Table 3.

Distribution-based estimates for key EORTC domain scores (N = 681)

EORTC domain	Test–retest reliabilitya	One-half standard deviationb	Standard error of measurement
EORTC QLQ-C30 Physical Functioning	0.82	10.12	8.62
EORTC QLQ-LC13 Dyspnea	0.77	10.81	10.29
EORTC QLQ-LC13 Coughing	0.76	13.67	13.42
EORTC QLQ-LC13 Pain in Chest	0.62	12.06	14.95

EORTC European Organisation for Research and Treatment of Cancer, QLQ-C30 30-item core instrument, QLQ-LC13 13-item lung cancer module

^aTest–retest reliability is the intraclass correlation coefficient using a two-way mixed effects regression model based on absolute agreement with screening data as the ‘test’ administration and Week 1 data as the ‘retest’ administration, using only participants who report the same value on the Global Health Status item at both administrations

^b Based on Baseline scores