Clinical Inertia and 2-Year Glycaemic Trajectories in Patients with Non-Newly Diagnosed Type 2 Diabetes Mellitus in Primary Care: A Retrospective Cohort Study

Figures & data

Table 1 Demographic and Clinical Characteristics for the Overall Study Population and for the 4 Groups with Different Cumulative Glycaemic Exposures

Variables	n	Overall	Group 1	Group 2	Group 3	Group 4	Z/χ^2	P
n (%)		4690 (100.0)	1616 (34.5)	642 (13.7)	761 (16.2)	1671 (35.6)
Demographics
Age, years	4690	61.75 (55.83, 67.35)	62.00 (56.33, 67.33)	61.47±8.60	61.30±8.66	61.39±8.77	0.825	0.480
Sex (male) (n,%)		2475 (52.8)	873 (54.0)	338 (52.6)	402 (52.8)	862 (51.6)	1.962	0.580
Diabetes duration (years)	4690	9.58 (6.33, 14.25)	9.08 (5.75, 12.65)	9.33 (6.25, 13.50)*	9.83 (6.58, 14.33)**	10.42 (6.92, 15.25)**	68.744	0.000
≥10 (n,%)		2201 (46.9)	661 (40.9)	292 (45.5)*	365 (48.0)**	883 (52.8)**	47.887	0.000
Education (n,%)	4106						19.060	0.000
Below high school		2292 (55.8)	726 (51.3)	330 (59.0)**	368 (56.6)*	868 (58.6)**
Above high school		1814 (44.2)	690 (48.7)	229 (41.0)	282 (43.4)	613 (41.4)
Comorbidities/complications
Hypertension (n,%)	4690	2682 (57.2)	891 (55.1)	383 (59.7)	465 (61.1)**	943 (56.4)	9.532	0.023
Dyslipidemia (n,%)	4690	3287 (70.1)	1103 (68.3)	460 (71.7)	539 (70.8)	1185 (70.9)	4.083	0.253
Hypercholesterolemia	4339	2883 (66.4)	925 (61.9)	398 (66.2)	491 (69.4)**	1069 (69.6)**	23.746	0.000
High triglyceridemia	4340	1956 (45.1)	589 (39.4)	282 (46.9)**	324 (45.8)**	761 (49.5)**	32.818	0.000
CVD (n,%)	4690	1146 (24.4)	374 (23.1)	171 (26.6)	187 (24.6)	414 (24.8)	3.256	0.354
PAD (n,%)	4690	1060 (22.6)	355 (22.0)	127 (19.8)	184 (24.2)	394 (23.6)	5.283	0.152
Retinopathy (n,%)	4690	831 (17.7)	203 (12.6)	104 (16.2)*	147 (19.3)**	377 (22.6)**	58.705	0.000
DKD (n,%)	4690	642 (13.7)	174 (10.8)	85 (13.2)	116 (15.2)**	267 (16.0)**	20.754	0.000
Neuropathy (n,%)	4690	2606 (55.6)	830 (51.4)	351 (54.7)	406 (53.4)	1019 (61.0)**	33.139	0.000
Baseline characteristics
BMI (kg/m^2)	4690	24.72 (22.89, 26.79)	24.64 (22.77, 26.64)	24.61 (23.03, 26.82)	24.65 (22.89, 26.79)	24.80 (23.03, 26.99)*	5.050	0.168
BMI (kg/m^2) (n,%)	4690						7.648	0.265
