TY - JOUR T1 - The epidemiological impasse JF - European Respiratory Journal JO - Eur Respir J SP - 480 LP - 480 DO - 10.1183/09031936.00043111 VL - 38 IS - 2 AU - F.A.A. Mohamed Hoesein AU - P. Zanen Y1 - 2011/08/01 UR - http://erj.ersjournals.com/content/38/2/480.1.abstract N2 - To the Editors:We read with interest the letter of Quanjer et al. [1] persuading the Global Initiative for Chronic Obstructive Lung Disease (GOLD) committee to abandon the fixed ratio of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.70 in favour of the lower limit of normal (LLN).We feel that, in the current debate, some basic epidemiological principles … ER -