Comorbidities, mortality, and management of chronic obstructive pulmonary disease patients who required admissions to public hospitals in Hong Kong – computerized data collection and analysis

Figures & data

Table 1 Demographic characteristics of the subjects (obtained from the first admission within the year 2012) with or without lung function coding

Characteristics	All subjects	GOLD 1	GOLD 2	GOLD 3	GOLD 4	p-value	GOLD 1–4	No lung function coding	p-value	GOLD 1–2	GOLD 3–4	p-value
Number	9,776	85	488	808	537		1,918	7,858		573	1,345
Male (%)	8,079 (82.6)	74 (87.1)	421 (86.3)	743 (92.0)	483 (89.9)	0.044	1,721 (89.7)	6,358 (80.9)	<0.001	495 (86.4)	1,226 (91.2)	0.002
Age (years); mean (SD)	78.0 (9.4); M: 77.0 (9.2); F: 83.1 (8.4)	77.7 (10.8); M: 76.5 (10.8); F: 85.5 (6.6)	77.8 (8.2); M: 77.3 (8.0); F: 80.7 (8.9)	76.0 (8.3); M: 75.5 (8.3); F: 80.8 (6.4)	73.4 (8.6); M: 72.9 (8.3); F: 77.4 (10.3)	GOLD 1 vs 4, p=0.004; GOLD 2 vs 3, p=0.001; GOLD 2 vs 4 & 3 vs 4, p<0.001	75.8 (8.6); M: 75.3 (8.5); F: 80.1 (8.7)	78.6 (9.4); M: 77.4 (9.3); F: 83.5 (8.3)	<0.001	77.8 (8.7); M: 77.2 (8.5); F: 81.4 (8.8)	74.9 (8.5); M: 74.5 (8.4); F: 79.2 (8.6)	<0.001
Number of hospital admission in 2012; mean (SD)	2.03 (2.00)	2.07 (3.03)	2.37 (2.34)	2.59 (2.50)	3.28 (2.97)	GOLD 1 vs 4, p=0.005; GOLD 2 vs 4 & 3 vs 4, p<0.001	2.70 (2.65)	1.86 (1.77)	<0.001	2.32 (2.46)	2.87 (2.72)	<0.001

Notes: GOLD 1–2 = GOLD 1 + GOLD 2; GOLD 3–4 = GOLD 3 + GOLD 4; GOLD 1–4 = GOLD 1 + GOLD 2 +GOLD 3 + GOLD 4. Bold figures indicate statistically significant (p<0.05).

Abbreviations: F, female; GOLD, Global Initiative for Chronic Obstructive Lung Disease; M, male.

Table 2 Use of health care resources of subjects according to the GOLD classification

	All subjects	GOLD 1	GOLD 2	GOLD 3	GOLD 4	p-value	GOLD 1–4	No lung function coding	p-value	GOLD 1–2	GOLD 3–4	p-value
Number	9,776	85	488	808	537		1,918	7,858		573	1,345
Number of A&E attendance/headcount; mean (SD)	3.8 (4.9)	5.8 (20.0)	4.1 (4.0)	4.2 (5.5)	4.4 (4.2)	NS	4.3 (6.3)	3.6 (4.4)	<0.001	4.3 (8.5)	4.3 (5.0)	0.944
Number of SOPC attendance/headcount; mean (SD)	2.5 (2.5)	2.4 (2.9)	2.8 (2.4)	3.1 (2.5)	3.2 (2.5)	GOLD 2 vs 4, p=0.031	3.0 (2.5)	2.3 (2.5)	<0.001	2.7 (2.5)	3.1 (2.5)	0.002
Number of hospital admissions/headcount; mean (SD)	2.0 (2.0)	2.1 (3.0)	2.4 (2.3)	2.6 (2.5)	3.3 (3.0)	GOLD 1 vs 4, p=0.005; GOLD 2 vs 4 & 3 vs 4, p<0.001	2.7 (2.7)	1.9 (1.8)	<0.001	2.3 (2.5)	2.9 (2.7)	<0.001
NIV support during acute admission; number (%)	2,278 (23.3)	17 (20)	146 (29.9)	291 (36.0)	309 (57.5)	<0.001	763 (39.8%)	1,515 (19.3%)	<0.001	163 (28.4%)	600 (44.6%)	<0.001
IMV support during acute admission number (%)	134 (1.4%)	2 (2.4)	7 (1.4)	13 (1.6)	15 (2.8)	0.211	37 (1.9%)	108 (1.4%)	0.072	9 (1.6%)	28 (2.1%)	0.456
Length of hospital stay/headcount in days; mean (SD)	12.3 (18.5)	9.72 (14.0)	13.74 (20.5)	17.46 (24.2)	23.49 (28.5)	GOLD 1 vs 3, 1 vs 4, 2 vs 4, 3 vs 4, p<0.001; GOLD 2 vs 3, p=0.017	17.9 (24.6)	11.00 (16.5)	<0.001	13.1 (19.7)	19.9 (26.2)	<0.001
COPD deaths in 2012; number (%)	503 (5.1%)	1 (1.2)	17 (3.5)	31 (3.8)	51 (9.5)	<0.001	100 (5.2)	403 (5.1)	0.88	18 (3.1)	82 (6.1)	0.008