<24.0		1831 (39.0)	665 (41.2)	250 (38.9)	298 (39.2)	618 (37.0)*
24.0~27.9		2133 (45.5)	723 (44.7)	288 (44.9)	340 (44.7)	782 (46.8)
≥28		726 (15.5)	228 (14.1)	104 (16.2)	123 (16.2)	271 (16.2)
Anti-diabetic Treatment (n,%)	4690						400.190	0.000
Non-insulin		1932 (41.2)	952 (58.9)	288 (44.9)**	272 (35.7)**	420 (25.1)**
Insulin usage		2758 (58.8)	664 (41.1)	354 (55.1)	489 (64.3)	1251 (74.9)
Adherence to exercise (n,%)	4156	2343 (56.4)	818 (57.3)	313 (54.8)	363 (53.4)	849 (57.5)	4.254	0.235
Adherence to diet (n,%)	3344	1825 (54.6)	654 (56.7)	249 (54.0)	294 (53.5)	628 (53.2)	3.354	0.340
Adherence to medication (n,%)	2765	2248 (81.3)	802 (83.0)	314 (80.9)	334 (77.0)**	798 (81.7)	7.395	0.060
Adherence to SMBG (n,%)	2759	1391 (50.4)	536 (55.1)	180 (46.5)**	198 (46.2)**	477 (49.1)**	14.817	0.002
Follow up characteristics
Follow up≥24 months (n,%)	4690	2403 (51.2)	824 (51.0)	381 (59.3)**	382 (50.2)	816 (48.8)	21.129	0.000
HbA1c measurements (number)	4690	4.00 (3.00, 6.00)	5.00 (3.00, 6.00)	6.00 (4.00, 7.00)	4.00 (3.00, 5.00)	4.00 (3.00, 6.00)	296.979	0.000
HbA1c measurements /year (n,%)	4690						129.241	0.000
<2		1291 (27.5)	417 (25.8)	96 (15.0)	262 (34.4)	516 (30.9)
2~<3		1887 (40.3)	612 (37.9)	260 (40.5)	299 (39.3)	716 (42.8)
≥3		1512 (32.2)	587 (36.3)	286 (44.5)	200 (26.3)	439 (26.3)
Share-care (n,%)	4690	2420 (51.6)	720 (44.6)	358 (55.8)**	390 (51.2)**	952 (57.0)**	55.921	0.000
Treatment change (n,%)	4690	2118 (45.2)	658 (40.7)	303 (47.2)**	341 (44.8)	816 (48.8)**	23.091	0.000
Anti-diabetic Treatment (n,%)	4690						443.552	0.000
Non-insulin		1957(41.7)	976(60.4)	292(45.5)**	276(36.3)**	413(24.7)**
Insulin usage		2733(58.3)	640(39.6)	350(54.5)	485(63.7)	1258(75.3)
Adherence to exercise (n,%)	3667	2534 (69.1)^#	935 (75.6)^#	365 (70.2)*^#	380 (67.6)**^#	854 (63.4)**^#	46.096	0.000
Adherence to diet (n,%)	3208	2102 (65.5)^#	840 (76.8)^#	302 (65.8)**^#	304 (61.4)**^#	656 (56.6)**	106.438	0.000
Adherence to medication (n,%)	3676	3375 (91.8)^#	1182 (95.3)^#	480 (92.3)*^#	515 (91.6)**^#	1198 (88.5)**^#	40.533	0.000
Adherence to SMBG (n,%)	3661	2149 (58.7)^#	828 (66.9)^#	312 (59.8)**^#	330 (59.0)**^#	679 (50.6)**	70.813	0.000

