Clinical and Economic Burden of COPD in a Medicaid Population

Figures & data

Table 1.  Baseline description of study sample: after matching

Characteristics	COPD		Non-COPD
	(N = 10,221)		(N = 30,663)		p-valuea
Demographics
Age (mean, SD)	64.7	(12.9)	64.7	(12.9)	N/A^b
Male (n,%)	3766	(36.9%)	11,298	(36.9%)	N/A^b
Race (n,%)					N/A^b
Whiter	8159r	(79.8%)r	24,477r	(79.8%)r
Blackr	1507r	(14.7%)r	4521r	(14.7%)r
Hispanicr	84r	(0.8%)r	252r	(0.8%)r
Otherr	471r	(4.6%)r	1413r	(4.6%)r
Index year (n,%)r					N/A^b
2004r	5075r	(49.7%)r	15,225r	(49.7%)r
2005r	3935r	(38.5%)r	11,805r	(38.5%)r
2006r	1211r	(11.9%)r	3633r	(11.9%)r
Medicare/Medicaid dual-eligible (n,%)r	6625r	(64.8%)r	19,875r	(64.8%)r	N/A^b
Long-term care use (n,%)r	1538r	(15.1%)r	4579r	(14.9%)r	N/A^b
Overall disease burden in pre-indexr
Number of unique diagnosis (mean, SD)r	18.9r	(10.5)r	9.7r	(7.8)r	<0.001r
Number of unique prescription classes (mean, SD)r	13.9r	(8.0)r	9.0r	(7.1)r	<0.001r
Number of prescriptions (mean, SD)r	15.7r	(9.7)r	9.9r	(8.3)r	<0.001r
Presence of asthma (n,%)r	1666r	(16.3%)r	914r	(3.0%)r	<0.001r
Presence of depression (n,%)r	2855r	(27.9%)r	5346r	(17.4%)r	<0.001r
Presence of URTI (n,%)r	2374r	(23.2%)r	4081r	(13.3%)r	<0.001r
Presence of LRTI (n,%)r	4147r	(40.6%)r	2645r	(8.6%)r	<0.001r
Presence of CVD (n,%)r	6558r	(64.2%)r	11,824r	(38.6%)r	<0.001r
Presence of any cancer (n,%)r	1867r	(18.3%)r	4147r	(13.5%)r	<0.001r
CCIc (mean, SD)r	2.0r	(1.8)r	1.1r	(1.5)r	<0.001r
Individual CCI co-morbiditiesr
MI (n,%)r	660r	(6.5%)r	489r	(1.6%)r	<0.001r
CHF (n,%)r	3321r	(32.5%)r	2822r	(9.2%)r	<0.001r
Peripheral vascular disease (n,%)r	1613r	(15.8%)r	2077r	(6.8%)r	<0.001r
Cerebrovascular disease (n,%)r	1752r	(17.1%)r	3030r	(9.9%)r	<0.001r
Dementia (n,%)r	803r	(7.9%)r	2061r	(6.7%)r	<0.001r
Respiratory diagnosisc (n,%)r	2810r	(27.5%)r	1768r	(5.8%)r	<0.001r
Connective tissue disease (n,%)r	391r	(3.8%)r	729r	(2.4%)r	<0.001r
Peptic ulcer disease (n,%)r	299r	(2.9%)r	408r	(1.3%)r	<0.001r
Mild liver disease (n,%)r	205r	(2.0%)r	330r	(1.1%)r	<0.001r
Diabetes (n,%)r	3419r	(33.5%)r	7816r	(25.5%)r	<0.001r
Plegia (n,%)r	245r	(2.4%)r	571r	(1.9%)r	<0.001r
Renal (n,%)r	549r	(5.4%)r	907r	(3.0%)r	<0.001r
Malignant cancer tumors (n,%)r	674r	(6.6%)r	1682r	(5.5%)r	<0.001r
Diabetes complications (n,%)r	1144r	(11.2%)r	2339r	(7.6%)r	<0.001r
Moderate/severe liver disease (n,%)r	48r	(0.5%)r	69r	(0.2%)r	<0.001r
Metastatic tumors (n,%)r	70r	(0.7%)r	186r	(0.6%)r	0.228r
AIDS (n,%)r	37r	(0.4%)r	174r	(0.6%)r	0.001r

