In centers that use lower limit of normal (LLN), the FEV1/VC LLN threshold should be used. The prevalence of COPD in Serbia is underestimated.3C5 High smoking prevalence, exposure to biomass fuels, and poor air quality all increase the risk of COPD in Serbia. side effects, and ensure efficient treatment. strong class=”kwd-title” Keywords: COPD, treatment, guidelines… Continue reading In centers that use lower limit of normal (LLN), the FEV1/VC LLN threshold should be used