of persons with reduced respiratory function parameters were found during the screening. After more detailed examination the diagnosis of COPD was verified in 5.4 % of the males and 1.1 % of the females. The disease was detected more often in drivers, railway workers and healthcare workers. According to the screening results the most sensitive diagnostic criterion was FEV₁ < 80 % and the most specific parameter was FEV₁ / FVC < 70 %. Being highly specific PEF < 80 % had low sensitivity. The increase in PEF higher than 90 °%o enhanced its sensitivity up to 88.6 % and its drop less than 70 % augmented its specificity up to 95.5 %o. The results allow to recommend the PEF < 70 % parameter as a diagnostic criterion of COPD in everyday outpatient work and PEF < 90 % as an indication for more detailed examination.