Notes: GOLD 1–2 = GOLD 1 + GOLD 2; GOLD 3–4 = GOLD 3 + GOLD 4; GOLD 1–4 = GOLD 1 + GOLD 2 + GOLD 3 + GOLD 4. Bold figures indicate statistically significant (p<0.05).

Abbreviations: A&E, accident and emergency departments; GOLD, Global Initiative for Chronic Obstructive Lung Disease; IMV, invasive mechanical ventilation; NIV, noninvasive mechanical ventilation; NS, not significant; SOPC, specialist outpatient clinics.

Table 3 Medications use of subjects according to the GOLD classification

	All subjects (n=9,776)	GOLD 1 (n=85)	GOLD 2 (n=488)	GOLD 3 (n=808)	GOLD 4 (n=537)	p-value	GOLD 1–4 (n=1,918)	No lung function coding (n=7,858)	p-value	GOLD 1–2 (n=573)	GOLD 3–4 (n=1,345)	p-value
Not on LABA/LAMA/ICS	1,483 (15.2%)	16 (18.8%)	35 (7.2%)	20 (2.5%)	8 (1.5%)	<0.001	79 (4.1%)	1,404 (17.9%)	<0.001	51 (8.9%)	28 (2.1%)	<0.001
LABA alone	965 (9.9%)	8 (9.4%)	73 (15.0%)	102 (12.6%)	39 (7.3%)	0.002	222 (11.6%)	743 (9.5%)	0.005	81 (14.1%)	141 (10.5%)	0.022
LAMA alone	93 (1.0%)	1 (1.2%)	5 (1.0%)	10 (1.2%)	10 (1.9%)	0.276	26 (1.4%)	67 (0.9%)	0.042	6 (1.0%)	20 (1.5%)	0.446
ICS alone	3,285 (33.6%)	32 (37.6%)	130 (26.6%)	123 (15.2%)	27 (5.0%)	<0.001	312 (16.3%)	2,973 (37.8%)	<0.001	162 (28.3%)	150 (11.2%)	<0.001
LABA + LAMA	1,605 (16.4%)	8 (9.4%)	110 (22.5%)	260 (32.2%)	243 (45.3%)	<0.001	621 (32.4%)	984 (12.5%)	<0.001	118 (20.6%)	503 (37.4%)	<0.001
ICS + LABA (without LAMA)	988 (10.1%)	11 (12.9%)	57 (11.7%)	71 (8.8%)	34 (6.3%)	0.001	173 (9.0%)	815 (10.4%)	0.078	68 (11.9%)	105 (7.8%)	0.004
ICS + LAMA (without LABA)	329 (3.4%)	3 (3.5%)	28 (5.7%)	60 (7.4%)	27 (5.0%)	0.96	118 (6.2%)	211 (2.7%)	<0.001	31 (5.4%)	87 (6.5%)	0.377
ICS + LABA + LAMA	1,028 (10.5%)	6 (7.1%)	50 (10.2%)	162 (20.0%)	149 (27.7%)	<0.001	367 (19.1%)	661 (8.4%)	<0.001	56 (9.8%)	311 (23.1%)	<0.001