Notes: Data are numbers (%), medians (interquartile range (IQR)) or mean±standard deviation. Beginning with the second available HbA_1c measure: Group 1: ≥90% of HbA_1c measurements <7.5%; Group 2: 60~89% of HbA_1c measurements <7.5%; Group 3: 30~59% of HbA_1c measurements <7.5%; Group 4: <30% of HbA_1c measurements <7.5%. Hypercholesterolemia: baseline cholesterol≥4.50 (mmol/L); High Triglyceridemia: baseline Triglyceride ≥1.70 (mmol/L). The proportion of cases in the whole. *P<0.05 vs group 1; **P<0.01 vs group 1. ^#P<0.01 follow up vs baseline.

Abbreviations: BMI, body mass index; CVD, cardiovascular disease; PAD, peripheral arterial disease; OAD, oral anti-diabetic drugs; DKD, diabetic kidney disease; HbA1c, haemoglobin A1c.

Table 2 HbA_1c Value and Number of Measurements for the Overall Study Population and for the 4 Groups with Different Cumulative Glycaemic Exposures

Visit of Follow Up	n	Overall	Group 1	Group 2	Group 3	Group 4	χ^2	P
Baseline	4690	7.50 (6.60, 8.80)	6.60 (6.20, 7.20)	7.10 (6.60, 7.80)**	7.70 (7.10, 8.90)**	8.70 (7.80, 9.80)**	1761.711	0.000
<7.50		2249(48.0)	1295(80.1)	403(62.8)**	303(39.8)**	248(14.8)**	1544.591	0.000
7.50~8.90		1347(28.7)	221(13.7)	156(24.3)	278(36.5)	692(41.4)
≥9.00		1094(23.3)	100(6.2)	83(12.9)	180(23.7)	731(43.7)
Visit 1	4357	7.30 (6.50, 8.40)	6.40 (6.00, 6.80)	7.00 (6.50, 7.40)**	7.40 (7.00, 8.00)**	8.60 (7.90, 9.60)**	2833.385	0.000
Change from baseline to visit 1	4357	−0.10 (−0.80, 0.40)	−0.20 (−0.60, 0.10)	−0.20 (−0.90, 0.30)	−0.20 (−1.10, 0.40)	0.00 (−0.80, 0.80)**	80.194	0.000
<-0.5%	4357	2838 (65.1)	986 (67.4)	383 (64.2)	415 (57.2)**	1054 (67.1)	34.048	0.000
−0.9~-0.5%		573 (13.2)	201 (13.7)	81 (13.6)	103 (14.2)	188 (12.0)
≥-1.0%		946 (21.7)	276 (18.9)	133 (22.3)	208 (28.7)	329 (20.9)
Visit 2	4420	7.30 (6.53, 8.40)	6.45 (6.10, 6.80)	7.00 (6.60, 7.40)**	7.50 (7.00, 8.10)**	8.60 (8.00, 9.70)**	2911.657	0.000
Visit 3	3328	7.20 (6.50, 8.30)	6.40 (6.00, 6.80)	7.00 (6.60, 7.50)**	7.50 (7.10, 8.10)**	8.60 (8.00, 9.60)**	2248.103	0.000
Visit 4	2408	7.20 (6.50, 8.20)	6.50 (6.10, 6.80)	7.10 (6.70, 7.50)**	7.50 (7.10, 8.00)**	8.60 (7.90, 9.50)**	1586.085	0.000
Visit 5	1570	7.20 (6.50, 8.20)	6.50 (6.10, 6.70)	7.10 (6.70, 7.50)**	7.60 (7.23, 8.00)**	8.60 (8.00, 9.30)**	1041.278	0.000
Visit 6	967	7.10 (6.50, 7.90)	6.40 (6.00, 6.73)	7.10 (6.80, 7.50)**	7.50 (7.10, 8.20)**	8.60 (7.90, 9.20)**	633.442	0.000
Last visit	4690	7.40 (6.60, 8.50)	6.50 (6.10, 6.80)	7.20 (6.70, 7.60)**	7.60 (7.10, 8.20)**	8.70 (8.00, 9.70)**	3114.141	0.000

Notes: Data are numbers (%), medians (interquartile range (IQR)). Beginning with the second available HbA_1c measure: Group 1: ≥90% of HbA_1c measurements <7.5%; Group 2: 60~89% of HbA_1c measurements <7.5%; Group 3: 30~59% of HbA_1c measurements <7.5%; and Group 4: <30% of HbA_1c measurements <7.5%. ** P<0.01 vs group 1.

Figure 1 Four HbA_1c trajectories during the median of 2 years follow up in 4690 subjects with non-newly diagnosed Type 2 diabetes. Blue curve: group 1 with stable good glycaemic control; violet curve: group 2 with relative good glycaemic control; green curve: group 3 with moderate glycaemic control; red curve: group 4 with continuously poor glycaemic control.

