Glycemic control among patients with type 2 diabetes who initiate basal insulin: a retrospective cohort study

Figures & data

Figure 1. Inclusion–exclusion criteria and sample size.

Table 1. Descriptive statistics.

	n or Mean	% or SD
Patient characteristics
Age group
21–44	1550	10.72
45–54	3035	20.99
55–64	4413	30.52
65–71	2340	16.18
72+	3120	21.58
Sex
Female	7197	49.78
Male	7261	50.22
Race
African American	2444	16.90
Asian	184	1.27
Caucasian	9168	63.41
Other/Unknown	2662	18.41
Region
Midwest	5034	34.82
Northeast	604	4.18
Other/Unknown	15	0.10
South	6622	45.80
West	2183	15.10
Insurance type
Commercial	3170	21.93
Medicaid	244	1.69
Medicare	2622	18.14
Other payor type	192	1.33
Uninsured	804	5.56
Unknown	7426	51.36
Household income (mean; SD)*	42,906.20	11,229.54
% College Educated (mean; SD)*	23.44	7.71
Pre-period anti-diabetic therapy use
Prandial Insulin	1040	7.19
Pre-Mix Insulin	501	3.47
Orals	10,328	71.43
GLP-1 Agonist	1189	8.22
Pre-period comorbidities
Diabetic Retinopathy	625	4.32
Diabetic Neuropathy	1427	9.87
Coronary Artery Disease	2851	19.72
Myocardial Infarction	590	4.08
Peripheral Vascular Disease	934	6.46
Congestive Heart Failure	1241	8.58
Hypertension	10,075	69.68
Depression	1733	11.99
Cancer	824	5.70
Obesity	714	4.94
Chronic Kidney Disease	862	5.96
Pre-period general health
CCI (mean; SD)	0.67	1.18
Pre-period glycemic control
HbA1c (mean; SD)	8.59	2.35
Pre-period CKD status (based on eGFR)
Normal	7241	50.08
Mild	3833	26.55
Moderate	1977	13.67
Severe	448	3.10
ESRD	234	1.62
Missing	720	4.98

*Based upon 3-digit zip code of residence.

Table 2. Descriptive statistics, by change in HbA1c categories.

	Improve (n = 7619)		Unchanged (n = 3077)		Worse (n = 3761)		p-Value
	n or Mean	% or SD	n or Mean	% or SD	n or Mean	% or SD
Patient characteristics
Age							A,B,C
21–44	816	10.71	272	8.84	461	12.26
45–54	1690	22.18	508	16.51	837	22.25
55–64	2405	31.57	927	30.13	1081	28.74
65–71	1167	15.32	571	18.56	602	16.01
72+	1541	20.23	799	25.97	780	20.74
Sex							B,C
Female	3727	48.92	1518	49.33	1952	51.90
Male	3892	51.08	1559	50.67	1809	48.10
Race							A,B,C
African American	1278	16.77	458	14.88	707	18.80
Asian	92	1.21	53	1.72	39	1.04
Caucasian	4843	63.56	2013	65.42	2312	61.47
Other/Unknown	1406	18.45	553	17.97	703	18.69
Region							A,B,C
Midwest	2674	35.10	1085	35.26	1274	33.87
Northeast	350	4.59	111	3.61	143	3.80
Other/unknown	6	0.08	5	0.16	4	0.11
South	3327	43.67	1429	46.44	1866	49.61
West	1272	16.56	447	14.53	474	12.60
Insurance type							A,B
Commercial	1817	23.85	606	19.59	747	19.86
Medicaid	127	1.67	43	1.40	74	1.97
Medicare	1350	17.72	588	19.11	684	18.19
Other payor type	115	1.51	37	1.20	40	1.06
Uninsured	454	5.96	143	4.65	207	5.50
Unknown	3756	49.30	53.95	53.95	2009	53.42
Household income (mean; SD)*	43,226.81	11,237.87	42,859.99	11,268.79	42,293.34	11,158.40	B,C
% College Educated (mean; SD)*	23.56	7.71	23.39	7.91	23.25	7.55	B
Pre-period anti-diabetic therapy use
Prandial Insulin	508	6.67	248	8.06	284	7.55	A
Pre-Mix Insulin	248	3.26	117	3.80	136	3.62	A
Orals	5710	74.94	2063	67.05	2555	67.93	B
GLP-1 Agonist	627	8.23	254	8.25	308	8.19	A
Pre-period comorbidities
Diabetic Retinopathy	331	4.34	130	4.22	164	4.36
Diabetic Neuropathy	762	10.00	295	9.59	370	9.84
Coronary Artery Disease	1429	18.76	682	22.16	740	19.68	A,C
Myocardial Infarction	296	3.89	155	5.04	139	3.70	A,C
Peripheral Vascular Disease	485	6.37	208	6.76	241	6.41
Congestive Heart Failure	608	7.98	258	8.38	375	9.97	B,C
Hypertension	5318	69.80	2155	70.04	2602	69.18
Depression	881	11.56	384	12.48	468	12.44
Cancer	446	5.85	184	5.98	194	5.16
Obesity	394	5.17	128	4.16	192	5.11	A
Chronic Kidney Disease	420	5.51	198	6.43	244	6.49	B
Pre-period general health
CCI (mean; SD)	0.66	1.19	0.67	1.19	0.67	1.16
Glycemic control
Pre-Period HbA1c (mean; SD)	9.62	2.07	7.79	1.51	7.86	1.57	A,B
Days between pre- and post-period HbA1c (mean; SD)	635.51	172.77	653.58	178.25	663.03	175.15	A,B,C
Pre-period eGFR							A,C
Normal	3947	51.80	1420	46.15	1874	49.83
Mild	1971	25.87	898	29.18	969	25.76
Moderate	988	12.97	450	14.62	539	14.33
Severe	229	3.01	104	3.38	115	3.06
ESRD	113	1.48	51	1.66	70	1.86
Missing	371	4.87	154	5.00	194	5.16

