Comparison of the clinical characteristics and comprehensive assessments of the 2011 and 2017 GOLD classifications for patients with COPD in China

Figures & data

Table 1 Patient characteristics at baseline

Age (years)	67.52±10.55
Male subjects, n (%)	512 (81.1%)
BMI (kg/m^2)	22.17±3.81
Non-hospitalization, n (%)	389 (61.6%)
Smoking status
Smoking index (pack-years)	26.12±27.62
Never-smoker, n (%)	197 (31.2%)
Former smoker, n (%)	230 (36.5%)
Current smoker, n (%)	204 (32.3%)
Pharmacological therapy
No treatment, n (%)	132 (20.9%)
Bronchodilators, n (%)	182 (28.8%)
ICS, n (%)	55 (8.7%)
Bronchodilators + ICS, n (%)	262 (41.5%)
A-B-C-D group
2011 GOLD, n (A1/B1/C1/D1)	113/80/154/284
2017 GOLD, n (A2/B2/C2/D2)	177/157/90/207

Notes: Continuous variables are presented as the mean±SD; categorical variables are presented as numbers and percentages unless stated otherwise. Groups A₁–D₁ are categories according to the 2011 GOLD; Groups A₂–D₂ are categories according to the 2017 GOLD.

Abbreviations: BMI, body mass index; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid.

Figure 1 Flow chart of study inclusion.

Note: Groups A₁–D₁ were categories according to 2011 GOLD; Groups A₂–D₂ were categories according to 2017 GOLD.
Abbreviation: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 2 Coherence between 2011 GOLD and 2017 GOLD classifications

	2011 GOLD
	A1(n=113)	B1(n=80)	C1(n=154)	D1(n=284)
2017 GOLD
A2 (n=177)	113	0	64	0
B2 (n=157)	0	80	0	77
C2 (n=90)	0	0	90	0
D2 (n=207)	0	0	0	207
Cohen’s kappa = 0.6963

Notes: Groups A₁–D₁ are categories according to the 2011 GOLD; Groups A₂–D₂ are categories according to the 2017 GOLD. The bold numbers indicate the consistency of distribution between the 2011 GOLD and the 2017 GOLD. The underlined numbers indicate the disagreement of distribution between the 2011 GOLD and the 2017 GOLD.

Abbreviation: GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Figure 2 Distribution change of GOLD.

Note: Groups A-D were categories according to 2011 GOLD and 2017 GOLD.
Abbreviation: GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 3 Comparison of comprehensive assessment between the two groups in the same category

	Group A		Group B		Group C		Group D
	A1 (n=113)	A2 (n=177)	B1 (n=80)	B2 (n=157)	C1 (n=154)	C2 (n=90)	D1 (n=284)	D2 (n=207)
Age (years)	66.34±9.02	65.32±9.29	65.55±13.41	66.75±11.70	66.31±9.68	68.29±9.33	69.20±10.46	69.65±10.77
Male/female	(91/22)	(141/36)	(62/18)	(133/24)	(124/30)	(74/16)	(235/49)	(164/43)
Smoking index (pack-years)	22.21±27.89	23.07±26.20	19.98±21.15	27.58±26.90a	24.28±21.75	24.07±20.91	30.41±31.19	28.52±31.51
FEV1 (L)	1.81±0.49	1.53±0.56b	1.59±0.43	1.26±0.49b	1.23±0.45	1.36±0.49a	1.04±0.45	1.08±0.50
FEV1 % pred (%)	73.07±14.76	60.92±20.45b	67.33±10.49	51.88±18.42b	50.82±17.12	58.89±17.63b	44.20±18.47	47.32±20.17
FVC (L)	3.06±0.74	2.73±0.83b	2.76±0.79	2.39±0.76b	2.37±0.72	2.53±0.74	2.20±0.75	2.27±0.81
FEV1/FVC (%)	60.45±9.39	56.54±10.46b	59.20±8.62	52.94±11.09b	52.82±10.50	55.08±11.20	47.43±12.27	47.80±13.15
mMRC	0.48±0.50	0.60±0.49a	2.30±0.56	2.42±0.65	0.79±0.44	0.78±0.47	2.74±0.78	2.81±0.79
CAT	6.93±4.00	7.47±4.00	17.45±5.53	17.46±5.84	8.92±3.77	9.27±3.70	20.51±7.04	21.65±7.02
SGRQ	15.14±7.50	16.81±8.02	28.53±11.14	30.07±11.79	19.46±8.24	19.26±8.37	35.25±13.05	36.58±13.10
6MWD (m)	512.35±69.28	500.71±68.64	437.25±93.57	402.01±99.95b	466.62±75.61	457.00±82.47	360.10±116.92	358.12±124.67
PImax (cm H2O)	69.77±18.81	66.86±19.30	62.22±17.95	55.70±18.11b	59.91±17.67	58.62±16.46	51.19±16.42	52.03±16.63
PEmax (cm H2O)	80.43±24.97	76.42±27.88	68.33±18.58	61.25±17.68b	66.59±25.66	64.64±20.67	58.09±19.33	59.65±20.97
FFMI (kg/m^2)	17.18±1.88	17.22±1.91	16.56±2.46	16.17±2.34	16.81±1.82	16.47±1.62	15.68±2.19	15.65±2.21
BMI (kg/m^2)	23.14±2.52	23.11±2.84	23.15±3.82	22.42±4.24	22.65±3.57	22.36±3.71	21.25±4.14	21.09±3.98
BODE	0.61±0.73	1.37±1.25b	2.13±1.17	3.47±1.83b	2.06±1.37	1.60±1.52a	4.66±1.97	4.58±2.18
HADS	2.63±1.43	2.68±1.45	3.50±1.70	3.69±1.58	3.75±1.55	4.44±1.17b	3.83±1.40	3.81±1.40
HADS depression	1.46±1.14	1.60±1.22	1.80±1.22	1.90±1.25	2.04±1.16	2.17±1.02	1.95±1.13	1.93±1.08
HADS anxiety	1.22±1.05	1.14±0.99	1.70±1.11	1.80±1.11	1.76±1.17	2.30±1.07b	1.89±1.15	1.89±1.17

