The Correlation of Sit-to-Stand Tests with COPD Assessment Test and GOLD Staging Classification

Figures & data

Figure 1. Patient Selection: CONSORT diagram.

Table 1. Patients characteristics and comparison between groups of patients who completed or failed to complete the sit-to-stand tests (5STST and 30s-STST).

Characteristic	Total (n = 60)	Completed (n = 42)	Failed (n = 18)	p-value
Age (y)	67.2 ± 7.2	62.7 ± 12.8	68.2 ± 5.4	0.429
Sex, male (%)	32 (53%)	22 (53%)	10 (56%)	0.523
BMI (kg/m2)	27.4 ± 5.2	28.0 ± 5.9	26.0 ± 2.8	0.183
FEV1 (L)	1.35 ± 0.55	1.37 ± 0.51	1.30 ± 0.65	0.561
FEV1% (% predicted)	53 ± 18	53 ± 19	53 ± 17	0.923
FEV1/FVC (%)	51 ± 14	51 ± 13	52 ± 19	0.285
GOLD I/II/III/IV (%)	7 (12)/24(40)/23(38)/6(10)	5(12)/15(36)/18(43)/4(9)	2(11)/9(50)/5(28)/2(11)	>0.05
A/B/C/D (%)	9(15)/22(37)/6(10)/23(38)	8(19)/18(43)/4(9.5)/12(28.5)	1(6)/4(22)/2(11)/11(61)	<0.05
CAT score	20.58 ± 9.06	19.14 ± 9.19	23.94 ± 8.01	<0.05
Previous COPD exacerbations	1.76 ± 1.75	1.3 ± 1.48	2.83 ± 1.88	<0.01
Previous hospitalizations for COPD	0.60 ± 0.88	0.43 ± 0.73	1 ± 1.08	<0.05
30s-STST (n)		12.85 ± 5.08
5STST (sec)		13.1 ± 3.79
Current Smokers	7	6	2	0.529
Ex Smokers	42	32	10	0.123
Comorbidity
Cardiovascular disease	16	12	4	0.633
Hypertension	45	32	13	0.830
Diabetes mellitus	17	12	5	0.134
Dyslipidemia	37	27	10	0.914
Gastrointestinal disorders	13	10	3	0.722

Table 1: Demographics and Baseline Characteristics. Continuous variables are expressed as mean values ± SDs.

5STST (5 Repetition Sit-to-Stand Test), 30s-STST (30s Sit-to-Stand Test), ACS (Acute Coronary Syndromes), BMI (Body Mass Index), CAT (COPD Assessment Test), COPD (Chronic Obstructive Lung Disease), FEV1 (Forced Expiration Volume in 1s), FVC (Forced Vital Capacity), GOLD (Global Initiative for Obstructive Lung Disease), SD (Standard Deviation).

Table 2. Comparison of sit-to-stand (5STST and 30s-STST) measurements between patients with fewer and more symptoms and between patients with low and high risk of future exacerbations.

GOLD Group	A	B	C	D	p-value
5STST (sec)	11.9 ± 5.8	11.7 ± 2.2	12 ± 2.3	16.5 ± 2.4	<0.05
30s-STST (n)	17 ± 9	13 ± 3	16 ± 4	9 ± 1	<0.05
Characteristic	Low risk of exacerbations		High risk of exacerbations
5STST (sec)	11.8 ± 3.5		15.5 ± 3.1		<0.01
30s-STST (n)	14 ± 5		11 ± 4		<0.01
Characteristic	Less symptomatic	More symptomatic	Less symptomatic	More symptomatic
5STST (sec)	12 ± 5		14 ± 3		0.314
30s-STST (n)	17 ± 7		11.5 ± 3		<0.05

5STST (5 Repetition Sit-to-Stand Test), 30s-STST (30s Sit-to-Stand Test), COPD (Chronic Obstructive Lung Disease), GOLD (Global Initiative for Obstructive Lung Disease), SD (Standard Deviation).

Figure 2. Correlation between COPD assessment test (CAT) and (A) the time to perform 5STST, and (B) the number of stands during 30s-STST.

Table 3. Spearman rank correlation of sit-to-stand tests (5STST and 30s-STST) with various clinical and spirometric parameters.

Variables	5STST (sec)	30s-STST (n)
Age (y)	ρ = 0.334, Ρ < 0.05	ρ= −0.309, Ρ < 0.05
Sex	ρ = −0.160, Ρ = 0.312	ρ = 0.203, Ρ = 0.196
BMI (kg/m2)	ρ= −0.153, Ρ = 0.333	ρ = 0.063, Ρ = 0.694
FEV1% (% predicted)	ρ= −0.497, Ρ < 0.01	ρ = 0.419, Ρ < 0.01
CAT	ρ = 0.318, Ρ < 0.05	ρ= −0.478, Ρ < 0.01
Previous COPD exacerbations	ρ = 0.421, Ρ < 0.01	ρ= −0.320, Ρ < 0.05
Previous COPD hospitalizations	ρ = 0.321, Ρ < 0.05	ρ= −0.201, Ρ = 0.201

5STST (5 Repetition Sit-to-Stand Test), 30s-STST (30s Sit-to-Stand Test), BMI (Body Mass Index), CAT (COPD Assessment Test), COPD (Chronic Obstructive Lung Disease), FEV1 (Forced Expiration Volume in 1s).

