Insulin adherence and persistence among Chinese patients with type 2 diabetes: a retrospective database analysis

Figures & data

Table 1 Baseline characteristics of the total cohort (N=24,192)

Baseline characteristics	Total cohort N=24,192
Demographic characteristics
Mean age, mean (SD)	58.9 (11.5)
Age group, n (%)
<40	1,013 (4.2)
[40–49]	3,574 (14.8)
[50–59]	9,105 (37.6)
[60–69]	5,735 (23.7)
≥70	4,765 (19.7)
Female, n (%)	11,976 (49.5)
Retired, n (%)	16,833 (69.6)
Index insulin source, n (%)
Human insulin	12,547 (51.9)
Insulin analog	9,461 (39.1)
Animal-derived insulin	2,184 (9.0)
Index insulin action profile, n (%)
Prandial insulin	2,628 (10.9)
Basal insulin	2,865 (11.8)
Premixed insulin	18,699 (77.3)
Index insulin administration, n (%)
Vials and syringes	2,606 (10.8)
Pens	21,586 (89.2)
Count of A1c tests, mean (SD)	0.34 (0.64)
Any claims-based hypoglycemic events, n (%)	191 (0.8)
Comorbidities and complications, n (%)
CCI, mean (SD)	1.98 (1.44)
Hypertension	12,039 (49.8)
Dyslipidemia	6,340 (26.2)
Retinopathy	4,057 (16.8)
Neuropathy	5,579 (23.1)
Nephropathy	4,167 (17.2)
Count of unique OAD drug classes, mean (SD)	2.22 (1.30)
Metformin	10,190 (42.1)
Sulfonylureas	8,268 (34.2)
Meglitinides	12,551 (51.9)
Thiazolidinediones	6,458 (26.7)
α-Glucosidase inhibitors	16,324 (67.5)
Any hospitalizations, n (%)	5,477 (22.6)
Direct medical cost ($), mean (SD)	845 (1,493)

Abbreviations: SD, standard deviation; CCI, Charlson Comorbidity Index; OAD, oral antidiabetic medication.

Table 2 Unadjusted adherence and persistence in total cohort and subgroups

Subgroups		MPR		Time to nonpersistence
		Mean (SD)	P-value	Mean (SD)	P-value
Total cohort	(N=24,192)	0.499 (0.361)		230.3 (145.5)
Gender subgroup			0.097a		0.540a
Male	(N=12,216)	0.495 (0.359)		230.9 (145.4)
Female	(N=11,976)	0.503 (0.364)		229.8 (145.5)
Age subgroup			<0.001b		0.775b
<40	(N=1,013)	0.399 (0.348)		185.0 (149.2)
[40–44]	(N=885)	0.485 (0.358)		220.0 (146.8)
[45–49]	(N=2,689)	0.555 (0.364)		243.1 (144.3)
[50–54]	(N=4,392)	0.571 (0.364)		249.7 (142.3)
[55–59]	(N=4,713)	0.546 (0.362)		243.7 (143.6)
[60–64]	(N=3,432)	0.513 (0.357)		235.5 (144.8)
[65–69]	(N=2,303)	0.466 (0.348)		224.1 (144.4)
[70–74]	(N=2,169)	0.414 (0.341)		214.2 (144.1)
[75–79]	(N=1,597)	0.382 (0.335)		201.5 (144.8)
≥80	(N=999)	0.328 (0.319)		180.4 (141.3)
Index insulin source			<0.001b		<0.001b
Human	(N=12,547)	0.509 (0.365)		225.8 (146.8)
Analog	(N=9,461)	0.540 (0.356)		242.9 (144.4)
Animal	(N=2,184)	0.269 (0.270)		202.2 (136.3)
Index insulin action profile			<0.001b		<0.001b
Mealtime	(N=2,628)	0.294 (0.287)		205.8 (137.3)
Basal	(N=2,865)	0.522 (0.343)		239.0 (143.8)
Premixed	(N=18,699)	0.524 (0.364)		232.5 (146.5)
Index insulin administration			<0.001a		<0.001a
Vials and syringes	(N=2,606)	0.295 (0.287)		207.7 (137.4)
Pens	(N=21,586)	0.524 (0.362)		233.1 (146.2)

Notes:

a Student’s t-test,

b ANOVA.

Abbreviations: MPR, medication possession ratio; SD, standard deviation; ANOVA, analysis of variance.

