Exacerbations among chronic bronchitis patients treated with maintenance medications from a US managed care population: an administrative claims data analysis

Figures & data

Figure 1 Flow chart of patient attrition.

Note: *Medications include: inhaled corticosteroids, long-acting β₂-agonists, SABA, and SAMA.
Abbreviations: CB, chronic bronchitis; COPD, chronic obstructive pulmonary disease; ED, emergency department; INP, inpatient hospitalization; OV, physician office visit; SABA, short-acting β₂-agonist; SAMA, short-acting muscarinic antagonist.

Table 1 Patient characteristics during the baseline year

Characteristic	Patients (n = 17,382)
Gender, n (%)
Female	8801 (50.6%)
Age groups, n (%)
40–54 years	2632 (15.1%)
55–64 years	5431 (31.3%)
≥65 years	9319 (53.6%)
Age, mean ± SD	66.7 ± 11.4
US geographic region
Northeast	3707 (21.3%)
Midwest	5321 (30.6%)
South	5776 (33.2%)
West	2526 (14.5%)
Unknown	52 (0.3%)
Health plan type
PPO	11,035 (63.5%)
HMO	3852 (22.2%)
Other	2495 (14.4%)
Baseline comorbidities, n (%)
Acute bronchitis and bronchiolitis	3843 (22.1%)
Acute sinusitis	1660 (9.6%)
Acute upper respiratory infection	1386 (8.0%)
Allergic rhinitis	1290 (7.4%)
Chronic sinusitis	748 (4.3%)
Other respiratory infections	661 (3.8%)
Insomnia	528 (3.0%)
Acute laryngitis and tracheitis	106 (0.6%)
Cardiovascular disease	6936 (39.9%)
Ischemic heart disease	4578 (26.3%)
Congestive heart failure	2760 (15.9%)
Peripheral vascular disease	1894 (10.9%)
Stroke or transient ischemic attack	1495 (8.6%)
Myocardial infarction	871 (5.0%)
Rheumatologic disease, n (%)	390 (2.2%)
Diabetes mellitus, n (%)	3689 (21.2%)
Hypertension, n (%)	9732 (56.0%)
Anxiety, n (%)	1345 (7.7%)
Depression, n (%)	1301 (7.5%)
Malignancy, n (%)	1597 (9.2%)
Baseline DCI score*, mean ± SD	1.3 ± 1.7

Note:

* Calculation excluded chronic obstructive pulmonary disease.

Abbreviations: DCI, Deyo–Charlson Comorbidity Index; HMO, health maintenance organization; PPO, preferred provider organization; SD, standard deviation.

Figure 2 Distribution of study population by COPD medication class on index date among overall patients.

Abbreviations: COPD, chronic obstructive pulmonary disease; ICS, inhaled corticosteroid; LABA, long-acting β₂-agonist; LAMA, long-acting muscarinic antagonist; SABA, short-acting β₂-agonist; SAMA, short-acting muscarinic antagonist.

Figure 3 Mean ± SD number of fills for COPD medications (maintenance and rescue) during the follow-up year among overall patients.

Abbreviations: COPD, chronic obstructive pulmonary disease; ICS, inhaled corticosteroid; LABA, long-acting β₂-agonist; LAMA, long-acting muscarinic antagonist; SABA, short-acting β₂-agonist; SAMA, short-acting muscarinic antagonist; SD, standard deviation.

Table 2 Annual exacerbation numbers and total costs during the follow-up year*

	Overall sample (n = 17,382)	Patients with at least two exacerbations during the baseline year (n = 1392)
Number of exacerbations
Moderate exacerbations
Patients with at least one exacerbation (%)	4287 (24.7%)	614 (44.1%)
Exacerbations among patients with at least one exacerbation, mean ± SD	1.4 ± 0.8	1.7 ± 1.0
Exacerbations among all patients, mean ± SD	0.3 ± 0.7	0.8 ± 1.1
Severe exacerbations
Patients with at least one exacerbation (%)	4290 (24.7%)	612 (44.0%)
Exacerbations among patients with at least one exacerbation, mean ± SD	1.4 ± 0.9	1.80 ± 1.31
Exacerbations among all patients, mean ± SD	0.4 ± 0.8	0.8 ± 1.3
Any exacerbation (at least one exacerbation)
Patients with at least one exacerbation	7402 (42.6%)	967 (69.5%)
Exacerbations among patients with at least one exacerbation, mean ± SD	1.6 ± 1.0	2.2 ± 1.5
Exacerbations among all patients, mean ± SD	0.7 ± 1.1	1.6 ± 1.6
Any exacerbation (at least two exacerbations)
Patients with at least two exacerbations (%)	2849 (16.4%)	572 (41.1%)
Exacerbations among patients with at least two exacerbations, mean ± SD	2.6 ± 1.1	3.1 ± 1.4
Exacerbation costs
Moderate exacerbations
Patients with at least one exacerbation, mean ± SD	$405 ± $1169	$518 ± $1525
All patients, mean ± SD	$124 ± $640	$277 ± $1096
Severe exacerbations
Patients with at least one exacerbation, mean ± SD	$25,364 ± $43,493	$29,948 ± $44,601
All patients, mean ± SD	$6260 ± $24,215	$13,096 ± $33,054
Any exacerbation
Patients with at least one exacerbation, mean ± SD	$14,991 ± $35,437	$19,251 ± $38,525
All patients, mean ± SD	$6384 ± $24,283	$13,373 ± $33,307

Notes:

* Costs in mid-2011 US dollars, adjusted for inflation using the medical care component of the Consumer Price Index in the 12-month follow-up period.

