Lung function decline rates according to GOLD group in patients with chronic obstructive pulmonary disease

Figures & data

Table 1 Baseline patient characteristics and long-term outcomes

	Total (n=175)	GOLD group
		A (n=58)	B (n=45)	C (n=15)	D (n=57)
Age (years)	66.4±7.1	66.1±7.6	64.9±6.6	68.8±6.4	67.2±7.0
Males (%)	169 (96.6%)	57 (98.3%)	42 (93.3%)	15 (100%)	55 (96.5%)
Height (cm)	165.5±6.4	165.9±5.9	165.2±6.1	168.2±6.1	164.4±6.9
Weight (kg)	64.1±10.3	67.1±11.3	65.2±7.9	63.1±7.0	60.4±10.7
Body mass index	23.3±3.2	24.2±3.2	23.9±2.7	22.3±2.6	22.3±3.4
Smoking status
Current smoker	54 (30.9%)	22 (37.9%)	12 (26.7%)	2 (13.3%)	18 (31.6%)
Pack-year	48.5±26.7	50.1±28.6	52.9±28.2	37.6±18.2	46.4±24.9
SGRQ score	29.9±17.7	14.9±7.2	36.5±14.3	18.8±4.8	43.4±16.4
mMRC grade
0	35 (20.0%)	27 (46.6%)	4 (8.9%)	4 (26.7%)	0
1	72 (41.1%)	31 (53.5%)	13 (28.9%)	11 (73.3%)	17 (29.8%)
2	52 (29.7%)	0	23 (51.1%)	0	29 (50.9%)
3	12 (6.9%)	0	4 (8.9%)	0	8 (14.0%)
4	4 (2.3%)	0	1 (2.2%)	0	3 (5.3%)
Spirometry
Prebronchodilator
FEV1 (L)	1.59±0.54	1.96±0.45	1.80±0.43	1.38±0.41	1.11±0.30
FEV1 (% predicted)	52.3±15.7	63.6±11.6	58.4±10.7	44.6±12.7	38.0±10.5
FVC (L)	3.35±0.77	3.65±0.68	3.63±0.73	3.10±0.66	2.88±0.67
FVC (% predicted)	79.6±15.8	85.5±14.2	86.2±12.8	71.5±14.0	70.4±14.6
Postbronchodilator
FEV1 (L)	1.70±0.55	2.07±0.45	1.92±0.42	1.53±0.37	1.20±0.32
FEV1 (% predicted)	55.8±15.6	67.1±11.1	62.4±9.6	49.3±11.3	40.8±10.9
FVC (L)	3.48±0.77	3.78±0.66	3.81±0.76	3.23±0.63	2.99±0.62
FVC (% predicted)	82.7±15.6	88.5±13.8	90.4±13.6	74.4±12.6	73.0±13.4
DLCO (% predicted)	81.5±25.0	90.2±24.4	75.8±20.7	85.4±19.9	76.2±27.7
TLC (L)	6.34±1.08	6.11±0.88	6.29±1.04	6.51±1.47	6.57±1.16
TLC (% predicted)	114.3±18.0	108.9±16.7	113.3±16.1	112.3±17.4	121.2±19.2
RV (L)	2.89±0.99	2.35±0.73	2.59±0.78	3.31±1.08	3.59±0.91
RV (% predicted)	134.6±46.1	109.2±33.8	123.0±39.4	144.7±41.5	167.6±43.6
RV/TLC (%)	45.1±11.1	38.0±9.1	40.8±8.8	50.2±6.92	54.4±8.0
GOLD stage
I	13 (7.4%)	10 (17.2%)	2 (4.4%)	1 (6.7%)	0
II	98 (56.0%)	48 (82.8%)	43 (95.6%)	2 (13.3%)	5 (8.8%)
III	56 (32.0%)	0	0	12 (80.0%)	44 (77.2%)
IV	8 (4.6%)	0	0	0	8 (14.0%)
Drugs
ICS/LABA use	157 (89.7%)	45 (77.6%)	43 (95.6%)	15 (100%)	54 (94.7%)
ICS/LABA MPR	0.73±0.39	0.53±0.45	0.80±0.32	0.71±0.38	0.87±0.29
LAMA use	146 (83.4%)	44 (75.9%)	38 (84.4%)	12 (80%)	52 (91.2%)
LAMA MPR	0.67±0.41	0.63±0.43	0.57±0.42	0.70±0.44	0.80±0.35
ICS/LABA and LAMA combination	130 (74.3%)	32 (55.2%)	37 (82.2%)	12 (80.0%)	49 (85.9%)
Exacerbation in previous year	0.57±2.23	0.07±0.26	0.18±0.39	0.93±2.13	1.28±3.61
Severe exacerbation in previous yeara	0.11±0.50	0	0	0.27±0.59	0.28±0.80