Notes: Continuous variables are presented as the mean±SD; categorical variables are presented as numbers and percentages unless stated otherwise. Groups A₁–D₁ are categories according to the 2011 GOLD; Groups A₂–D₂ are categories according to the 2017 GOLD.

a Compared with the 2011 GOLD, P<0.05;

b Compared with the 2011 GOLD, P<0.001.

Abbreviations: 6MWD, 6-minute walking distance; % pred, percent predicted; BMI, body mass index; BODE, body mass index, airflow obstruction, dyspnea, and exercise capacity index; CAT, COPD Assessment Test; FFMI, fat-free mass index; HADS, Hospital Anxiety and Depression Scale; mMRC, Modified Medical Research Council Scale; PEmax, maximal expiratory pressure; PImax, maximal inspiratory pressure; SGRQ, St George’s Respiratory Questionnaire.

Table 4 Comparison of comprehensive assessment between Group A and the other three categories in the 2011 GOLD

	A1 (n=113)	B1 (n=80)	C1 (n=154)	D1 (n=284)
FEV1 (L)	0.00 (Ref)	−0.22 (−0.35 to −0.09)b	−0.58 (−0.69 to −0.47)b	−0.75 (−0.85 to −0.65)b
FEV1 % pred (%)	0.00 (Ref)	−6.14 (−10.72 to −1.57)a	−22.15 (−26.03 to −18.28)b	−29.08 (−32.59 to −25.56)b
FVC1 (L)	0.00 (Ref)	−0.28 (−0.48 to −0.08)a	−0.69 (−0.86 to −0.52)b	−0.83 (−0.99 to −0.68)b
FEV1/FVC (%)	0.00 (Ref)	−1.56 (−4.61 to 1.49)	−7.54 (−10.12 to −4.95)b	−12.81 (−15.15 to −10.46)b
mMRC	0.00 (Ref)	1.83 (1.64 to 2.01)b	0.31 (0.16 to 0.47)b	2.26 (2.12 to 2.40)b
CAT	0.00 (Ref)	10.53 (8.90 to 12.15)b	1.93 (0.55 to 3.31)a	13.32 (12.07 to 14.57)b
SGRQ	0.00 (Ref)	13.22 (10.11 to 16.33)b	4.24 (1.61 to 6.88)a	20.09 (17.70 to 22.48)b
6MWD (100 m)	0.00 (Ref)	−0.77 (−1.04 to −0.51)b	−0.46 (−0.68 to −0.23)b	−1.43 (−1.64 to −1.23)b
PImax (cm H2O)	0.00 (Ref)	−7.72 (−12.46 to −2.98)a	−9.76 (−13.78 to −5.75)b	−16.92 (−20.56 to −13.28)b
PEmax (cm H2O)	0.00 (Ref)	−12.55 (−18.62 to −6.47)b	−13.78 (−18.93 to −8.63)b	−20.39 (−25.06 to −15.72)b
FFMI (kg/m^2)	0.00 (Ref)	−0.58 (−1.17 to −0.00)a	−0.36 (−0.86 to 0.13)	−1.43 (−1.88 to −0.98)a
BMI (kg/m^2)	0.00 (Ref)	−0.09 (−1.14 to 0.97)	−0.47 (−1.37 to 0.43)	−1.69 (−2.50 to −0.88)a
BODE	0.00 (Ref)	1.55 (1.11 to 2.00)b	1.45 (1.07 to 1.83)b	4.01 (3.67 to 4.35)b
HADS	0.00 (Ref)	0.87 (0.45 to 1.30)b	1.12 (0.76 to 1.48)b	1.15 (0.83 to 1.48)b
HADS depression	0.00 (Ref)	0.35 (0.04 to 0.68)a	0.58 (0.30 to 0.86)b	0.46 (0.21 to 0.72)b
HADS anxiety	0.00 (Ref)	0.47 (0.15 to 0.79)a	0.54 (0.26 to 0.81)b	0.66 (0.41 to 0.91)b

Notes: Groups A₁–D₁ are categories according to the 2011 GOLD. Data are presented as regression coefficient (95% CI) unless stated otherwise. Bold numbers indicate statistical significance when Group A₁, which was set as the reference (Ref), was compared with the other three categories (as dummy variables) after adjusting for age, sex, and smoking index.

a Compared with Group A₁, P<0.05;

b Compared with Group A₁, P<0.001.