Notes: GOLD 1–2 = GOLD 1 + GOLD 2; GOLD 3–4 = GOLD 3 + GOLD 4; GOLD 1–4 = GOLD 1 + GOLD 2 + GOLD 3 + GOLD 4. Bold figures indicate statistically significant (p<0.05).

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting beta-agonists; LAMA, long-acting anti-muscarinic agent.

Table 4 Comorbidities of subjects according to the GOLD classification

Comorbidities	All subjects (n=9,776)	GOLD 1–4 (n=1,918)	No lung function coding (n=7,858)	p-value	GOLD 1–2 (n=573)	GOLD 3–4 (n=1,345)	p-value
Hypertension	3,932 (40.2%)	709 (37.0%)	3,223 (41.0%)	0.001	238 (41.5%)	471 (35.0%)	0.007
Ischemic heart disease	1,106 (11.3%)	240 (12.5%)	866 (11.0%)	0.064	74 (12.9%)	166 (12.3%)	0.729
Diabetes mellitus	1,469 (15.0%)	263 (13.7%)	1,206 (15.3%)	0.72	95 (16.6%)	168 (12.5%)	0.017
Chronic effect of TB	877 (9.0%)	239 (12.5%)	638 (8.1%)	<0.001	64 (11.2%)	175 (13.0%)	0.264
Bronchiectasis	738 (7.5%)	186 (9.7%)	552 (7.0%)	<0.001	46 (8.0%)	140 (10.4%)	0.107
Congestive heart failure	1,359 (13.9%)	200 (10.4%)	1,159 (14.7%)	<0.001	64 (11.2%)	136 (10.1%)	0.488
Asthma	342 (3.5%)	77 (4.0%)	265 (3.4%)	0.17	25 (4.4%)	52 (3.9%)	0.612

Notes: GOLD 1–2 = GOLD 1 + GOLD 2; GOLD 3–4 = GOLD 3 + GOLD 4; GOLD 1–4 = GOLD 1 + GOLD 2 + GOLD 3 + GOLD 4. Bold figures indicate statistically significant (p<0.05).

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; TB, tuberculosis.

Figure 1 Prevalence of comorbidities in COPD subjects according to GOLD classification (^#p=0.001; *p=0.048).

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; TB, tuberculosis.

Table 5 Cumulative mortality as on 31 December 2014 in the different groups of patients