Notes: Data are presented as n (%) or the mean ± standard deviation (range).

a Exacerbations requiring hospitalization or an emergency department visit.

Abbreviations: DLCO, diffusing capacity for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting β-agonist; LAMA, long-acting muscarinic antagonist; mMRC, modified Medical Round Council; MPR, medication possession ratio; RV, residual volume; SGRQ, St George’s Respiratory Questionnaire; TLC, total lung capacity.

Table 2 Annual rate of decline in postbronchodilator FEV₁ and FVC (mL/year)

Patient categories	Patients (n)	Unadjusted		Adjusteda
		Rate (mL/year)	P-value	Rate (mL/year)	P-value
FEV1
Total patients	175	−25.8±3.8		−28.3±4.9
GOLD group			0.474		0.467
A	58	−32.9±6.3		−34.4±7.9
B	45	−27.4±7.4		−26.2±9.4
C	15	−22.8±12.9		−22.7±16.0
D	57	−18.3±6.9		−24.0±8.7
Sympto m group			0.255		0.444
Less	73	−30.9±5.7		−32.3±7.2
More	102	−22.2±5.1		−25.0±6.5
Risk group			0.145		0.443
Low	103	−30.6±4.8		−31.0±6.1
High	72	−19.2±6.1		−23.6±7.7
GOLD stage			<0.001		<0.001
I	13	−78.3±13.5		−79.7±13.8
II	98	−24.5±4.8		−24.3±4.9
III	56	−21.4±6.6		−21.7±6.8
IV	8	3.9±20.9		3.0±21.2
FVC
Total patients	175	−27.9±7.3		−26.8±8.6
GOLD group			0.463		0.477
A	58	−42.7±12.0		−41.9±13.8
B	45	−21.4±14.2		−11.2±16.3
C	15	−32.9±24.7		−34.1±27.8
D	57	−16.1±13.2		−19.3±15.1
Symptom group			0.118		0.129
Less	73	−40.8±10.8		−40.4±12.4
More	102	−18.0±9.7		−15.6±11.2
Risk group			0.345		0.699
Low	103	−33.8±9.2		−29.2±10.7
High	72	−19.7±11.7		−22.7±13.4
GOLD stage			0.195		0.191
I	13	−81.3±26.3		−81.2±26.3
II	98	−25.1±9.4		−25.3±9.4
III	56	−24.5±12.9		−24.8±12.9
IV	8	−2.1±40.2		0.8±40.2

Notes: Data are the mean ± standard deviation (range).

a Adjusted by age, sex, height, weight, smoking status, and the medication possession ratio of respiratory medications (inhaled corticosteroid/long acting β-agonist and long-acting muscarinic antagonist).

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 3 Annual rate of percentage decline in postbronchodilator FEV₁ and FVC (%/year)

