Hospital cost and length of stay in idiopathic pulmonary fibrosis

Figures & data

Table 1. Patient clinical characteristics and treatment among IPF patients admitted with a principal diagnosis of respiratory disease.

	Index year, Mean (SE)/n (%)				p-value
	Y2009 (n = 7,346)	Y2010 (n = 6,643)	Y2011 (n = 8,362)	All (n = 22,350)
No. of chronic conditions	4.2 (±0.05)	4.2 (±0.05)	4.5 (±0.05)	4.3 (±0.03)	<.001
Chronic obstructive pulmonary disease	2,978 (40.5%)	2,373 (35.7%)	3,184 (38.1%)	8,535 (38.2%)	.105
Asthma	646 (8.8%)	581 (8.7%)	694 (8.3%)	1,922 (8.6%)	.895
Bacterial pneumonia	2,876 (39.1%)	2,581 (38.9%)	3,147 (37.6%)	8,604 (38.5%)	.700
Lung cancer	99 (1.4%)	149 (2.2%)	159 (1.9%)	407 (1.8%)	.239
Mechanical ventilation	887 (12.1%)	764 (11.5%)	894 (10.7%)	2,546 (11.4%)	.578
Non-invasive ventilation	583 (7.9%)	550 (8.3%)	862 (10.3%)	1,995 (8.9%)	.112
Cardiovascular conditions	3,379 (46.0%)	2,929 (44.1%)	3,755 (44.9%)	10,063 (45.0%)	.635
Ischemic heart disease	2,202 (30.0%)	1,811 (27.3%)	2,327 (27.8%)	6,339 (28.4%)	.274
Myocardial infarction	486 (6.6%)	321 (4.8%)	539 (6.4%)	1,345 (6.0%)	.125
Congestive heart failure	2,109 (28.7%)	1,806 (27.2%)	2,304 (27.6%)	6,219 (27.8%)	.703
Pulmonary hypertension	30 (0.4%)	16 (0.2%)	38 (0.5%)	84 (0.4%)	.568
Principal diagnosis of IPF	3,043 (41.4%)	2,929 (44.1%)	3,653 (43.7%)	9,626 (43.1%)	.504
APR-DRG severity of illness
Minor loss of function	129 (1.8%)	116 (1.8%)	202 (2.4%)	447 (2.0%)	.457
Moderate loss of function	1,723 (23.5%)	1,549 (23.3%)	1,786 (21.4%)	5,058 (22.6%)
Major loss of function	3,448 (46.9%)	3,196 (48.1%)	3,895 (46.6%)	10,538 (47.1%)
Extreme loss of function	2,046 (27.9%)	1,782 (26.8%)	2,479 (29.6%)	6,307 (28.2%)

Table 2. Patient demographics, hospital characteristics, and admission type among IPF patients admitted with a principal diagnosis of respiratory disease.

	Index year, Mean (±SE)/n (%)				p-value
	Y2009 (n = 7,346)	Y2010 (n = 6,643)	Y2011 (n = 8,362)	All (n = 22,350)
Age	69.6 (±0.49)	69.6 (±0.51)	70.6 (±0.54)	70.0 (±0.32)	<.001
Female	3,687 (50.2%)	3,334 (50.2%)	3,955 (47.3%)	10,976 (49.1%)	.245
Race					.208
White	4,491 (61.1%)	4,373 (65.8%)	5,539 (66.2%)	14,404 (64.4%)
Black	503 (6.9%)	527 (7.9%)	677 (8.1%)	1,707 (7.6%)
Hispanic	714 (9.7%)	652 (9.8%)	745 (8.9%)	2,110 (9.4%)
Other	365 (5.0%)	385 (5.8%)	379 (4.5%)	1,128 (5.0%)
Missing	1,273 (17.3%)	706 (10.6%)	1,023 (12.2%)	3,002 (13.4%)
Primary payer type					.616
Medicare	5,016 (68.3%)	4,445 (66.9%)	5,836 (69.8%)	15,297 (68.4%)
Medicaid	578 (7.9%)	466 (7.0%)	486 (5.8%)	1,531 (6.9%)
Private (including HMO)	1,471 (20.0%)	1,415 (21.3%)	1,704 (20.4%)	4,590 (20.5%)
Self-pay	110 (1.5%)	163 (2.5%)	175 (2.1%)	448 (2.0%)
Missing/No charge/Other	171 (2.3%)	153 (2.3%)	161 (1.9%)	484 (2.2%)
Hospital region					.994
Northeast	1,232 (16.8%)	1,157 (17.4%)	1,509 (18.0%)	3,897 (17.4%)
Midwest	1,914 (26.0%)	1,628 (24.5%)	2,102 (25.1%)	5,644 (25.3%)
South	2,932 (39.9%)	2,744 (41.3%)	3,493 (41.8%)	9,169 (41.0%)
West	1,269 (17.3%)	1,114 (16.8%)	1,258 (15.0%)	3,641 (16.3%)
Teaching hospital	2,914 (39.7%)	2,870 (43.2%)	3,902 (46.7%)	9,687 (43.3%)	.342
Bed size					.632
Small	977 (13.3%)	801 (12.1%)	1,032 (12.3%)	2,811 (12.6%)
Medium	1,684 (22.9%)	1,227 (18.5%)	1,897 (22.7%)	4,807 (21.5%)
Large	4,551 (62.0%)	4,535 (68.3%)	5,361 (64.1%)	14,447 (64.6%)
Missing	134 (1.8%)	80 (1.2%)	72 (0.9%)	286 (1.3%)
Evidence of ED services^a	5,053 (68.8%)	4,399 (66.2%)	5,461 (65.3%)	14,912 (66.7%)	.374
Elective admission^b	1,189 (16.2%)	1,066 (16.0%)	1,258 (15.0%)	3,512 (15.7%)	.766

