Lung function decline in relation to diagnostic criteria for airflow obstruction in respiratory symptomatic subjects

Table 5 Sensitivity analysis for 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	-21 (3)	-21 (7)	-50 (5)	< 0.001	0.973	< 0.001
	n	578	138	292
ECSC [25], 1993	FEV1 decline	-22 (3)	-24 (15)	-50 (3)	< 0.001	0.870	0.094
	n	578	29	452
Kuster [28], 2008	FEV1 decline	-20 (3)	-8 (20)	-48 (3)	< 0.001	0.599	0.087
	n	563	14	557
Falaschetti [26], 2004	FEV1 decline	-21 (3)	-21 (18)	-47 (3)	< 0.001	0.985	0.153
	n	546	24	542
Brandli [27], 2000	FEV1 decline	-21 (3)	-4 (11)	-49 (4)	< 0.001	0.026	< 0.001
	n	575	60	397
Hankinson [29], 1999	FEV1 decline	-21 (3)	-37 (22)	-48 (3)	< 0.001	0.468	0.620
	n	569	18	523

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

ISSN: 1471-2466