Table 3 Multinomial Logistic Regression Analysis Results for the 3 Groups with Less Good HbA_1c Control

Variables	Group 2		Group 3		Group 4
	P value	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)
Diabetes duration (≥10 vs <10 years)	0.239	1.171 (0.900~1.523)	0.143	1.224 (0.934~1.604)	0.175	1.198 (0.923~1.555)
Education (below vs above high school)	0.002	1.514 (1.162~1.972)	0.097	1.258 (0.960~1.649)	0.226	1.175 (0.905~1.526)
Hypertension (yes vs no)	0.546	1.085 (0.832~1.416)	0.151	1.226 (0.929~1.619)	0.599	0.931 (0.713~1.215)
Retinopathy (yes vs no)	0.025	1.513 (1.052~2.175)	0.005	1.692 (1.171~2.445)	0.000	1.946 (1.367~2.770)
DKD (yes vs no)	0.769	1.067 (0.693~1.641)	0.252	1.282 (0.838~1.961)	0.543	1.137 (0.751~1.722)
Neuropathy (yes vs no)	0.803	0.967 (0.742~1.260)	0.247	0.850 (0.646~1.119)	0.200	1.190 (0.912~1.553)
BMI: no overweight/obesity		Reference		Reference		Reference
Overweight	0.914	1.023 (0.677~1.545)	0.962	0.990 (0.653~1.500)	0.450	1.168 (0.781~1.746)
Obesity	0.475	1.105 (0.840~1.455)	0.782	0.960 (0.721~1.279)	0.525	1.094 (0.829~1.445)
Baseline HbA1c (%)≤7.40		Reference		Reference		Reference
7.50~8.90	0.000	4.174 (2.752~6.331)	0.000	15.498 (10.244~23.445)	0.000	61.433 (41.034~91.973)
≥9.0	0.000	4.012 (2.099~7.669)	0.000	32.001 (17.504~58.505)	0.000	618.859 (337.237~1135.658)
HbA1c change from baseline to visit 1 (<-0.5%)			Reference		Reference
−0.9~-0.5%	0.045	0.661 (0.441~0.991)	0.000	0.443 (0.284~0.693)	0.000	0.156 (0.100~0.244)
≥-1.0%	0.000	0.370 (0.222~0.617)	0.000	0.181 (0.109~0.301)	0.000	0.022 (0.013~0.037)
Insulin usage (yes vs no)	0.000	1.909 (1.463~2.492)	0.000	2.297 (1.738~3.036)	0.000	2.901 (2.210~3.808)
Share-care (yes vs no)	0.204	1.191 (0.909~1.560)	0.379	0.882 (0.667~1.167)	0.178	0.830 (0.633~1.089)
Treatment adjustment (yes vs no)	0.435	1.108 (0.856~1.435)	0.029	1.348 (1.030~1.764)	0.024	1.348 (1.039~1.748)
Poor adherence to exercise (yes vs no)	0.410	1.142 (0.832~1.567)	0.301	1.187 (0.858~1.642)	0.036	1.392 (1.021~1.897)
Poor adherence to diet (yes vs no)	0.002	1.610 (1.187~2.184)	0.000	2.165 (1.589~2.951)	0.000	1.992 (1.476~2.688)
Poor adherence to medication (yes vs no)	0.897	1.036 (0.611~1.756)	0.357	0.769 (0.439~1.346)	0.996	1.001 (0.600~1.671)
Poor adherence to SMBG (yes vs no)	0.029	1.402 (1.035~1.900)	0.138	1.270 (0.926~1.740)	0.000	1.772 (1.309~2.398)
HbA1c measurements (<3 vs ≥3 per year)	0.037	0.762 (0.589~0.984)	0.002	1.551 (1.176~2.044)	0.002	1.530 (1.174~1.996)

Abbreviations: DKD, diabetic kidney disease; BMI, body mass index; %. HbA1c, haemoglobin A1c.