Association Between Rural Residence and In-Hospital and 30-Day Mortality Among Veterans Hospitalized with COPD Exacerbations

Figures & data

Table 1 Characteristics of Patients Admitted with a COPD Hospitalization by Residence Location

Variables	Urban (n=43,549)	Rural (n=18,673)	Isolated Rural (n=2,692)	P-value*
Age, Years, Mean±SD	70.4±9.7	71.0±9.0	71.7±9.2	<0.001
Male, n (%)	41,691 (95.7)	18,069 (96.8)	2,602 (96.7)	<0.001
Race, n (%)				<0.001
White	31,054 (71.3)	16,414 (87.9)	2,392 (88.9)
Black	9,469 (21.7)	986 (5.3)	85 (3.2)
Other	1,316 (3.0)	597 (3.2)	93 (3.5)
Missing	1,710 (3.9)	676 (3.6)	122 (4.5)
Area Deprivation Index, Percentile, Mean±SD	59.3±26.4	66.0±19.6	69.8±16.9	<0.001
Comorbidities, n (%)
Obstructive sleep apnea	16,318 (37.5)	6,905 (37.0)	957 (35.6)	0.090
Diabetes	9,023 (20.7)	4,201 (22.5)	588 (21.8)	<0.001
Congestive heart failure	7,947 (18.3)	3,461 (18.5)	524 (19.5)	0.23
Pneumonia	22,932 (52.7)	10,417 (55.8)	1,411 (52.4)	<0.001
Hypertension	5,399 (12.4)	2,410 (12.9)	335 (12.4)	0.21
Peripheral vascular disease	4,357 (10.0)	2,006 (10.7)	289 (10.7)	0.02
Cancer	4,854 (11.2)	2,028 (10.9)	287 (10.7)	0.47
Coronary artery disease	3,890 (8.9)	1,797 (9.6)	282 (10.5)	0.002
Chronic kidney disease	4,351 (10.0)	1,743 (9.3)	244 (9.1)	0.02
Stroke	556 (1.3)	206 (1.1)	34 (1.3)	0.19
Liver Disease	2,069 (4.8)	632 (3.4)	70 (2.6)	<0.001
Rheumatoid arthritis	541 (1.2)	264 (1.4)	70 (2.6)	<0.001
Ulcer	518 (1.2)	266 (1.4)	38 (1.4)	0.044
Acquired immunodeficiency syndrome	201 (0.5)	25 (0.1)	1 (0.0)	<0.001
Dementia	602 (1.4)	177 (1.0)	33 (1.2)	<0.001
Admission Source, n (%)				<0.001
Outpatient	39,756 (91.4)	16,533 (88.6)	2,409 (89.5)
Acute care hospital	1,688 (3.9)	1,304 (7.0)	174 (6.5)
Nursing Home	980 (2.3)	327 (1.8)	29 (1.1)
Unknown/Other Facility	1,125 (2.6)	509 (2.7)	80 (3.0)
Travel Time to VA Minutes, Median (IQI)
Primary Care Provider	12 (8–18)	29 (18–41)	43 (31–72)	<0.001
Hospital	16.3 (8.8–30.7)	55.4 (34.0–83.9)	85.8 (57.2–120.6)	<0.001
Hospital Location, n (%)				<0.001
Rural	364 (0.8)	2,322 (12.4)	448 (16.6)
Urban	43,185 (99.2)	16,351 (87.6)	2,244 (83.4)
COPD-case Volume, n (%)				<0.001
Low	7,400 (17.0)	3,879 (20.8)	861 (32.0)
High	36,149 (83.0)	14,794 (79.2)	1,831 (68.0)
Hospital Complexity, n (%)				<0.001
High resource	40,206 (92.3)	15,191 (81.4)	1,842 (68.4)
Medium resource	2,028 (4.7)	2,067 (11.1)	501 (18.6)
Low resource	1,315 (3.0)	1,415 (7.6)	349 (13.0)
Labs, Mean±SD
Hematocrit%	39.0±6.2	39.0±6.2	39.2±6.1	0.197
WBC, 10^9 cells per L	10.0±4.9	10.5±5.1	10.7±5.3	<0.001
Sodium, mmol/L	137.7±4.8	137.6±4.7	137.7±4.5	0.053
Blood Urea Nitrogen, mg/dL	22.6±19.9	23.3±19.3	23.1±18.6	0.001
Creatinine, mg/dL	1.3±1.1	1.2±1.0	1.2±0.9	<0.001
Mortality, n (%)	2,150 (4.9)	1,033 (5.5)	141 (5.2)	0.008
30-day Mortality, n (%)	3,604 (8.3)	1,841 (9.9)	247 (9.2)	<0.001