Figure 1 Kaplan–Meier curve for insulin persistence during follow-up period.

Table 3 Unadjusted and adjusted characteristics for insulin adherent and nonadherent cohorts during 12-month follow-up period

Patient characteristics	Adherent N=7,486	Nonadherent N=16,706	Unadjusted analysis			Adjusted analysis
			OR	95% CI	P-value	OR	95% CI	P-value
Age group, n (%)
<40	224 (3.0)	789 (4.7)	1.24	1.05–1.47	0.009	1.13	0.93–1.37	0.224
[40–49]	1,263 (16.9)	2,311 (13.8)	2.40	2.17–2.65	<0.001	2.09	1.83–2.40	<0.001
[50–59]	3,458 (46.2)	5,647 (33.8)	2.68	2.47–2.92	<0.001	2.07	1.88–2.28	<0.001
[60–69]	1,656 (22.1)	4,079 (24.4)	1.78	1.62–1.95	<0.001	1.41	1.28–1.56	<0.001
≥70	885 (11.8)	3,880 (23.2)	1 (reference)			1 (reference)
Female, n (%)	3,807 (50.9)	8,169 (48.9)	1.08	1.02–1.14	0.005	0.95	0.89–1.01	0.100
Retired, n (%)	5,087 (68.0)	11,746 (70.3)	0.90	0.84–0.95	<0.001	1.32	1.20–1.45	<0.001
Index insulin source, n (%)
Human insulin	4,102 (54.8)	8,445 (50.6)	1 (reference)			1 (reference)
Insulin analog	3,215 (42.9)	6,246 (37.4)	1.06	1.00–1.12	0.045	1.07	1.00–1.14	0.036
Animal-derived insulin	169 (2.3)	2,015 (12.1)	0.17	0.15–0.20	<0.001	0.46	0.36–0.59	<0.001
Index insulin action profile, n (%)
Prandial insulin	264 (3.5)	2,364 (14.2)	0.22	0.19–0.25	<0.001	0.55	0.45–0.68	<0.001
Basal insulin	870 (11.6)	1,995 (11.9)	0.85	0.78–0.92	<0.001	0.79	0.72–0.87	<0.001
Premixed insulin	6,352 (84.9)	12,347 (73.9)	1 (reference)			1 (reference)
Count of A1c tests, mean (SD)	0.38 (0.66)	0.32 (0.63)	1.16	1.11–1.20	<0.001	1.19	1.13–1.25	<0.001
Any claims-based hypoglycemic events, n (%)	35 (0.5)	166 (1.0)	0.47	0.32–0.67	<0.001	0.62	0.42–0.91	0.015
Comorbidities and complications
CCI, mean (SD)	1.64 (1.21)	2.13 (1.51)	0.75	0.73–0.76	<0.001	0.93	0.91–0.96	<0.001
Hypertension, n (%)	2,411 (32.2)	9,628 (57.6)	0.35	0.33–0.37	<0.001	0.47	0.44–0.50	<0.001
Dyslipidemia, n (%)	1,378 (18.4)	4,967 (29.7)	0.53	0.50–0.57	<0.001	0.74	0.68–0.80	<0.001
Retinopathy, n (%)	1,268 (16.9)	2,789 (16.7)	1.02	0.95–1.09	0.639	0.98	0.91–1.07	0.698
Neuropathy, n (%)	2,146 (28.7)	3,433 (20.5)	1.55	1.46–1.65	<0.001	1.33	1.24–1.43	<0.001
Nephropathy, n (%)	1,653 (22.1)	2,514 (15.0)	1.60	1.49–1.71	<0.001	1.40	1.30–1.52	<0.001
Count of unique OAD drug classes, mean (SD)	2.45 (1.28)	2.12 (1.29)	1.21	1.18–1.24	<0.001	1.16	1.13–1.19	<0.001
Any hospitalizations, n (%)	1,127 (15.1)	4,350 (26.0)	0.50	0.47–0.54	<0.001	0.94	0.86–1.02	0.148
Direct medical cost ($), mean (SD)	753 (1,430)	887 (1,519)	0.96	0.94–0.97	<0.001	0.97	0.95–0.99	0.006

Note: OR >1 indicates that patients were more likely to be adherent than the reference group.

Abbreviations: SD, standard deviation; OR, odds ratio; CI, confidence interval; CCI, Charlson Comorbidity Index; OAD, oral antidiabetic medication.