^a Defined by NIS as having either an ED revenue code, charge, CPT procedure code, or admission source, or being on a state-defined ED record.

^b Defined by NIS as admission other than emergency, urgent, newborn, delivery, trauma center, or other-non elective.

Table 3. Patient discharge status, length of stay, and total costs among IPF patients admitted with a principal diagnosis of respiratory disease.

	Index year, Mean (±SE)/n (%)				p-value
	Y2009 (n = 7,346)	Y2010 (n = 6,643)	Y2011 (n = 8,362)	All (n = 22,350)
Discharge status					.214
Routine	3,503 (47.7%)	3,133 (47.2%)	3,731 (44.6%)	10,367 (46.4%)
Transfer to short-term hospital	191 (2.6%)	176 (2.6%)	357 (4.3%)	724 (3.2%)
Transfer to other facilities	1,254 (17.1%)	1,096 (16.5%)	1,534 (18.3%)	3,883 (17.4%)
Home healthcare	1,274 (17.3%)	1,263 (19.0%)	1,582 (18.9%)	4,118 (18.4%)
Died in hospital	1,071 (14.6%)	947 (14.3%)	1,128 (13.5%)	3,146 (14.1%)
Other^a	54 (0.7%)	30 (0.4%)	29 (0.3%)	112 (0.5%)
Days of stay (among all IPF patients)	7.7 (±0.26)	7.4 (±0.31)	7.0 (±0.20)	7.4 (±0.15)	<.001
Died in hospital	1,071 (14.6%)	947 (14.3%)	1,128 (13.5%)	3,146 (14.1%)	.740
Total inpatient costs (2011 US$)	$16,275 (±833)	$16,779 (±1,200)	$15,254 (±898)	$16,042 (±631)	<.001
	Q1, Median, Q3
Days of stay (among all IPF patients)	3, 5, 9	3, 5, 9	3, 5, 9	3, 5, 9
Total inpatient costs (2011 US$)	$5,256, $8,925, $17,976	$5,741, $9,611, $18,525	$5,702, $9,580, $17,006	$5,557, $9,373, $17,811

^a Against medical advice, discharged alive, or destination unknown.

Table 4. Linear regression model for LOS and inpatient charges among IPF patients admitted with a principal diagnosis of respiratory disease.

Parameter	Linear regression models
	Length of stay (days)		Total inpatient costs (2011 US$)
	Estimates (95% CI)	p-value	Estimates (95% CI)	p-value
Age, per year	−0.04 (−0.06– −0.02)	<.001	−$148 (−215– −81)	<.001
Female vs Male	0.07 (−0.40–0.55)	.759	−$37 (−1,361–1,287)	.956
Race
White vs Other	0.54 (−0.59–1.67)	.346	−$2,093 (−5,714–1,528)	.257
Black vs Other	0.75 (−0.53–2.04)	.252	−$349 (−3,660–2,961)	.836
Hispanic vs Other	0.08 (−1.09–1.25)	.897	−$1,152 (−4,563–2,259)	.508
Missing vs Other	0.46 (−0.82–1.73)	.480	−$837 (−4,211–2,538)	.627
Primary diagnosis of IPF	0.30 (−0.15–0.76)	.189	$2,099 (1,042–3,155)	<.001
Lung cancer	0.83 (−1.46–3.11)	.478	$4,431 (−2,641–11,503)	.219
Selected cardiovascular conditions^a	0.36 (−0.11–0.82)	.131	$20 (−1,443–1,483)	.979
Bacterial pneumonia	1.18 (0.69–1.68)	<.001	$2,978 (1,595–4,362)	<.001
Non-invasive ventilation	2.03 (0.94–3.12)	<.001	$5,500 (2,373–8,628)	<.001
Mechanical ventilation	9.82 (8.42–11.23)	<.001	$36,911 (32,253–41,568)	<.001

CI, confidence interval.

^a Ischemic heart disease, myocardial infarction, and congestive heart failure.