Notes: *ANOVA for continuous and chi-square for categorical variables; Low and high COPD-case volume hospitals were defined as hospitals with the annual rate of COPD admissions below and above the median.

Table 2 Unadjusted in-Hospital Mortality for Rural and Urban Residing Veterans Stratified by Hospital Rurality, Volume, Complexity, and Admission Source

		Urban (n=43,549)	Rural (n=18,673)	Isolated Rural (n=2,692)	P-value
Hospital Rurality
Rural Hospital	n=3,134	27 (7.4%)	135 (5.8%)	31 (6.9%)	0.38
Urban Hospital	n=61,780	2,123 (4.9%)	898 (5.5%)	110 (4.9%)	0.016
COPD Volume
Low	n=12,140	508 (6.9%)	289 (7.5%)	52 (6.0%)	0.27
High	n=52,774	1,642 (4.5%)	744 (5.0%)	89 (4.9%)	0.058
Hospital Complexity
1 (High)	n=57,329	1,818 (4.5%)	787 (5.2%)	94 (5.1%)	0.004
2 (Medium)	n=4,596	178 (8.8%)	136 (6.6%)	27 (5.4%)	0.005
3 (Low)	n=3,079	154 (11.7%)	110 (7.8%)	20 (5.7%)	<0.001
Admission source
Outpatient	n=58,698	1,024 (2.6%)	505 (3.1%)	70 (2.9%)	0.006
Acute Care Hospital	n=3,166	603 (35.7%)	289 (22.2%)	42 (24.1%)	<0.001
Nursing Home	n=1,336	79 (8.1%)	33 (10.1%)	3 (10.3%)	0.50
Unknown/Other Facility	n=1,714	444 (39.5%)	206 (40.5%)	26 (32.5%)	0.40
Race
White	n=49,860	1,666 (5.4%)	892 (5.4%)	130 (5.4%)	0.95
Black	n=10,504	278 (2.9%)	41 (4.2%)	3 (3.5%)	0.10
Other	n=2,006	60 (4.6%)	43 (7.2%)	4 (4.3%)	0.053
Missing	n=2,508	146 (8.5%)	57 (8.4%)	4 (3.3%)	0.12

Notes: Chi-square was used for comparisons between groups. Low and high COPD-case volume hospitals were defined as hospitals with the rate of COPD admissions during the study period being below and above the median.

Figure 1 Unadjusted in-hospital mortality by travel time to the nearest Veterans Health Administration primary care provider and hospital. In-hospital mortality between quartiles was compared by Cochran-Armitage Trend Test.

Abbreviations: PCP, primary care physician; Q1, first (shortest travel time) quartile; Q2, second quartile; Q3, third quartile; Q4, fourth (longest travel time) quartile.

Figure 2 Multivariable logistic regression model for in-hospital mortality. Odds ratio with 95% confidence intervals are shown (x-axis) on log scale with base of 2. Low COPD-case volume hospitals were defined as hospitals with the annual rate of COPD admissions below the median.

Figure 3 Multivariable logistic regression model for 30-day mortality. Odds ratio with 95% confidence intervals are shown (x-axis) on log scale with base of 2. Low COPD-case volume hospitals were defined as hospitals with the annual rate of COPD admissions below the median.