A, statistically significant difference (p < 0.05) between Improved and Unchanged cohorts; B, statistically significant difference (p < 0.05) between Improved and Worse cohorts; C, statistically significant difference (p < 0.05) between Unchanged and Worse cohorts.

*Based upon 3-digit zip code of residence.

Table 3. Associations with post-period glycemic control.

	Coefficient	p-Value
Intercept	5.6333	<0.0001
Age 45–54^a	−0.3196	<0.0001
Age 55–64^a	−0.5821	<0.0001
Age 65–71^a	−0.6630	<0.0001
Age 72+^a	−0.7544	<0.0001
Female^b	0.0409	0.1372
African-American^c	0.1930	<0.0001
Other/Unknown Race^c	0.0180	0.8813
Northeast^d	−0.0828	0.2997
Midwest^d	−0.0010	0.9766
West^d	−0.1948	<0.0001
Commercial Insurance^e	−0.0359	0.3068
Medicare^e	−0.0953	0.0138
Other/Unknown Insurance^e	−0.1297	0.1042
Household Income*	−0.0064	0.0065
% College Educated	0.0044	0.1426
CCI	0.0297	0.1701
Diabetic Retinopathy^f	0.0449	0.5244
Diabetic Neuropathy^f	0.0409	0.4815
Coronary Artery Disease^f	0.0204	0.6076
Myocardial Infarction^f	−0.1266	0.1080
Peripheral Vascular Disease^f	−0.1628	0.0072
Congestive Heart Failure^f	0.0408	0.4688
Hypertension^f	−0.0104	0.7373
Depression^f	−0.0163	0.6993
Cancer^f	−0.2446	0.0019
Obesity^f	−0.2320	0.0002
Prandial Insulin Use^f	0.1375	0.0087
Pre-Mix Insulin Use^f	0.2671	0.0003
Oral use^f	0.0301	0.3321
GLP-1 Agonist Use^f	0.0507	0.3092
Pre-Period HbA1c	0.3333	<0.0001
Months Pre to Post HbA1c	0.0003	<0.0001
Pre-Period Mild CKD^g	−0.0425	0.2476
Pre-Period Moderate CKD^g	−0.1179	0.0103
Pre-Period Severe CKD^g	−0.3857	<0.0001
Pre-Period ESRD^g	−0.2907	0.0075
Pre-Period Missing CKD^g	−0.0387	0.5429

*Household income in tens of thousands.

