Long-term quality-of-care score for predicting the occurrence of acute myocardial infarction in patients with type 2 diabetes mellitus

Table 1 Quality-of-care scoring system

Item	Score
HbA1c
HbA1c measurement < 2/yr & HbA1c ≥ 8% (64 mmol/mol)	0
HbA1c measurement < 2/yr & HbA1c < 8% (64 mmol/mol)	1
HbA1c measurement ≥ 2/yr & HbA1c ≥ 8% (64 mmol/mol)	1
HbA1c measurement ≥ 2/yr & HbA1c < 8% (64 mmol/mol)	2
Blood pressure
Co-morbidity of hypertension, never used anti- hypertension agents	0
SBP ≥ 130 mmHg or DBP ≥ 80 mmHg, never used anti-hypertension agents	0
No blood pressure data, ever used anti-hypertension agents	0
SBP ≥ 130 mmHg or DBP ≥ 80 mmHg, ever used anti-hypertension agents	0
No blood pressure data, no co-morbidity of hypertension, and never used anti-hypertension agents	1
SBP < 130 mmHg and DBP < 80 mmHg	1
Lipid profile
Lipid profile measurement < 1/yr & LDL cholesterol ≥ 100	0
Lipid profile measurement < 1/yr & LDL cholesterol < 100	1
Lipid profile measurement ≥ 1/yr & LDL cholesterol ≥ 100	1
Lipid profile measurement ≥ 1/yr & LDL cholesterol < 100	2
Eye exam
Eye measurement < 1/yr	0
Eye measurement ≥ 1/yr	1
Foot exam
Foot exam < 1/yr	0
Foot exam ≥ 1/yr	1
Urine exam
Urine exam < 1/yr	0
Urine exam ≥ 1/yr	1

HbA1c: Hemoglobin; SBP: Systolic blood pressure; DBP: Diastolic bold pressure; LDL: Low density lipoprotein.

Table 2 Characteristics of quality-of-care score of patients with type 2 diabetes mellitus

	n (%)				P value
	Total, n = 7351	Score ≤ 1, n = 3858	1 < score < 5, n = 2819	Score ≥ 5, n = 674
Age (mean ± SD)	55.96 ± 11.94	57.08 ± 12.70	54.99 ± 10.94	53.62 ± 10.70	< 0.0001
≤ 40	643 (8.8)	330 (8.6)	245 (8.7)	68 (10.1)	< 0.0001
40 < age ≤ 65	4886 (66.5)	2369 (61.4)	2022 (71.7)	495 (73.4)
> 65	1822 (24.8)	1159 (30.0)	552 (19.6)	111 (16.5)
Sex
Male	3963 (53.9)	2146 (55.6)	1477 (52.4)	340 (50.5)	< 0.01
Female	3388 (46.1)	1712 (44.4)	1342 (47.6)	334 (49.6)
Duration of diabetes mellitus (mean ± SD)	9.95 ± 1.94	9.76 ± 2.06	10.14 ± 1.81	10.32 ± 1.60	< 0.0001
≤ 5 yr	216 (2.9)	161 (4.2)	52 (1.8)	3 (0.5)	< 0.0001
> 5 yr	7135 (97.1)	3697 (95.8)	2767 (98.2)	671 (99.6)
Anti-diabetic drugs
Oral only	4729 (64.3)	2483 (64.4)	1818 (64.5)	428 (63.5)	< 0.0001
Insulin only	1607 (21.9)	919 (23.8)	608 (21.6)	80 (11.9)
Oral + insulin	1015 (13.8)	456 (11.8)	393 (13.9)	166 (24.6)
Adherence to medication (%)
< 90	5340 (72.6)	3087 (80.0)	1872 (66.4)	381 (56.5)	< 0.0001
90 ≤ adherence < 110	1698 (23.1)	637 (16.5)	786 (27.9)	275 (40.8)
≥ 110	313 (4.3)	134 (3.5)	161 (5.7)	18 (2.7)
Comorbidity (DCSI)
0	4904 (66.7)	2444 (63.4)	1951 (69.2)	509 (75.5)	< 0.0001
1	1160 (15.8)	634 (16.4)	436 (15.5)	90 (13.4)
2	911 (12.4)	546 (14.2)	313 (11.1)	52 (7.7)
3	227 (3.1)	131 (3.4)	82 (2.9)	14 (2.1)
4	122 (1.7)	80 (2.1)	34 (1.2)	8 (1.2)
≥ 5	27 (0.4)	23 (0.6)	3 (0.1)	1 (0.2)
Hypertension/dyslipidemia
None	4782 (65.1)	2458 (63.7)	1845 (65.5)	479 (71.1)	< 0.0001
Hypertension only	1861 (25.3)	1054 (27.3)	669 (23.7)	138 (20.5)
Dyslipidemia only	265 (3.6)	124 (3.2)	118 (4.2)	23 (3.4)
Both	443 (6.0)	222 (5.8)	187 (6.6)	34 (5.0)
Acute myocardial infarction event
No	7043 (95.8)	3666 (95.0)	2716 (96.4)	661 (98.1)	< 0.001
Yes	308 (4.2)	192 (5.0)	103 (3.7)	13 (1.9)
Incidence rate (per 1000 person-year)	4.21	5.1	3.6	1.87

DCSI: Diabetes complications severity index.