Table 4. Results of multivariate linear regression analysis of the association of the time to complete the 5STST with multiple predictors.

Predictive parameter	Regression coefficient				P
	Value	SEM	95%CI	Standardised
Age (years)	0,212	0,068	0.075, 0.350	0.475	0,005
FEV1 (% predicted)	−0,107	0,036	−0.179, −0.034	−0.517	0,005
CAT Score	0,144	0,063	0.017, 0.270	0.349	0,027
Previous COPD Exacerbations	−0,202	0,587	−1.398, 0.993	−0.080	0,732
Previous COPD hospitalizations	−0.253	1.145	−2.584, 2.079	−0.049	0.827

5STST (5 Repetition Sit-to-Stand Test), CAT (COPD Assessment Test), CI (Confidence Interval), COPD (Chronic Obstructive Lung Disease), FEV1 (Forced Expiration Volume in 1s), GOLD (Global Initiative for Obstructive Lung Disease), SEM (Standard Error of the Mean).

Table 5. Results of multivariate linear regression analysis of the association of the repetitions of the sit-to-stand maneuver completed in the 30s-STST with multiple predictors.

Predictive parameter	Regression coefficient				P
	Value	SEM	95%CI	Standardised
Age (years)	−0,255	0,087	−0.441, −0.063	−0.423	0,006
FEV1 (% predicted)	0,054	0,041	−0.029, 0.137	0.226	0,196
CAT Score	−0,254	0,08	−0.517, −0.043	−0.461	0,003
Previous COPD Exacerbations	0,369	0,674	−0.998, 1.735	0.108	0,588

30s-STST (30s Sit-to-Stand Test), CAT (COPD Assessment Test), CI (Confidence Interval), COPD (Chronic Obstructive Lung Disease), FEV1 (Forced Expiration Volume in 1s), GOLD (Global Initiative for Obstructive Lung Disease), SEM (Standard Error of the Mean).

Table 6. Spearman rank correlation of STST (5STST and 30s-STST) with CAT items.

CAT items	5STST (sec)	30s-STST (n)
1) Cough	ρ= −0.032, Ρ = 0.843	ρ= −0.098, Ρ = 0.546
2) Phlegm	ρ = 0.036, Ρ = 0.843	ρ= −0.162, Ρ = 0.317
3) Chest tightness	ρ = 0.062, Ρ = 0.703	ρ= −0.228, Ρ = 0.156
4) Breathlessness	ρ = 0.508, Ρ < 0.01	ρ= −0.511, Ρ < 0.01
5) Limitation of activities	ρ = 0.338, Ρ < 0.05	ρ= −0.427, Ρ < 0.01
6) Lack of confidence	ρ = 0.321, Ρ < 0.05	ρ= −0.510, Ρ < 0.01
7) Sleep	ρ= −0.120, Ρ = 0.462	ρ= −0,074, Ρ = 0.652
8) Lack of Energy	ρ = 0.360, Ρ < 0.05	ρ= −0.442, Ρ < 0.01

5STST (5 Repetition Sit-to-Stand Test), 30s-STST (30s Sit-to-Stand Test), CAT (COPD Assessment Test).

Table 7. Results of multivariate linear regression analysis of the association of the time to complete the 5STST with different CAT items.

Predictive parameter	Regression coefficient				P
	Value	SEM	95%CI	Standardised
Breathlessness	1.821	0,544	0.717, 2.924	0.664	0,002
Limitation of activities	0,655	0,419	−1.506, 0.196	−0.345	0,127
Lack of confidence	0,677	0,304	0.060, 1.294	0.346	0,032
Lack of energy	0,203	0,294	−0.394, 0.799	0.100	0,495

5STST (5 Repetition Sit-to-Stand Test), CI (Confidence Interval), CAT (COPD Assessment Test), COPD (Chronic Obstructive Lung Disease), SEM (Standard Error of the Mean).

Table 8. Results of multivariate linear regression analysis of the association of the repetitions of the 30s-STST with different CAT items.

Predictive parameter	Regression coefficient				P
	Value	SEM	95%CI	Standardised
Breathlessness	−3,14	0,574	−4.304, −1.975	−5.472	0,000
Limitation of activities	− 1,229	0,442	−2.127, −0.331	−2.780	0,009
Lack of confidence	−1,028	0,321	−1.679, −0.377	−3.206	0,003
Lack of energy	−0,422	0,310	−1.052, 0.207	−1.362	0,182

30s-STST (30s Sit-to-Stand Test), CI (Confidence Interval), CAT (COPD Assessment Test), COPD (Chronic Obstructive Lung Disease), SEM (Standard Error of the Mean).