Abbreviations: 6MWD, 6-minute walking distance; % pred, percent predicted; BMI, body mass index; BODE, body mass index, airflow obstruction, dyspnea, and exercise capacity index; CAT, COPD Assessment Test; FFMI, fat-free mass index; GOLD, Global Initiative for Chronic Obstructive Lung Disease; HADS, Hospital Anxiety and Depression Scale; mMRC, Modified Medical Research Council Scale; PEmax, maximal expiratory pressure; PImax, maximal inspiratory pressure; SGRQ, St George’s Respiratory Questionnaire.

Table 5 Comparison of comprehensive assessment between Group A and the other three categories in the 2017 GOLD

	A2 (n=177)	B2 (n=157)	C2 (n=90)	D2 (n=207)
FEV1 (L)	0.00 (Ref)	−0.26 (−0.37 to −0.15)b	−0.14 (−0.27 to −0.01)a	−0.40 (−0.51 to −0.30)b
FEV1 % pred (%)	0.00 (Ref)	−8.78 (−12.83 to −4.73)b	−2.40 (−7.19 to 2.38)	−14.14 (−17.97 to −10.31)b
FVC (L)	0.00 (Ref)	−0.33 (−0.49 to −0.16)b	−0.16 (−0.35 to 0.03)	−0.39 (−0.54 to −0.23)b
FEV1/FVC (%)	0.00 (Ref)	−3.32 (−5.75 to −0.90)a	−1.50 (−4.37 to 1.37)	−8.74 (−11.04 to −6.45)b
mMRC	0.00 (Ref)	1.82 (1.68 to 1.96)b	0.18 (0.02 to 0.34)a	2.21 (2.08 to 2.34)b
CAT	0.00 (Ref)	9.86 (8.67 to 11.05)b	1.77 (0.37 to 3.18)a	13.97 (12.85 to 15.10)b
SGRQ	0.00 (Ref)	13.26 (10.92 to 15.59)b	2.73 (−0.03 to 5.49)	19.90 (17.70 to 22.11)b
6MWD (100 m)	0.00 (Ref)	−0.94 (−1.14 to −0.73)b	−0.35 (−0.60 to −0.11)a	−1.29 (−1.49 to −1.10)b
PImax (cm H2O)	0.00 (Ref)	−10.33 (−13.97 to −6.68)b	−6.89 (−11.20 to −2.57)a	−12.42 (−15.87 to −8.97)b
PEmax (cm H2O)	0.00 (Ref)	−14.14 (−18.79 to −9.49)b	−10.06 (−15.56 to −4.57)b	−13.98 (−18.38 to −9.59)b
FFMI (kg/m^2)	0.00 (Ref)	−1.03 (−1.47 to −0.59)b	−0.72 (−1.23 to −0.20)a	−1.45 (−1.87 to −1.04)b
BMI (kg/m^2)	0.00 (Ref)	−0.57 (−1.37 to 0.22)	−0.63 (−1.57 to 0.31)	−1.80 (−2.56 to −1.05)b
BODE	0.00 (Ref)	2.05 (1.67 to 2.43)b	0.19 (−0.26 to 0.63)	3.15 (2.79 to 3.51)b
HADS	0.00 (Ref)	0.99 (0.68 to 1.30)b	1.74 (1.38 to 2.10)b	1.07 (0.78 to 1.36)b
HADS depression	0.00 (Ref)	0.28 (0.03 to 0.53)a	0.56 (0.27 to 0.86)b	0.30 (0.07 to 0.54)a
HADS anxiety	0.00 (Ref)	0.65 (0.42 to 0.89)b	1.14 (0.87 to 1.42)b	0.73 (0.50 to 0.95)b

Notes: Groups A₂–D₂ are categories according to the 2017 GOLD. Data are presented as regression coefficient (95% CI) unless stated otherwise. Bold numbers indicate statistical significance when Group A₂, which was set as the reference (Ref), was compared with the other three categories (as dummy variables) after adjusting for age, sex, and smoking index.

a Compared with Group A₂, P<0.05;

b Compared with Group A₂, P<0.001.

Abbreviations: % pred, percent predicted; 6MWD, 6-minute walking distance; BMI, body mass index; BODE, body mass index, airflow obstruction, dyspnea, and exercise capacity index; CAT, COPD Assessment Test; FFMI, fat-free mass index; GOLD, Global Initiative for Chronic Obstructive Lung Disease; HADS, Hospital Anxiety and Depression Scale; mMRC, Modified Medical Research Council Scale; PEmax, maximal expiratory pressure; PImax, maximal inspiratory pressure; SGRQ, St George’s Respiratory Questionnaire.