Metformin use and health care utilization in patients with coexisting chronic obstructive pulmonary disease and diabetes mellitus

Figures & data

Figure 1 Establishment of the cohort.

Abbreviations: COPD, chronic obstructive pulmonary disease; ESRD, end-stage renal disease.

Table 1 Baseline characteristics of patients with coexisting COPD and DM during 2007–2010 by metformin use

Patient characteristics	Metformin use		p-valuec
	Yesa (n=3,193)	Nob (n=8,067)
Age (years)			<0.0001
66–74	1,501 (47.01)	2,737 (33.93)
75–84	1,400 (43.85)	3,958 (49.06)
85+	292 (9.15)	1,372 (17.01)
Gender			0.16
Male	1,042 (32.63)	2,522 (31.26)
Female	2,151 (67.37)	5,545 (68.74)
Race/ethnicity			<0.0001
White	2,513 (78.70)	5,775 (71.59)
Non-white	680 (21.30)	2,292 (28.41)
Dual eligibility	1,268 (39.71)	4,408 (54.64)	<0.0001
Hospitalizations, prior year			<0.0001
0	2,474 (77.48)	5,509 (68.29)
1	506 (15.85)	1,592 (19.73)
2+	213 (6.67)	966 (11.97)
COPD complexity			0.036
Low	2,354 (73.72)	5,757 (71.36)
Moderate	704 (22.05)	1,958 (24.27)
High	135 (4.23)	352 (4.36)
Complications of DM	472 (14.78)	2,697 (33.43)	<0.0001
Uncontrolled DM	672 (21.05)	2,802 (34.73)	<0.0001
Oxygen use, prior year	371 (11.62)	1,180 (14.63)	<0.0001
Spirometry, prior year and following 2 years	960 (30.07)	2,319 (28.75)	0.17
Comorbidities
GERD, prior year	382 (11.96)	987 (12.24)	0.69
Anxiety/depression, prior year	261 (8.17)	639 (7.92)	0.66
CVD, prior year	1,335 (41.81)	4,011 (49.72)	<0.0001
Sarcopenia, prior year	4 (0.13)	8 (0.10)	0.70
Osteoporosis, prior year	149 (4.67)	384 (4.76)	0.83
COPD medication, 2-year follow-up			0.0001
Long-acting medication only	378 (11.84)	834 (10.34)
Short-acting medication only	427 (13.37)	1,329 (16.47)
Both	625 (19.57)	1,598 (19.81)
None	1,763 (55.21)	4,306 (53.38)

Notes:

a Those who had coexisting COPD and DM and received prescription for metformin during 2007–2010.

b Those who had coexisting COPD and DM and received antidiabetics prescription other than metformin, such as insulin, sulfonylurea, acarbose, exenatide, glucagon, miglitol, nateglinide, pioglitazone, pramlintide, repaglinide, rosiglitazone, saxagliptin, or sitagliptin during 2007–2010.

c χ² test and Fisher’s exact test for sarcopenia. Data presented as n (%) unless otherwise indicated.

Abbreviations: COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; DM, diabetes mellitus; GERD, gastroesophageal reflux disease.

Table 2 ER visits and hospitalizations over a 2-year follow-up period in patients with coexisting COPD and DM

ER visits and hospitalizations	Metformin users		p-valuec
	Yesa n (%)	Nob n (%)
COPD-specific (overall)	227 (7.11)	775 (9.61)	<0.0001
COPD complexity
Low	97 (4.12)	350 (6.08)	0.0004
Moderate	108 (15.34)	370 (18.90)	0.035
High	22 (16.30)	55 (15.63)	0.86
All-cause (overall)	1,968 (61.63)	5,749 (71.27)	<0.0001
COPD complexity
Low	1,370 (58.20)	3,887 (67.52)	<0.0001
Moderate	496 (70.45)	1,578 (80.59)	<0.0001
High	102 (75.56)	284 (80.68)	0.21

Notes:

a Those who had coexisting COPD and DM and received prescription for metformin during 2007–2010.

b Those who had coexisting COPD and DM and received antidiabetics prescription other than metformin, such as insulin, sulfonylurea, acarbose, exenatide, glucagon, miglitol, nateglinide, pioglitazone, pramlintide, repaglinide, rosiglitazone, saxagliptin, or sitagliptin during 2007–2010.

c χ² test.

Abbreviations: COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus; ER, emergency room.

Table 3 Odds of ER visits and hospitalizations in patients with coexisting COPD and DM after the initial antidiabetic prescription during 2007–2010

Antidiabetic use	ER visits or hospitalizations odds ratio (95% confidence interval)a
	COPD-specific		All-cause
	COPD complexity		COPD complexity
	Low	Moderate/high	Low	Moderate/high
Metformin use
Nob	Reference	Reference	Reference	Reference
Yesc	0.66 (0.52–0.85)	0.82 (0.64–1.04)	0.73 (0.65–0.81)	0.72 (0.59–0.88)

Notes:

a Multivariable logistic regression model was used to estimate odds ratio, adjusted by age, gender, race, dual eligibility, prior-year hospitalization, DM complexity, comorbidities (GERD, anxiety and depression, CVD, sarcopenia, and osteoporosis), prior-year oxygen use, and COPD maintenance medications use.

b Those who had coexisting COPD and DM and received antidiabetics prescription other than metformin, such as insulin, sulfonylurea, acarbose, exenatide, glucagon, miglitol, nateglinide, pioglitazone, pramlintide, repaglinide, rosiglitazone, saxagliptin, or sitagliptin during 2007–2010.

c Those who had coexisting COPD and DM and received prescription for metformin during 2007–2010.

Abbreviations: COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; DM, diabetes mellitus; ER, emergency room; GERD, gastroesophageal reflux disease.

Table 4 Odds of ER visits/hospitalizations in patients with coexisting COPD and DM after the index antidiabetic prescription during 2007–2010

Antidiabetics	ER visits or hospitalizations odds ratio (95% confidence interval)a
	COPD-specific		All-cause
	COPD complexity		COPD complexity
	Low	Moderate/high	Low	Moderate/high
Insulinb	Reference	Reference	Reference	Reference
Metforminc	0.48 (0.35–0.67)	0.73 (0.53–1.01)	0.59 (0.50–0.69)	0.57 (0.42–0.78)
Sulfonyluread	0.60 (0.44–0.83)	0.81 (0.59–1.11)	0.69 (0.58–0.81)	0.68 (0.50–0.93)
Othere	0.70 (0.53–0.93)	0.94 (0.71–1.25)	0.86 (0.73–0.99)	0.85 (0.63–1.13)

Notes:

a Multivariable logistic regression model was used to estimate odds ratio, adjusted by age, gender, race, dual eligibility, prior-year hospitalization, DM complexity, comorbidities (GERD, anxiety and depression, CVD, sarcopenia, and osteoporosis), prior-year oxygen use, and COPD maintenance medications use.

b Those who had coexisting COPD and DM and received prescription for insulin during 2007–2010.

c Those who had coexisting COPD and DM and received prescription for metformin during 2007–2010.

d Those who had coexisting COPD and DM and received prescription for sulfonylurea during 2007–2010.

e Those who had coexisting COPD and DM and received antidiabetics prescription other than metformin, insulin, and sulfonylurea, such as acarbose, exenatide, glucagon, miglitol, nateglinide, pioglitazone, pramlintide, repaglinide, rosiglitazone, saxagliptin, or sitagliptin during 2007–2010.

Abbreviations: COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; DM, diabetes mellitus; ER, emergency room; GERD, gastroesophageal reflux disease.