Key: AIDS –acquired immunodeficiency syndrome; CCI –Charlson comorbidity index; CHF –congestive heart failure; COPD –chronic obstructive pulmonary disease; CVD –cardiovascular disease; DME –durable medical equipment; ED –emergency department; OCS –oral corticosteroids; ICU –intensive care unit; LRTI –lower respiratory tract infection; MI –myocardial infarction; SABA –short-acting beta agonists; SD –standard deviation; URTI –upper respiratory tract infection.

^ap-values < 0.05 are bolded. p-values obtained from t-test for continuous variables and chi-square test for categorical variables.

^bN/A –not applicable. These variables were used for matching. cExcludes codes used for COPD.

Table 2.  Average annual, adjusted incremental cost for Medicaid beneficiaries attributable to COPD

All-cause Costr	COPD Mean^a (95% CI)r	Non-COPD Mean^a (95% CI)r	Incremental Cost^b	P-value^c
Totalr	$17,862 (16,643, 19,205)r	$15,744 (15,098, 16,448)r	$2118r	<0.001r
Pharmacyr	$5022 (5017, 5026)r	$3845 (3843, 3847)r	$1176r	<0.001r
Long-term carer	$5537 (4751, 6505)r	$6088 (5588, 6686)r	($551)r	0.006r
Medicalr	$7399 (7394, 7404)r	$5759 (5757, 5762)r	$1640r	<0.001r

Key: COPD –chronic obstructive pulmonary disease; CI –confidence interval.

^aMean represents predicted costs obtained from generalized linear model with log-link and appropriate distribution controlling for malignant cancer with or without metastasis, diabetes with and without complications, liver disease (mild, moderate, severe), connective tissue disease, peptic ulcer disease, hemiplegia or paraplegia, renal disease, and AIDS.

^bIncremental cost = (COPD cost) –(non-COPD cost).

^cp-values < 0.05 are bolded.

Figure 1.  (a) Stratified analyses: Incremental all-cause annual costs per Medicaid recipient for COPD –Medicare/Medicaid dual eligibility status. (b) Stratified analyses: Incremental all-cause annual costs per Medicaid recipient for COPD –race.

Figure 2.  All-cause adjusted healthcare resource use. COPD –chronic obstructive pulmonary disease; DME –durable medical equipment; ED –emergency department; IP –inpatient hospitalization; HH –home health; LTC –long-term care; OP –outpatient visit; Phy –physician visit. aPredicted proportions obtained from conditional logistic regression models controlling for malignant cancer with or without metastasis, diabetes with and without complications, liver disease (mild, moderate, severe), connective tissue disease, peptic ulcer disease, hemiplegia or paraplegia, renal disease, and AIDS. *Differences between COPD and non-COPD patients are statistically significant at p < 0.05.

Table 3.  All-cause adjusted healthcare resource use for Medicaid beneficiaries: Stratified by Medicare/Medicaid dual eligibility status and race