Table 3 Crude and adjusted hazard ratio associated with each predictor

Item	Crude HR (95%CI)	Adjusted HR (95%CI)
Quality-of-care score
Score ≤ 1	1	1
1 < Score < 5	0.69 (0.55-0.88)	0.71 (0.55-0.90)
Score ≥ 5	0.36 (0.20-0.63)	0.37 (0.21-0.66)
Age
≤ 40	1	1
40 < Age ≤ 65	1.93 (1.12-3.32)	1.90 (1.10-3.28)
> 65	2.64 (1.51-4.62)	2.48 (1.39-4.40)
Sex
Male	1	1
Female	0.57 (0.45-0.73)	0.53 (0.42-0.67)
Anti-diabetic drugs
Oral only	1	1
Insulin only	0.80 (0.60-1.07)	0.78 (0.59-1.05)
Oral + insulin	0.70 (0.49-1.01)	0.77 (0.54-1.11)
Adherence to medication (%)
< 90	0.89 (0.69-1.15)	0.79 (0.61-1.02)
90 ≤ adherence < 110	1	1
≥ 110	0.71 (0.37-1.37)	0.66 (0.34-1.28)
Comorbidity (DCSI)
0	1	1
1	1.13 (0.83-1.54)	0.95 (0.69-1.31)
2	1.31 (0.94-1.81)	1.02 (0.72-1.43)
3	1.27 (0.69-2.33)	0.96 (0.52-1.80)
4	1.56 (0.73-3.31)	1.07 (0.49-2.31)
≥ 5	1.04 (0.15-7.43)	0.66 (0.09-4.77)
Hypertension/dyslipidemia
None	1	1
Hypertension only	1.38 (1.07-1.78)	1.30 (0.99-1.71)
Dyslipidemia only	1.19 (0.64-2.18)	1.17 (0.64-2.17)
Both	1.89 (1.27-2.79)	1.82 (1.20-2.75)

HR: Hazard ratio; 95%CI: 95% confidence interval; DCSI: Diabetes complications severity index.

Table 4 Comparisons of the number and percentage in each score of study subjects group defined by old and new score systems

Score	Present study (n = 7351)			Score	Previous study1 (n = 7351)		Sensitivity analysis2 (n = 3433)
	n (%)	Crude HR	Adjusted HR		n (%)	Adjusted HR	n (%)	Adjusted HR
0	2107 (28.7)	1	1	0	6 (0.1)	1	969 (28.2)	1
1	1751 (23.8)	1.21 (0.91-1.61)	1.22 (0.92-1.63)	5	720 (9.8)	0.19 (0.03-1.46)	828 (24.1)	1.17 (0.77-1.76)
2	1355 (18.4)	0.97 (0.70-1.33)	0.98 (0.71-1.35)	10	1333 (18.1)	0.23 (0.03-1.69)	654 (19.1)	1.00 (0.63-1.58)
3	925(12.6)	0.56 (0.36-0.86)	0.57 (0.37-0.89)	15	1148 (15.6)	0.24 (0.03-1.78)	420 (12.2)	0.49 (0.25-0.98)
4	539 (7.3)	0.60 (0.36-1.02)	0.63 (0.37-1.07)	20	2932 (39.9)	0.27 (0.04-1.98)	249 (7.3)	0.62 (0.28-1.38)
5	343 (4.7)	0.59 (0.31-1.14)	0.63 (0.33-1.26)	25	857 (11.7)	0.18 (0.02-1.35)	173 (5.0)	0.49 (0.17-1.36)
6	228 (3.1)	0.27 (0.08-0.84)	0.26 (0.08-0.83)	30	344 (4.7)	0.20 (0.03-1.54)	97 (2.8)	0.00 (0.00-NA)
7-8	103 (1.4)	0.00 (0.00-4.23E266)	0.00 (0.00-1.57E265)	35-40	11 (0.2)	0.77 (0.05-12.47)	43 (1.3)	0.00 (0.00-NA)

¹De Berardis et al[27], 2008; Rossi et al[26], 2011.

²In order to compare the performance of our scoring system with that in the previous study, we used 5-point increments to assign the scores.

HR: Hazard ratio.