Risk of all-cause hospitalization in COPD patients initiating long-acting or short-acting beta agonist therapy

Figures & data

Figure 1. Patient selection. The number and percentage of patients excluded by each sample selection criteria.

Figure 2. Study design. Patients filled their first SABA or LABA prescription on the index data. Covariates were calculated during the baseline and treatment evaluation period. The outcome variables were assessed during the 6-month follow-up period.

Table 1. Patient characteristics during the baseline and treatment evaluation periods.

	SABA	LABA	p-value
	(n = 2134)	(n = 883)
Demographics
Age, mean (SD)	78.5 (8.2)	77.0 (7.2)	<0.001
Female, n (%)	1429 (67.0%)	570 (64.5%)	0.205
Race			<0.001
White, n (%)	1888 (88.5%)	791 (89.6%)
Black, n (%)	158 (7.4%)	43 (4.9%)
Hispanic, n (%)	42 (2%)	11 (1.25%)
Asian, n (%)	25 (1.2%)	21 (2.4%)
Native American, n (%)	12 (0.6%)	4 (0.5%)
Other, n (%)	8 (0.4%)	13 (1.5%)
Select comorbidities
Uncomplicated hypertension, n (%)	1764 (83.0%)	710 (80.4%)	0.145
Hyperlipidemia, n (%)	1220 (57.2%)	560 (63.0%)	0.002
Diabetes, n (%)	794 (37.2%)	264 (29.9%)	<0.001
Congestive heart failure, n (%)	786 (36.8%)	234 (26.5%)	<0.001
Anemia deficiency, n (%)	708 (33.2%)	225 (25.5%)	<0.001
Hypothyroidism, n (%)	546 (25.6%)	228 (25.8%)	0.891
Depression, n (%)	465 (21.8%)	124 (14.0%)	<0.001
Valvular disease, n (%)	417 (19.5%)	151 (17.0%)	0.256
Complicated hypertension, n (%)	347 (16.3%)	155 (17.5%)	0.390
CCI, mean (SD)	2.48 (2.35)	2.04 (2.34)	<0.0001
Health Service Use
Any spirometry, n (%)	83 (3.9%)	52 (5.9%)	0.028
Oral corticosteroid use, n (%)	401 (18.8%)	171 (19.4%)	0.280
Any specialist visit, n (%)	102 (4.8%)	93 (10.5%)	<0.001
Any physician visit, n (%)	1591 (74.6%)	820 (92.9%)	<0.001
Any ER visit, n (%)	497 (23.3%)	158 (17.9%)	<0.001
Any hospitalization, n (%)	809 (37.9%)	266 (30.1%)	<0.001
Length of stay, mean (SD)	11.01 (28.0)	5.39 (15.0)	<0.001

CCI, Charlson Comorbidity Index; ER, Emergency Room; LABA, Long-Acting Beta Agonist; SABA, Short-Acting Beta Agonist.

Figure 3. Kaplan-Meier curve for time to all-cause hospitalization. After correcting for background characteristics, the LABA treated patients had a significantly lower risk of hospitalization (HR = 0.74, p = 0.002).

Table 2. Results of Cox proportional hazards model for time to hospitalization.

Variable	HR	95% CI	p-value
LABA use	0.744	0.616–0.900	0.002
Age	0.996	0.985–1.006	0.396
Female	1.018	0.859–1.205	0.840
Race (vs White)
Black	1.146	0.862–1.522	0.348
Hispanic	0.804	0.453–1.430	0.458
Asian	0.645	0.288–1.446	0.287
Native American	1.740	0.648–4.672	0.272
Other	0.227	0.032–1.616	0.139
CCI	1.143	1.112–1.175	<0.001
Spirometry tests	1.207	1.114–1.309	<0.001
OCS use	1.001	0.997–1.005	0.681
Specialist visits	0.923	0.830–1.027	0.141
Physician visits	1.030	1.013–1.047	<0.001
Prior LOS	1.009	1.007–1.012	<0.001

HR, Hazard Ratio; CI, Confidence Interval; CCI, Charlson Comorbidity Index; LOS, Length of Stay; LABA, Long-Acting Beta Agonist.