All-cause resource use componentr	COPD (%)^a	Non-COPD (%)^a	p-value^b
Non-dual-eligibler	(N = 3596)r	(N = 10,788)r
Inpatient hospitalizationr	31.7%r	15.0%r	<0.001r
EDr	51.4%r	33.1%r	<0.001r
Physician visitr	78.2%r	71.7%r	<0.001r
Outpatient visitr	82.8%r	75.6%r	<0.001r
Home health visit/DMEr	49.5%r	27.9%r	<0.001r
Long-term carer	21.3%r	18.6%r	<0.001r
Dual-eligibler	(N = 6625)r	(N = 19,875)r
Inpatient hospitalizationr	19.2%r	10.0%r	<0.001r
EDr	48.8%r	29.7%r	<0.001r
Physician visitr	82.3%r	75.9%r	<0.001r
Outpatient visitr	83.2%r	74.8%r	<0.001r
Home health visit/DMEr	62.1%r	33.5%r	<0.001r
Long-term carer	16.0%r	15.1%r	<0.001r
Whiter	(N = 8159)r	(N = 24,477)r
Inpatient hospitalizationr	22.0%r	10.9%r	<0.001r
EDr	49.4%r	30.0%r	<0.001r
Physician visitr	79.7%r	73.1%r	<0.001r
Outpatient visitr	83.0%r	75.2%r	<0.001r
Home health visit/DMEr	57.3%r	31.8%r	<0.001r
Long-term carer	18.8%r	17.3%r	<0.001r
Blackr	(N = 1507)r	(N = 4521)r
Inpatient hospitalizationr	30.8%r	16.4%r	<0.001r
EDr	51.1%r	35.0%r	<0.001r
Physician visitr	82.0%r	76.1%r	<0.001r
Outpatient visitr	81.2%r	72.4%r	<0.001r
Home health visit/DMEr	56.6%r	30.4%r	<0.001r
Long-term carer	17.9%r	16.2%r	<0.001r
Other (Hispanic/all other)r	(N = 555)r	(N = 1665)r
Inpatient hospitalizationr	28.6%r	12.0%r	<0.001r
EDr	52.2%r	31.9%r	<0.001r
Physician visitr	94.8%r	90.2%r	<0.001r
Outpatient visitr	90.4%r	82.6%r	<0.001r
Home health visit/DMEr	63.9%r	30.4%r	<0.001r
Long-term carer	3.1%r	2.2%r	0.140r

Key: CI –confidence interval; COPD –chronic obstructive pulmonary disease; DME –durable medical equipment; ED –emergency department.

^aPredicted proportions obtained from conditional logistic regression models controlling for malignant cancer with or without metastasis, diabetes with and without complications, liver disease (mild, moderate, severe), connective tissue disease, peptic ulcer disease, hemiplegia or paraplegia, renal disease, and AIDS.

^bp-values < 0.05 are bolded.

Table

Key: COPD –chronic obstructive pulmonary disease.

aIncludes patients meeting all study criteria.

bEligible index date: Patients with 12 months pre-index period and 12 months follow-up period eligibility as of index date.

cMatch variables: age (exact), gender, race, index year, Medicare dual eligibility, long-term care use during the 1-year pre-index period. Patients are unique and once matched are removed from the sample with no replacement.

Table

All-cause resource use componentr	COPD Meana (95% CI)r	Non-COPD Meana (95% CI)r	Incidence Rate Ratiob Estimate (95% CI)r	p-valuecr
Inpatient hospitalizationr	0.38 (0.36, 0.40)r	0.16 (0.15, 0.16)r	2.42 (2.29, 2.57)r	<0.001r
EDr	1.50 (1.44, 1.56)r	0.65 (0.63, 0.67)r	2.31 (2.19, 2.42)r	<0.001r
Physician visitr	7.93 (7.78, 8.10)r	5.21 (5.14, 5.29)r	1.52 (1.49, 1.56)r	<0.001r
Outpatient visitr	13.33 (12.80, 13.89)r	16.32 (15.75, 16.92)r	0.82 (0.78, 0.86)r	<0.001r
Home health visit/DMEr	26.88 (25.73, 28.08)r	12.27 (11.77, 12.79)r	2.19 (2.07, 2.32)r	<0.001r
Long-term carer	7.75 (7.36, 8.16)r	6.26 (5.98, 6.56)r	1.24 (1.19, 1.29)r	<0.001r

Key: CI –confidence interval; COPD –chronic obstructive pulmonary disease; DME –durable medical equipment; ED –emergency department.

aObtained from negative binomial model accounting for matched patients and controlling for malignant cancer with or without metastasis, diabetes with and without complications, liver disease (mild, moderate, severe), connective tissue disease, peptic ulcer disease, hemiplegia or paraplegia, renal disease, AIDS.

bIncidence rate ratio with non-COPD cohort as reference group.

cp-values < 0.05 are bolded. p-values correspond to significance of incidence rate ratio.