Outcomes associated with concordance of oral antidiabetic drug treatments to prescribing information in patients with type 2 diabetes mellitus and chronic kidney disease

Figures & data

Figure 1. Drug-level analysis of OAD usage according PI recommendations. OAD, oral anti-diabetic drug; PI, prescribing information.

Table 1. Patient demographics, clinical characteristics, and healthcare costs and utilization at baseline evaluation period.

	PI-concordant (n = 846)	Non-PI-concordant (n = 2454)	p-value
Age (years): mean (SD)	55.8 (6.4)	56.0 (6.1)	0.400
Male (%)	56.7	64.0	<0.001
Plan types (%)			0.111
PPO	59.8	56.0
Comprehensive	1.1	0.8
HMO	31.9	36.6
Other	6.0	5.8
Geographical region (%)			0.036
Northeast	8.4	11.6
North central	11.7	9.3
South	59.9	59.4
West	20.0	19.7
CKD stage (%)			<0.001
Stage 3	78.8	84.7
Stage 4	10.6	9.8
Stage 5	10.5	5.4
CCI score: mean	1.8	1.4	<0.001
Glycemic measures*
HbA1c: mean (SD)	7.2% (1.6)	7.7% (2.0)	<0.001
Patients with glycemic control (%)	56.5	42.4	<0.001
Any specialist visit
Nephrologist	35.5	25.6	<0.01
Endocrinologist	16.0	11.8	<0.01
Ophthalmologist	26.1	24.3	0.30
Cardiologist	27.5	26.7	0.61
Use of insulin	39.2	32.2	<0.01
Any inpatient hospitalization	14.8	13.9	0.53
All-cause healthcare costs (per patient): mean (SD)
Total costs	15,521 (29,017)	13,519 (33,866)	<0.01
Inpatient costs	4322 (16,477)	4870 (25,782)	0.54
Outpatient costs	7688 (19,290)	5918 (15,162)	<0.01
Emergency room cost	387 (2157)	304 (1582)	0.77
Pharmacy costs	3124 (3597)	2427 (2662)	<0.01
DM-related healthcare costs (per patient): mean (SD)
Total costs	6212 (22,834)	5685 (14,591)	<0.01
Inpatient costs	3224 (13,473)	3841 (21,435)	0.68
Outpatient costs	1334 (2872)	1478 (4947)	0.22
Emergency room cost	146 (936)	134 (904)	0.82
Pharmacy costs	981 (971)	759 (873)	<0.01

CCI, Charlson comorbidity index; CKD, chronic kidney disease; HMO, health maintenance organization; PPO, preferred provider organization; PI, prescribing information; SD, standard deviation; DM, diabetes mellitus.

*Of the patients with known HbA_1c value at baseline (n = 1939).

Other health plans include exclusive provider organization and consumer-directed health plan.

Figure 2. Time to severe hypoglycemic event identified in all settings.

Figure 3. Time to severe hypoglycemic event identified in inpatient setting.

Table 2. Crude healthcare cost and clinical outcomes among PI-concordant and non-PI-concordant stages 3–5 CKD patients during 12-month follow-up period.

	PI-concordant mean (SD)	Non-PI-concordant Mean (SD)	p-value
Glycemic measures*
HbA1c: mean (SD)	7.2% (1.6)	7.6% (1.8)	<0.001
Patients with glycemic control (%)	58.1	43.8	<0.001
All-cause healthcare costs: mean (SD)
Total costs	30,227 (62,289)	26,317 (56,466)	<0.01
Inpatient costs	8668 (37,390)	9007 (36,795)	0.24
Outpatient costs	14,711 (34,922)	11,737 (31,368)	<0.01
Emergency room cost	616 (2584)	559 (1965)	0.75
Pharmacy costs	6233(7933)	5013 (5500)	<0.01
DM-related healthcare costs: mean (SD)
Total costs	10,843 (29,213)	10,433 (27,901)	0.10
Inpatient costs	5430 (21,709)	6331 (25,120)	0.26
Outpatient costs	2939 (10,840)	2638 (8107)	0.74
Emergency room cost	224 (1212)	278 (1261)	0.10
Pharmacy costs	1841(1995)	1596 (1840)	<0.01
Any inpatient hospitalization	17.9	19.7	0.23

PI, prescribing information; DM, diabetes mellitus; SD, standard deviation.

*Of the patients with known HbA_1c value at follow-up period (n = 1842).

Table 3. Regression results for risk of severe hypoglycemic event.