Table 4 Unadjusted and adjusted characteristics for insulin persistent and nonpersistent cohorts during 12-month follow-up period

Patient characteristics	Persistent N=12,823	Nonpersistent N=11,369	Unadjusted analysis			Adjusted analysis
			HR	95% CI	P-value	HR	95% CI	P-value
Age group, n (%)
<40	397 (3.1)	616 (5.4)	1.16	1.07–1.27	0.001	1.24	1.11–1.39	<0.001
[40–49]	1,990 (15.5)	1,584 (13.9)	0.71	0.67–0.76	<0.001	0.80	0.74–0.88	<0.001
[50–59]	5,329 (41.6)	3,776 (33.2)	0.65	0.62–0.68	<0.001	0.77	0.73–0.82	<0.001
[60–69]	3,047 (23.8)	2,688 (23.6)	0.76	0.72–0.81	<0.001	0.89	0.84–0.94	<0.001
≥70	2,060 (16.1)	2,705 (23.8)	1 (reference)			1 (reference)
Female, n (%)	6,319 (49.3)	5,657 (49.8)	1.01	0.98–1.05	0.463	1.07	1.02–1.11	0.002
Retired, n (%)	8,881 (69.3)	7,952 (69.9)	1.01	0.97–1.06	0.509	0.86	0.81–0.92	<0.001
Index insulin source, n (%)
Human insulin	6,494 (50.6)	6,053 (53.2)	1 (reference)			1 (reference)
Insulin analog	5,445 (42.5)	4,016 (35.3)	0.84	0.81–0.87	<0.001	0.88	0.85–0.92	<0.001
Animal-derived insulin	884 (6.9)	1,300 (11.4)	1.27	1.19–1.34	<0.001	1.01	0.89–1.16	0.860
Index insulin action profile, n (%)
Prandial insulin	1,099 (8.6)	1,529 (13.4)	1.31	1.24–1.38	<0.001	1.24	1.09–1.40	0.001
Basal insulin	1,612 (12.6)	1,253 (11.0)	0.92	0.87–0.98	0.010	0.98	0.92–1.05	0.539
Premixed insulin	10,112 (78.9)	8,587 (75.5)	1 (reference)			1 (reference)
Count of A1c tests, mean (SD)	0.39 (0.67)	0.27 (0.60)	0.77	0.75–0.80	<0.001	0.81	0.78–0.84	<0.001
Any claims-based hypoglycemia events, n (%)	79 (0.6)	122 (1.1)	1.50	1.26–1.80	<0.001	1.44	1.20–1.74	<0.001
Comorbidities and complications
CCI, mean (SD)	1.79 (1.34)	2.19 (1.52)	1.13	1.12–1.14	<0.001	1.01	0.99–1.02	0.228
Hypertension, n (%)	5,063 (39.5)	6,976 (61.4)	1.97	1.90–2.05	<0.001	1.80	1.71–1.88	<0.001
Dyslipidemia, n (%)	2,750 (21.4)	3,590 (31.6)	1.48	1.43–1.54	<0.001	1.19	1.14–1.25	<0.001
Retinopathy, n (%)	2,156 (16.8)	1,901 (16.7)	1.00	0.95–1.05	0.985	1.04	0.99–1.10	0.142
Neuropathy, n (%)	3,483 (27.2)	2,096 (18.4)	0.68	0.65–0.71	<0.001	0.81	0.77–0.85	<0.001
Nephropathy, n (%)	2,616 (20.4)	1,551 (13.6)	0.69	0.65–0.72	<0.001	0.77	0.73–0.82	<0.001
Count of unique OAD drug classes, mean (SD)	2.38 (1.29)	2.05 (1.28)	0.86	0.85–0.87	<0.001	0.86	0.84–0.87	<0.001
Any hospitalizations, n (%)	2,824 (22.0)	2,653 (23.3)	0.98	0.94–1.03	0.455	0.64	0.60–0.68	<0.001
Direct medical cost ($), mean (SD)	798 (1,456)	898 (1,532)	1.14	1.12–1.16	<0.001	1.16	1.14–1.18	<0.001

Note: HR >1 indicates that patients were less likely to be persistent than the reference group.

Abbreviations: SD, standard deviation; HR, hazard ratio; CI, confidence interval; CCI, Charlson Comorbidity Index; OAD, oral antidiabetic medication.