^areference category Age 21–45; ^breference category Males; ^creference category Caucasian; ^dreference category South; ^ereference category Medicaid or Uninsured; ^freference category no receipt of diagnosis or drug of interest; ^greference category no CKD.

Italics represent statistically significant variables (p < 0.05).

Table 4. Predictors of changes in glycemic control.

	Worse vs Unchanged		Improved vs Unchanged
	Odds ratio	95% CI	Odds ratio	95% CI
Age 45–54^a	0.958	0.793–1.158	1.301	1.070–1.583
Age 55–64^a	0.674	0.561–0.809	1.321	1.096–1.592
Age 65–71^a	0.582	0.470–0.720	1.287	1.040–1.593
Age 72+^a	0.526	0.423–0.653	1.374	1.106–1.708
Female^b	1.086	0.982–1.200	1.061	0.963–1.169
African-American Black^c	1.183	1.030–1.358	0.932	0.810–1.073
Other/Unknown Race^c	0.640	0.417–0.981	0.652	0.443–0.959
Northeast^d	1.133	0.835–1.537	1.292	0.972–1.717
Midwest^d	0.939	0.831–1.062	0.946	0.838–1.068
West^d	0.865	0.740–1.011	1.202	1.041–1.389
Commercial Insurance^e	0.913	0.802–1.041	1.034	0.912–1.171
Medicare^e	1.040	0.906–1.192	1.163	1.019–1.327
Other/Unknown Insurance^e	1.023	0.757–1.381	1.205	0.897–1.620
Household Income*	0.993	0.985–1.002	1.004	0.996–1.012
% College Educated	1.008	0.997–1.019	0.999	0.989–1.010
CCI	1.050	0.969–1.138	1.021	0.949–1.099
Diabetic Retinopathy^f	1.059	0.820–1.369	0.992	0.775–1.269
Diabetic Neuropathy^f	0.981	0.794–1.212	1.027	0.842–1.253
Coronary Artery Disease^f	0.965	0.838–1.110	0.969	0.848–1.108
Myocardial Infarction^f	0.681	0.515–0.899	0.821	0.631–1.068
Peripheral Vascular Disease^f	0.987	0.792–1.229	1.109	0.901–1.365
Congestive Heart Failure^f	1.331	1.089–1.627	1.148	0.943–1.397
Hypertension^f	1.000	0.894–1.119	1.021	0.915–1.138
Depression^f	0.948	0.815–1.102	0.920	0.794–1.065
Cancer^f	0.861	0.647–1.147	1.146	0.877–1.497
Obesity^f	1.112	0.878–1.407	1.288	1.021–1.624
Prandial Insulin Use^f	0.936	0.781–1.123	0.858	0.719–1.025
Pre-Mix Insulin Use^f	0.948	0.732–1.226	0.794	0.615–1.024
Oral use^f	1.059	0.950–1.180	1.211	1.087–1.351
GLP-1 Agonist Use^f	0.922	0.770–1.104	0.950	0.801–1.127
Pre-Period HbA1c	0.994	0.961–1.028	1.974	1.904–2.047
Months Pre to Post HbA1c	1.000	1.000–1.001	1.000	1.000–1.000
Pre-Period Mild CKD^g	0.989	0.865–1.129	0.993	0.875–1.128
Pre-Period Moderate CKD^g	1.107	0.941–1.303	1.186	1.013–1.388
Pre-Period Severe CKD^g	0.941	0.705–1.258	1.479	1.124–1.946
Pre-Period ESRD^g	1.137	0.778–1.662	1.694	1.163–2.469
Pre-Period Missing CKD^g	1.012	0.806–1.272	1.172	0.937–1.466

*Household income in tens of thousands.

^areference category Age 21–45; ^breference category Males; ^creference category Caucasian; ^dreference category South; ^ereference category Medicaid or Uninsured; ^freference category no receipt of diagnosis or drug of interest; ^greference category no CKD.

Italics represent statistically significant variables (p < 0.05).