	Severe hypoglycemic events identified from all settings (hazard ratio, 95% CI)		p-value	Severe hypoglycemic events identified from inpatient setting (hazard ratio, 95% CI)		p-value
Non-concordant	1.35	(1.10–1.67)	<0.01	2.51	(1.49–4.22)	<0.01
Age categories (ref: 18–54)
55–64	0.99	(0.82–1.19)	0.93	1.66	(1.10–2.50)	0.02
Gender (ref: male)
Female	0.83	(0.69–0.99)	0.04	0.75	(0.51–1.10)	0.14
Region (ref: South)
Northeast	0.93	(0.67–1.27)	0.63	1.61	(0.92–2.80)	0.09
Midwest	1.05	(0.74–1.49)	0.78	1.15	(0.54–2.43)	0.71
West	1.57	(1.24–2.00)	<0.01	1.64	(1.02–2.65)	0.04
CCI categories (ref: CCI = 0–1)
CCI = 2	1.61	(1.24–2.09)	<0.01	0.96	(0.57–1.60)	0.87
CCI ≥ 3	2.14	(1.62–2.82)	<0.01	1.68	(1.06–2.67)	0.03
CKD stage (ref: CKD = 3)
CKD 4–5	1.11	(0.90–1.38)	0.32	1.39	(0.92–2.12)	0.12
Plan type (ref: non-HMO)
HMO	1.07	(0.87–1.32)	0.53	1.26	(0.81–1.96)	0.31
Any visit to nephrologists during the baseline period	1.08	(0.86–1.36)	0.53	1.41	(0.91–2.19)	0.12
Any visit to endocrinologist during the baseline period	1.15	(0.89–1.48)	0.28	0.78	(0.44–1.41)	0.41
Any inpatient hospitalization during the baseline period	1.30	(1.03–1.63)	0.03	2.07	(1.37–3.12)	<0.01
Any use of insulin during the baseline period	1.99	(1.66–2.38)	<0.01	1.49	(1.03–2.15)	0.03

CCI, Charlson comorbidity index; CKD, chronic kidney disease; HMO, health maintenance organization; CI, confidence interval.

Table 4. Regression results for glycemic control and annual inpatient admissions.

	Glycemic control* (odds ratio, 95% CI)		p-value	Annual inpatient admission (odds ratio, 95% CI)		p-value
Non-concordant	0.56	(0.44–0.71)	<0.01	1.27	(1.02–1.57)	0.03
Age categories (ref: 18–54)
55–64	0.96	(0.78–1.19)	0.73	0.93	(0.77–1.12)	0.44
Gender (ref: male)
Female	1.22	(0.99–1.49)	0.06	0.96	(0.80–1.16)	0.66
Region (ref: South)
Northeast	0.81	(0.60–1.10)	0.17	1.38	(1.03–1.86)	0.03
Midwest	1.74	(1.16–2.59)	0.01	1.20	(0.87–1.66)	0.26
West	1.42	(1.06–1.92)	0.02	0.94	(0.71–1.23)	0.64
CCI categories (ref: CCI = 0–1)
CCI = 2	0.91	(0.70–1.19)	0.50	1.15	(0.90–1.49)	0.27
CCI ≥ 3	1.13	(0.83–1.54)	0.44	1.55	(1.18–2.04)	<0.01
CKD stage (ref: CKD = 3)
CKD 4–5	1.43	(1.06–1.92)	0.02	1.77	(1.41–2.21)	<0.01
Plan type (ref: non-HMO)
HMO	1.02	(0.82–1.27)	0.88	1.06	(0.85–1.31)	0.63
Any visit to nephrologists during the baseline period	1.35	(1.02–1.79)	0.04	1.02	(0.80–1.31)	0.86
Any visit to endocrinologist during the baseline period	1.01	(0.74–1.37)	0.95	0.75	(0.57–1.01)	0.05
Any inpatient hospitalization during the baseline period	0.97	(0.70–1.35)	0.87	2.66	(2.12–3.34)	<0.01
Any use of insulin during the baseline period	0.29	(0.23–0.36)	<0.01	1.74	(1.44–2.10)	<0.01

CCI, Charlson comorbidity index; CKD, chronic kidney disease; HMO, health maintenance organization, CI, confidence interval.

*Limited to 1842 patients who have HbA_1c results during follow-up period.

Figure 4. Adjusted 1-year cost differences associated with non-concordance to prescribing information. Model adjusted for age, gender, geographical region, CCI score, CKD stage, visits to specialists, insulin use, and any inpatient hospitalization during the baseline period. *Statistically significant at p < 0.05 compared to PI-concordant cohort.