The relationship between cough-specific quality of life and abdominal muscle endurance, fatigue, and depression in patients with COPD

Figures & data

Table 1 Characteristics of COPD patients

Variable	Mean ± SD
Age (years)	60.6±8.7
Sex (male/female)	22/6
Height (cm)	166.4±8.4
Body weight (kg)	75.3±17.6
Body mass index (kg/m^2)	27.1±5.5
FEV1 (%)	53.7±24.9
FVC (%)	69.9±10.6
FEV1/FVC (%)	59.3±15.1
FEF25%–75% (%)	33.0±21.7
PEF (%)	58.3±25.5
Smoking history (pack-years)	40.2±30.8
	Median (minimum–maximum)
Number of exacerbations (n)	0 (0–2)
MMRC (0–4)	1.5 (0–3)

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; FEF_25%–75%, forced expiratory flow between 25% and 75% of FVC; PEF, peak expiratory flow; MMRC, Modified Medical Research Council Dyspnea Scale; SD, standard deviation.

Table 2 Abdominal muscle endurance, cough-specific quality of life, fatigue perception, and depression level in patients with COPD

Variable	Mean ± SD
Number of sit-ups (n)	17.0±5.7
LCQ-total score (3–21)	15.9±3.8
Physical score	5.2±1.2
Social score	5.6±1.6
Psychological score	5.1±1.2
FIS-total score (0–160)	40.0±30.7
Physical score	11.4±9.4
Cognitive score	8.7±7.4
Psychosocial score	19.5±14.5
BDI score (0–63)	12.0±9.4

Abbreviations: LCQ, Leicester Cough Questionnaire; FIS, Fatigue Impact Scale; BDI, Beck Depression Inventory; SD, stansard deviation.

Table 3 The correlations between cough-specific quality of life and abdominal muscle endurance, fatigue perception, and depression level in patients with COPD

	Number of sit-ups	FIS-physical score	FIS-cognitive score	FIS-psychosocial score	FIS-total score	BDI score
The LCQ-physical score	r=0.713	–	–	–	r=−0.578	r=−0.553
	P<0.001				P=0.002	P=0.003
The LCQ-social score	r=0.644	–	–	–	r=−0.444	r=−0.475
	P=0.001				P=0.020	P=0.014
The LCQ-psychological score	r=0.687	–	–	–	r=−0.602	r=−0.552
	P<0.001				P=0.001	P=0.003
The LCQ-total score	r=0.704	r=−0.543	r=−0.494	r=−0.566	r=−0.557	r=−0.550
	P<0.001	P=0.003	P=0.009	P=0.002	P=0.003	P=0.004

Abbreviations: LCQ, Leicester Cough Questionnaire; FIS, Fatigue Impact Scale; BDI, Beck Depression Inventory.

Table 4 Multiple linear regression analysis

	R	R^2	Univariate analysis	B	β
FIS total score	0.667	0.444	0.444	19.213	−0.667
Number of sit-ups	0.760	0.577	0.133	13.008	0.424
R^2=0.577, F(2–20) =12.296, P<0.001, constant =289.007

Notes: Dependent variable: LCQ total score; independent variables (if P≤0.015): number of sit-ups, BDI score, FIS total score, FIS physical score, FIS cognitive score, and FIS psychosocial score.

Abbreviations: LCQ, Leicester Cough Questionnaire; FIS, Fatigue Impact Scale; BDI, Beck Depression Inventory.

Figure 1 The relationship between cough-specific quality of life and abdominal muscle endurance.

Abbreviation: LCQ, Leicester Cough Questionnaire.

Figure 2 The relationship between cough-specific quality of life and depression level.

Abbreviations: LCQ, Leicester Cough Questionnaire; BDI, Beck Depression Inventory.

Figure 3 The relationship between cough-specific quality of life and general impact of fatigue on daily living activities.

Abbreviations: LCQ, Leicester Cough Questionnaire; FIS, Fatigue Impact Scale.