Association between adherence to medications for COPD and medications for other chronic conditions in COPD patients

Figures & data

Table 1 GPI codes for maintenance COPD medications and non-COPD medications

Drug/drug class name	GPI code
mCOPD medications
Aclidinium	4410000710*
Tiotropium	4410008010*
Budesonide-formoterol	4420990241*
Fluticasone-salmeterol	4420990270*
Mometasone-formoterol	4420990290*
Non-COPD medications
Antianxiety	57*
Anticoagulants	8310*, 8320*, 8333*, 8337*
Antidepressants	58*
Antihyperglycemics	2715*, 2717*, 2720*, 2725*, 2728*, 2750*, 2755*, 2757*, 2760*, 2799*
Antihypertensives	36*
Beta-blockers	33*
Bisphosphonates	300420*
Calcium channel blockers	34*
Diuretics	37*
Insulin	2710*
NSAIDs	6610*
Statins	3940*

Note:

* All medications with the GPI prefix were included for identification.

Abbreviations: GPI, generic product identifier; mCOPD, maintenance COPD; NSAIDs, nonsteroidal anti-inflammatory drugs.

Figure 1 Patient selection.

Notes: ^aCOPD diagnosis: ≥2 medical claims occurring on separate dates within 90 days with a COPD diagnosis code (ICD-9-CM code 491.xx, 492.xx, or 496.xx) in the primary or secondary position. ^bIndex date: The date of first medical claim with a COPD diagnosis during the identification period. ^cPre-index period: A 12-month period prior to index date. ^dPost-index period: A 24-month period after index date. ^e≥1 medical claim with any of the following ICD-9-CM diagnosis codes in any position: 277.0x (cystic fibrosis), 011.x (pulmonary tuberculosis), or 140.xx-172.xx, 174.xx-209.3x, 209.7x (malignant neoplasms).
Abbreviations: ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; MAPD, Medicare Advantage plans with Prescription Drug benefits.

Table 2 Baseline patient characteristics: overall and by mCOPD medication adherence statusa

Baseline patient characteristic	Overall (n=14,117)	Adherent to mCOPD medications (n=2,940)	Non-adherent to mCOPD medications (n=11,177)	P-value
Age, years
Mean (SD)	69.9 (±9.2)	69.8 (±8.8)	70.0 (±9.3)	0.3402
Median (IQR)	70.0 (66.0–76.0)	70.0 (66.0–76.0)	70.0 (66.0–76.0)
Age category, n (%)
40–49 years	369 (2.6)	67 (2.3)	302 (2.7)	0.2008
50–59 years	1,471 (10.4)	305 (10.4)	1,166 (10.4)	0.9270
60–69 years	4,799 (34.0)	1,022 (34.8)	3,777 (33.8)	0.3235
70–79 years	5,324 (37.7)	1,135 (38.6)	4,189 (37.5)	0.2620
80–89 years	2,154 (15.3)	411 (14.0)	1,743 (15.6)	0.0303
Sex, n (%)
Female	8,348 (59.1)	1,769 (60.2)	6,579 (58.9)	0.1992
Male	5,769 (40.9)	1,171 (39.8)	4,598 (41.1)
Geographic location, n (%)
Northeast	254 (1.8)	76 (2.6)	178 (1.6)	0.0003
Midwest	3,481 (24.7)	858 (29.2)	2,623 (23.5)	<0.0001
South	9,285 (65.8)	1,740 (59.2)	7,545 (67.5)	<0.0001
West	1,097 (7.8)	266 (9.0)	831 (7.4)	0.0037
Line of business, n (%)
Medicare	13,512 (95.7)	2,789 (94.9)	10,723 (95.9)	0.0105
Commercial	605 (4.3)	151 (5.1)	454 (4.1)
RxRisk-V comorbidity scoreb
Mean (SD)	7.2 (±3.1)	7.0 (±3.1)	7.2 (±3.1)	0.0004
Median (IQR)	7.0 (5.0–9.0)	7.0 (5.0–9.0)	7.0 (5.0–9.0)
Influenza vaccination status, n (%)
Nullc	5,488 (38.9)	1,042 (35.4)	4,446 (39.8)	<0.0001
Partialc	4,434 (31.4)	957 (32.6)	3,477 (31.1)	0.1338
Fullc	4,195 (29.7)	941 (32.0)	3,254 (29.1)	0.0023

Notes:

a Measured during the 12-month pre-index period.

b RxRisk-V score without DME ranges from 0 to 42, with a higher score indicating a greater chronic disease burden.

c Influenza vaccination status was based on the number and timing of vaccine claims during the post-index period as follows: null =0; partial = ≥1; full = ≥2 claims occurring 6 months or greater apart.

Abbreviations: DME, durable medical equipment; IQR, interquartile range; SD, standard deviation; mCOPD, maintenance COPD.

Figure 2 Adherence measured as PDC for mCOPD and non-COPD medications.

Abbreviations: mCOPD, maintenance COPD; NSAIDs, nonsteroidal anti-inflammatory medications; PDC, proportion of days covered.

Table 3 Association between non-adherence to mCOPD medications and non-adherence to non-COPD medications: logistic regression analysisa

Variable	Odds ratio	Lower 95% CI	Upper 95% CI	P-value
Dependent variable
Non-adherence (PDC <0.8) to mCOPD medications	NA	NA	NA	NA
Main independent variables
Non-adherence (PDC <0.8) to
Statins	1.54	1.37	1.74	<0.0001
Antihypertensives	1.55	1.38	1.74	<0.0001
Anticoagulants	1.21	0.93	1.57	0.1497
Oral antihyperglycemics	1.38	1.13	1.69	0.0019
Insulins	1.78	1.28	2.47	0.0005
Antidepressants	1.73	1.50	1.99	<0.0001
NSAIDs	1.74	1.39	2.18	<0.0001
Antianxiety	1.16	0.93	1.45	0.1873
Calcium channel blockers	1.53	1.31	1.78	<0.0001
Beta-blockers	1.39	1.21	1.61	<0.0001
Bisphosphonates	1.51	1.20	1.91	0.0005
Diuretics	1.44	1.27	1.63	<0.0001

Notes:

a Study population, n=14,117. Baseline patient characteristics including age, sex, region, influenza vaccination status, and RxRisk-V score were included in the model as covariates.

Abbreviations: CI, confidence interval; mCOPD, maintenance COPD; NA, not applicable; NSAIDs, nonsteroidal anti-inflammatory drugs; PDC, proportion of days covered.