Annual change in lung density measured as the 15th percentile point (abbreviated as Perc15 or PD15), FEV1 and gas transfer in placebo-treated patients in randomised controlled trials or studies on the natural course of AATD-associated emphysema

Author, year [Ref.]Patients nFollow-up monthsPerc15 (PD15) value g·L−1FEV1 mL·year−1DLCO mmol·min−1·kPa−1KCO mmol·min−1·kPa−1·L−1
Dirksen, 1999 [51]2836−2.57±0.41#−59.1±11.9#−0.16±.04#−0.0162±0.004#
Dirksen, 2009 [52]3525−2.241 (−2.90–  −1.577)−23 mL (−0.043– −0.004)−0.343 (−0.489– −0.196)−0.035 (−0.051– −0.020)
Stolk, 2012 [146]11014−1.81±0.5#−50±13#−0.23±0.05#NA
Stolk, 2015 [147]5196NA−66 ± 60.9+NA−0.0275±0.00259+
Chapman, 2015 [53]8724−2.19±0.23#−2.3±13.1%§−1.5±19.5%§NA
Green, 2016 [111]7624−3.2±0.5−44.67±8.71−0.37±0.04−0.01±0.01

FEV1: forced expiratory volume in 1s; AATD: α1-antitrypsin deficiency; DLCO: diffusing capacity of the lung for carbon monoxide; KCO: transfer coefficient of the lung for carbon monoxide i.e. DLCO/alveolar volume; NA: not available in the manuscript. #: mean±se; : (95% CI); +: mean±sd; §: annual decline in % predicted.