Principal diagnosis on last discharge with mortality	All subjects (n=9,776)	GOLD 1 (n=85)	GOLD 2 (n=488)	GOLD 3 (n=808)	GOLD 4 (n=537)	No lung function coding (n=7,858)
Pneumonia	1,250 (32.3%)	8 (34.8%)	45 (28.1%)	76 (27.0%)	47 (19.3%)	1,074 (34.0%)
COPD	1,164 (30.1%)	3 (13%)	40 (25.0%)	92 (32.7%)	111 (45.7%)	918 (29.1%)
Lung cancer	243 (6.3%)	3 (13%)	18 (11.3%)	24 (8.5%)	8 (3.3%)	190 (6.0%)
Other malignancies	156 (4.0%)	0 (0%)	7 (4.4%)	6 (2.1%)	9 (3.7%)	134 (4.2%)
Respiratory failure	151 (3.9%)	0 (0%)	1 (0.6%)	20 (7.1%)	16 (6.6%)	115 (3.6%)
Ischemic heart disease	104 (2.7%)	0 (0%)	4 (2.5%)	8 (2.8%)	4 (1.6%)	88 (2.8%)
Sepsis and other systemic infections	102 (2.6%)	1 (4.3%)	8 (5.0%)	6 (2.1%)	4 (1.6%)	83 (2.6%)
Heart failure	71 (1.8%)	1 (4.3%)	5 (3.1%)	6 (2.1%)	4 (1.6%)	55 (1.7%)
Renal failure	40 (1.0%)	0 (0%)	1 (0.6%)	3 (1.1%)	2 (0.8%)	34 (1.1%)
Cerebrovascular accident	37 (1.0%)	0 (0%)	0 (0%)	4 (1.4%)	2 (0.8%)	31 (1.0%)
Others	549 (14.3%)	7 (30.4%)	31 (19.4%)	36 (12.1%)	36 (15.0%)	439 (13.9%)
All-cause mortality in HA hospital (%)	3,867/9,776 (39.6%)	23/85 (27.1%)	160/488 (32.8%)	281/808 (34.8%)	243/537 (45.3%)	3,160/7,858 (40.2%)
Death outside HA hospital (%)	560/9,776 (5.7%)	4/85 (4.7%)	23/488 (4.7%)	40/808 (5.0%)	34/537 (6.3%)	459/7,858 (5.8%)
Total mortality – in and outside HA hospital (%)#	4,427/9,776 (45.3%)	27/85 (31.8%)	183/488 (37.5%)	321/808 (39.7%)	277/537 (51.6%)	3,619/7,858 (46.1%)
Age at death, years; mean (SD), M, F*, [actual number of M & F patients with death]	M – 80.5 (8.4) [3,637]; F – 86.4 (7.7) [790]	M – 83.3 (9.9) [24]; F – 89.0 (7.3) [3]	M – 80.9 (7.1) [157]; F – 84.4 (6.7) [26]	M – 78.5 (7.5) [299]; F – 83.6 (5.1) [22]	M – 75.4 (7.9) [243]; F – 81.0 (8.4) [34]	M – 81.1 (8.4) [2,914]; F – 86.8 (7.6) [705]

Notes:

# GOLD 1–2 vs GOLD 3–4, p=0.002; GOLD 1 vs GOLD 4, p=0.002; GOLD 2 vs GOLD 4, p<0.0001; GOLD 3 vs GOLD 4, p<0.0001. GOLD 1–4 vs no lung function, 42.1% vs 46.1%, p=0.002.

* M: GOLD 1 vs GOLD 4, p=0.005; GOLD 2 vs GOLD 3, p=0.005; GOLD 2 vs GOLD 4, p<0.0001; GOLD 3 vs GOLD 4, p<0.0001; GOLD 1–2 vs GOLD 3–4, p<0.0001; GOLD 1–4 vs no lung function coding, p<0.0001; F: GOLD 1–4, p=NS; GOLD 1–4 vs no lung function coding, p<0.0001. Bold figures indicate statistically significant (p<0.05).

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; HA, Hospital Authority; NS, not significant.

Table 6 Top 5 causes of in-hospital mortality in 2012 and at 1 year and 2 years of discharge from hospital

Mortality in and outside HA hospitals	Death within 2012		1 year after hospital discharge in 2012		2 years after hospital discharge in 2012
		Number (%)		Number (%)		Number (%)
Top 5 causes of mortality in HA hospital (number, % of total mortality, in and outside HA hospitals)	1. COPD	503 (31.7)	1. COPD	303 (25.8)	1. Pneumonia	401 (32.2)
	2. Pneumonia	456 (28.8)	2. Pneumonia	282 (24.0)	2. COPD	271 (21.8)
	3. Lung cancer	107 (6.8)	3. Lung cancer	66 (5.6)	3. Lung cancer	55 (4.4)
	4. Respiratory failure	69 (4.4)	4. Other malignancies	37 (3.1)	4. Other malignancies	53 (4.3)
	5. Other malignancies	48 (3.0)	5. Respiratory failure	31 (2.6)	5. Respiratory failure	38 (3.1)
Total mortality in HA hospital (number)	1,585		831		1,092
Death outside HA hospital (number)	0		344		153
Total mortality (in and outside HA hospital) (number)	1,585		1,175		1,245

Abbreviation: HA, Hospital Authority.