Combined Therapy with Tiotropium and Formoterol in Chronic Obstructive Pulmonary Disease: Effect on the 6-Minute Walk Test

Figures & data

Figure 1.  Flow diagram.

Table 1.  Baseline characteristics

Variable
n	38
Men n(%)	23 (60)
Age (yrs)	64.3 (8.7)
BMI (kg·m^2)	27 (12)
Current, n	14
Ex-smoker, n	24
Pack-years	40 (17)
Medication,% ICS,	70
Mean dose in subjects receiving ICS, fluticasone equivalent, ucg	590 (265)
% on tiotropium for more than 4 weeks at study entry	60
symptoms: dyspnoea (MMRC scale) #	2 (3)
FEV1 (L)post-BD	1.37 (0.42)
FEV1 (%) pred, post-BD	53 (16.2)
FVC (L)post-BD	3.0 (0.80)
FEV1/VC,%	46 (10)
IC (L) post-BD	2.26 (0.64)
6MWT distance (m)	375 (90)
SGRQ symptoms	48.7 (24.3)
SGRQ impact	29.5 (7.8)
SGRQ activity	60.7 (23.2)
SGRQ total score	42.1 (18.4)
BODE index	2.37 (1.1)

mean (sd); # median (IQR); n: number, yrs: years,% percentage, ICS inhaled corticosteroid dose, ucg: micrograms, MMRC: Modified Medical Research Council scale, FEV₁ post-BD: forced expiratory volume in one second post bronchodilator (BD), L: litres; pred: predicted, FVC: forced vital capacity, IC: inspiratory capacity, 6MWT: six minute walk test, m: metres, SGQR: St George's Respiratory Questionnaire, BODE index: Body–mass index, Airflow obstruction Dyspnoea, Exercise capacity.

Table 2.  Outcome variables: Exercise capacity, lung function and symptoms

	T + Formoterol n = 38	T+placebo n = 36	Difference in change	p-value
Change in exercise 6-minute walk test, metres	25.5(4.4, 46.5)	−7.6(−23.1, 7.8)	36.3(2.4, 70.1)	0.04
FEV1, L post-BD	0.16(0.00, 0.31)	0.03(−0.11, 0.17)	0.11(−0.10, 0.32)	0.07
FVC, L post-BD	0.12(−0.01, 0.26)	0.14(−0.07, 0.34)	−0.04(−0.30, 0.22)	0.70
Inspiratory Capacity, L	−0.036(−0.13–0.0.058)	0.018(−0.056–0.093)	0.05(−0.182–0.082)	0.45
Symptoms, MMRC^#	−0.1(−0.3,0.1)	0.1(−0.2,0.3)	−0.2(−0.54, 0.14)	0.13

Data presented are mean (95% C.I.) unless specified; # median (IQR); T: tiotropium, FEV₁: forced expiratory volume in one second post bronchodilator (BD), L: litres; FVC: forced vital capacity, MMRC: Modified Medical Research Council scale.

Table 3.  Health-related quality of life (SGRQ)

	T+Formoterol	T+placebo	Difference in change	p-value
Change in activity	0.5(−2.9, 4.0)	−0.5(−3.2, 2.2)	1.6(−3.2, 6.4)	0.45
Change in impact	−0.4(−3.5, 2.6)	−0.6(−4.1, 2.9)	0.3(−4.2, 4.8)	0.90
Change in symptom	−5.5(−11.4, 0.4)	1.2(−4.2, 6.7)	−6.7(−15.7, 2.3)	0.13
Change in total scores	−1.0(−3.7, 1.7)	−0.5(−2.8, 1.7)	−0.2(−3.6, 3.2)	0.89

Data presented are mean (95% C.I.)