Table 6.

Sensitivity analysis for non-smokers: mean (SE) postbronchodilator FEV1 decline in ml/year in the three categories* based on alternative LLN prediction equations for the base case population

		Category*
		Non-obstructed	Discordant	Obstructed	p-value†
		(LLN-Fixed-)	(LLN-Fixed+)	(LLN+Fixed+)	Overall difference between categories	LLN-Fixed+ versus LLN-Fixed-	LLN-Fixed+ versus LLN+Fixed+
Swanney [6], 2008	FEV1 decline	-15 (1)	-17 (4)	-36 (4)	< 0.001	0.624	< 0.001
	n	1,828	251	237
ECSC [25], 1993	FEV1 decline	-15 (1)	-15 (8)	-28 (3)	< 0.001	0.975	0.132
	n	1,831	71	426
Kuster [28], 2008	FEV1 decline	-15 (1)	-8 (12)	-26 (3)	< 0.001	0.076	0.009
	n	1,814	28	532
Falaschetti [26], 2004	FEV1 decline	-15 (1)	-22 (8)	-27 (3)	< 0.001	0.376	0.521
	n	1,785	71	488
Brandli [27], 2000	FEV1 decline	-15 (1)	-17 (6)	-31 (3)	< 0.001	0.746	0.036
	n	1,828	125	349
Hankinson [29], 1999	FEV1 decline	-15 (1)	-7 (10)	-26 (3)	< 0.001	0.424	0.061
	n	1,816	46	482

ECSC: European Community for Steel and Coal; FEV₁: forced expiratory volume in 1 s; LLN: lower limit of normal; SD: standard deviation

* based on reference equations for LLN as indicated in first column

† between group differences were analyzed using random coefficient regression models with random intercept and random slope; adjustment for inhaled corticosteroid use