Patients categories	Patients (n)	Unadjusted		Adjusteda
		Rate (%/year)	P-value	Rate (%/year)	P-value
FEV1
Total patients	175	−0.40±0.25		−0.52±0.33
GOLD group			0.981		0.941
A	58	−0.27±0.21		−0.34±0.26
B	45	−0.16±0.25		−0.12±0.31
C	15	−0.16±0.44		−0.19±0.53
D	57	−0.17±0.23		−0.34±0.29
Symptom group			0.708
Less	73	−0.25±0.19		−0.21±0.24	0.798
More	102	−0.16±0.17		−0.23±0.22
Risk group			0.813		0.858
Low	103	−0.23±0.16		−0.25±0.20
High	72	−0.16±0.21		−0.31±0.26
GOLD stage			0.021		0.022
I	13	−1.54±0.47		−1.53±0.47
II	98	−0.06±0.17		−0.06±0.17
III	56	−0.26±0.23		−0.26±0.23
IV	8	0.49±0.73		0.48±0.73
FVC
Total patients	175	−0.66±0.34		−0.64±0.41
GOLD group			0.436		0.463
A	58	−0.68±0.28		−0.67±0.33
B	45	−0.15±0.33		0.08±0.39
C	15	−0.55±0.58		−0.57±0.66
D	57	−0.05±0.31		−0.18±0.36
Symptom group			0.102		0.127
Less	73	−0.65±0.26		−0.65±0.29
More	102	−0.08±0.23		−0.06±0.27
Risk group			0.401		0.828
Low	103	−0.46±0.22		−0.36±0.25
High	72	−0.16±0.28		−0.27±0.32
GOLD stage			0.213		0.215
I	13	−1.55±0.63		−1.54±0.62
II	98	−0.24±0.22		−0.24±0.22
III	56	−0.32±0.31		−0.32±0.31
IV	8	0.37±0.96		0.38±0.96

Notes: Data are the mean ± standard deviation (range).

a Adjusted by age, sex, height, weight, smoking status, and medication possession ratio of respiratory medications (inhaled corticosteroid-long acting β-agonist and long-acting muscarinic antagonist).

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 4 Annual rate of decline in postbronchodilator FEV₁/FVC, DLCO, and RV/TLC (%/year)

Patients categories	Patients (n)	Unadjusted		Adjusteda
		Rate (%/year)	P-value	Rate (%/year)	P-value
FEV1/FVC (%)
Total patients	175	−0.07±2.59		−0.41±0.11
GOLD group			0.561		0.576
A	58	−0.24±0.43		−0.25±0.18
B	45	−0.48±0.51		−0.53±0.22
C	15	−0.29±0.88		−0.30±0.37
D	57	0.44±0.47		−0.60±0.20
GOLD stage			0.536		0.521
I	13	−0.63±0.93		−0.65±0.94
II	98	−0.34±0.34		−0.36±0.4
III	56	0.43±0.46		0.43±0.46
IV	8	0.11±1.41		0.16±1.42
DLCO (%)
Total patients	175	−0.95±0.33		−1.02±0.38
GOLD group			0.317		0.278
A	58	−0.57±0.54		−0.44±0.62
B	45	−1.51±0.64		−1.81±0.73
C	15	0.54±1.09		0.36±1.23
D	57	−1.34±0.59		−1.49±0.68
GOLD stage			0.320		0.315
I	13	−1.54±1.18		−1.54±1.18
II	98	−0.69±0.43		−0.70±0.43
III	56	−0.99±0.59		−1.00±0.59
IV	8	−4.14±1.88		−4.16±1.87
RV/TLC (%)
Total patients	175	−0.33±0.21		−0.40±0.23
GOLD group			0.526		0.482
A	58	−0.59±0.35		−0.69±0.37
B	45	−0.51±0.41		−0.62±0.44
C	15	0.08±0.71		−0.09±0.74
D	57	0.09±0.39		0.09±0.42
GOLD stage			0.436		0.429
I	13	0.14±0.78		0.19±0.78
II	98	−0.59±0.27		−0.58±0.27
III	56	0.13±0.38		0.13±0.38
IV	8	−0.35±1.26		−0.41±1.26

Notes: Data are the mean ± standard deviation (range).

a Adjusted by age, sex, height, weight, smoking status, and medication possession ratio of respiratory medications (ICS-LABA and LAMA).

Abbreviations: DLCO, diffusing capacity for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting β-agonist; LAMA, long-acting muscarinic antagonist; RV, residual volume; TLC, total lung capacity.

Figure 1 Annual rate of decline in postbronchodilator FEV₁ adjusted by age, sex, height, weight, smoking status, and medication possession ratio of respiratory medications (ICS-LABA and LAMA).

Notes: (A) Among GOLD groups (A–D). (B) Among GOLD stages (I–IV).
Abbreviations: FEV₁, forced expiratory volume in 1 second; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS-LABA, inhaled corticosteroid/long-acting β-agonist; LAMA, long-acting muscarinic antagonist.