Abbreviation: SD, standard deviation.

Figure 4 Exacerbations during the follow-up year among overall patients.

Note: Any exacerbation = either moderate or severe exacerbation.

Table 3 Poisson regression results for the number of exacerbations (any type) during the follow-up year (n = 17,382)*

Covariates	RR	SE	95% Cl	P-value
Intercept	0.4121	0.0240	0.3676–0.4620	<0.0001
US geographic region
Midwest	1.1472	0.0260	1.0974–1.1993	<0.0001
Northeast	0.9710	0.0266	0.9203–1.0245	0.2817
West	0.8250	0.0273	0.7732–0.8803	<0.0001
South (reference)
Health plan type
HMO	1.0001	0.0230	0.9561–1.0462	0.9961
Other	1.0138	0.0313	0.9543–1.0771	0.6564
PPO (reference)
Gender
Female	1.0188	0.0187	0.9828–1.0561	0.3098
Male (reference)
Age	1.0035	0.0009	1.0017–1.0052	<0.0001
DCI score	1.0402	0.0053	1.0298–1.0507	<0.0001
Fills for COPD maintenance medications
LAMA	0.9956	0.0023	0.9912–1.0001	0.0561
Fixed-dose ICS + LABA inhaler	0.9864	0.0025	0.9815–0.9914	<0.0001
LABA	0.9953	0.0051	0.9853–1.0053	0.3526
ICS	0.9726	0.0044	0.9639–0.9813	<0.0001
Fills for COPD rescue medications during the follow-up year
SABA	1.0354	0.0019	1.0316–1.0392	<0.0001
SAMA	1.0248	0.0020	1.0208–1.0288	<0.0001
Number of exacerbations during baseline year	1.2963	0.0087	1.2794–1.3134	<0.0001

Note:

* Poisson distribution with log–link function.

Abbreviations: COPD, chronic obstructive pulmonary disease; DCI, Deyo–Charlson Comorbidity Index; HMO, health maintenance organization; ICS, inhaled corticosteroid; LABA, long-acting β₂-agonist; LAMA, long-acting muscarinic antagonist; PPO, preferred provider organization; SABA, short-acting β₂-agonist; SAMA, short-acting muscarinic antagonist; CI, confidence interval; RR, rate ratio; SE, standard error.

Figure 5 Mean ± SD cost per exacerbation during the follow-up year among overall patients.

Notes: Costs are in mid-2011 US dollars, adjusted for inflation using the medical care component of the Consumer Price Index; any exacerbation included either moderate or severe exacerbation.
Abbreviation: SD, standard deviation.

Table 4 Generalized linear model regression results for the cost of exacerbations (any type) during the follow-up year (n = 17,382)*

Covariates	RR	SE	95% CI	P-value
Intercept	9576.28	1474.23	7082.02–12,949.00	<0.0001
US geographic region
Midwest	0.8969	0.0522	0.8002–1.0053	0.0617
Northeast	0.8584	0.0603	0.7480–0.9851	0.0298
West	0.9121	0.0747	0.7769–1.0708	0.2610
South (reference)
Health plan type
HMO	0.9857	0.0588	0.8769–1.1081	0.8096
Other	1.3216	0.1060	1.1293–1.5465	0.0005
PPO (reference)
Gender
Female	0.9703	0.0458	0.8845–1.0643	0.5223
Male (reference)
Age	1.0041	0.0023	0.9996–1.0087	0.0756
DCI	1.1555	0.0168	1.1231–1.1889	<0.0001
Fills for COPD maintenance medications during the follow-up year
LAMA	0.9934	0.0067	0.9805–1.0066	0.3275
Fixed-dose ICS + LABA inhaler	0.9827	0.0075	0.9681–0.9975	0.0221
LABA	0.9773	0.0137	0.9507–1.0046	0.1023
ICS	0.9790	0.0133	0.9533–1.0054	0.1176
Fills for COPD rescue medications during the follow-up year
SABA	0.9948	0.0058	0.9836–1.0062	0.3715
SAMA	1.0214	0.0071	1.0076–1.0354	0.0023
Number of exacerbations during baseline year	1.0908	0.0252	1.0425–1.1415	0.0002

Note:

* Gamma distribution with log–link function.

Abbreviations: COPD, chronic obstructive pulmonary disease; DCI, Deyo–Charlson Comorbidity Index; HMO, health maintenance organization; ICS, inhaled corticosteroid; LABA, long-acting β_2-agonist; LAMA, long-acting muscarinic antagonist; PPO, preferred provider organization; SABA, short-acting β₂-agonist; SAMA, short-acting muscarinic antagonist; CI, confidence interval; RR, rate ratio; SE, standard error.