Factors Influencing the Length of Hospital Stay Among Patients with Chronic Obstructive Pulmonary Disease (COPD) in Macao Population: A Retrospective Study of Inpatient Health Record

Figures & data

Figure 1 Key steps of data analysis in this study.

Table 1 Demographic Information and Blood Test Results (n=1116)

Variables	n (%)
Gender
Male	743 (66.6%)
Female	373 (33.4%)
Age (years)
Median (IQR)	81.00 (72.00–87.00)
Mean (SD)	79.42 (10.35)
History of tobacco smoking
No	419 (37.5%)
Yes	195 (17.5%)
Quit	502 (45.0%)
Number of comorbidities
0	155 (13.9%)
1	297 (26.6%)
2	304 (27.2%)
3	247 (22.1%)
4 or more	113 (10.1%)
Blood eosinophil count (cells/uL)
Median (IQR)	129.03 (35.77–297.84)
Mean (SD)	217.03 (293.99)
Below 300 cells/uL	840 (75.3%)
Above 300 cells/uL	276 (24.7%)
Hemoglobin (g/L)
Median (IQR)	125.00 (112.00–138.00)
Mean (SD)	125.00 (20.32)
Below normal range	670 (60.0%)
Normal range	432 (38.8%)
Above normal range	14 (1.2%)
WBC (10^9/L)
Median (IQR)	8.80 (6.79–12.18)
Mean (SD)	10.02 (4.63)
Below normal range	19 (1.7%)
Normal range	160 (4.3%)
Above normal range	937 (94.0%)
Creatinine (μmol/L)
Median (IQR)	77.00 (63.00–95.00)
Mean (SD)	89.8 (58.9)
Below normal range (Male,Female)	46 (6.2%), 27 (7.2%)
Normal range (Male,Female)	562 (75.6%), 275 (73.7%)
Above normal range (Male,Female)	135 (18.2%), 71 (19.1%)

Table 2 Descriptive Analysis of Clinical Therapies and Length of Hospital Stay

Variables	n (%)
Systemic steroids
No	596 (53.4%)
Yes	520 (46.6%)
Antibiotics
No	288 (25.8%)
Yes	828 (74.2%)
Oxygen therapy
No	125 (11.2%)
Yes	991 (88.8%)
Noninvasive ventilation
No	988 (88.5%)
Yes	128 (11.5%)
Pulmonary rehabilitation
No	996 (89.2%)
Yes	120 (10.8%)
Inhaled medications*
Group 1	246 (22%)
Group 2	230 (20.6%)
Group 3	582 (52.2%)
Group 4	58 (5.2%)
Length of hospital stay
Median (IQR)	11.00 (6.00–16.00)
Mean (SD)	12.28 (9.23)

Notes: *Group 1 – patients who used one type of inhaled medications only “LABA, LAMA or both”, “SABA, SAMA or both” or ICS only. Group 2 – patients who used two types of inhaled medications “(LABA, LAMA or both) and (SABA, SAMA or both)”, “(LABA, LAMA or both) and ICS” or “(SABA, SAMA or both) and ICS”. Group 3 – the use of three types of inhaled medications “(LABA, LAMA or both) and (SABA, SAMA or both) and ICS”. Group 4 – patients who did not use any inhaled medications during hospitalization.

Table 3 Significant Factors Associated with LOS

	Univariate Analysis		Multivariable Regression Analysis
	B, t and F	P	B [95% CI]	P
Age	B =0.285	<0.001	0.178 [0.535–1.072]	<0.001
Gender	t=6.173	<0.001	−1.147 [−0.138–0.056]	<0.001
Tobacco smoking	F=22.145	<0.001
Yes	–	–	−0.086 [−0.124–0.018]	0.008
Quit	–	–	0.072 [0.004–0.087]	0.030
Number of comorbidities	F=6.559	<0.001
One	–	–	0.126 [0.034–0.147]	0.002
Two	–	–	0.125 [0.031–0.144]	0.002
Three	–	–	0.116 [0.028–0.146]	0.004
Four or more	–	–	0.090 [0.021–0.166]	0.011
Blood eosinophil count	B =−0.071	0.024	−0.041 [−0.056–0.008]	0.138
Hemoglobin	B =−0.212	<0.001	−0.118 [−0.629- −0.214]	<0.001
WBC	B =−0.034	0.260	–	–
Creatinine	B =0.003	0.929	–	–
Systemic steroids	t=−2.807	0.038	0.037 [−0.012–0.058]	0.193
Antibiotics	t=−1.604	0.109	–	–
Oxygen therapy	t=−0.179	<0.001	0.052 [−0.003–0.105]	0.063
Noninvasive ventilation	t=−7.668	<0.001	0.067 [0.009–0.124]	0.023
Pulmonary rehabilitation	t=−14.955	<0.001	0.232 [0.181–0.297]	<0.001
Inhaled medications	F=17.290	<0.001
Group 1			0.0447 [−0.044–0.116]	0.383
Group 2			0.109 [0.003–0.166]	0.043
Group 3			0.255 [0.083–0.237]	<0.001

Notes: B denotes the unstandardized beta in linear regression, which represents the slope of the line between the predictor variable and the dependent variable. F denotes the F value in ANOVA test, which was calculated by variance of the group means divided by mean of the within group variances; t denotes the t value in T-test, which measures the size of the difference relative to the variation in the sample data. Bold values denote statistical significance at the p < 0.05 level.