Does knowledge on diabetes management influence glycemic control? A nationwide study in patients with type 1 diabetes in Brazil

Figures & data

Figure 1 Six questions to evaluate knowledge on diabetes managment.

Notes: Patients were asked to answer all six questions.

Table 1 Socio-demographic, clinical, and diabetes knowledge characteristics of the study participants

Variable
N	1,760
Gender, female, n (%)	983 (55.9)
Age (years)	29.9±11.9
<19, n (%)	297 (16.9)
≥19, n (%)	1,463 (83.1)
Ethnicity, n (%)
Caucasians	959 (54.5)
Non-Caucasiansa	801 (45.5)
Economic status, n (%)
High	53 (3.0)
Medium	801 (45.5)
Low	849 (48.3)
Very low	57 (3.2)
Duration of diabetes (years)	15.5±9.3
Age of diagnosis (years)	14.7±8.9
Time of follow-up (years)	9.7±7.6
Insulin regimens, n (%)
Intermediate or long acting	86 (4.9)
Intermediate/long plus short acting	1,612 (91.6)
CSII	62 (3.5)
Insulin (IU/kg)	0.86±0.38
Knew what is the level of HbA1c considered as being good glycemic control,b n (%)	1,091 (62.0)
Do you perform SMBG daily? Yes, n (%)	1,663 (67.3)
Do you know why you need to perform SMBG? n (%)	1,672 (95.2)

Notes: Data are presented as numbers (percentage) or mean ± SD.

a African-Brazilians, Mulattos, Asians, and Native Indians.

b HbA1c at goal was defined as HbA1c <7.5% (58 mmol/mol) for T1D patients between 13 and 19 years and <7.0% (53 mmol/mol) for adult T1D patients.

Abbreviations: CSII, continuous subcutaneous insulin infusion; HbA1c, glycated hemoglobin; SMBG, self-monitoring of blood glucose; T1D, type 1 diabetes.

Table 2 Socio-demographic, clinical, and diabetes management data stratified according to the knowledge on what HbA1c means

Variable	Knowledge on HbA1c
	Yes	No	P-value
N (%)	1,190 (67.6)	570 (32.4)
Gender, female, n (%)	682 (57.3)	301 (52.8)	0.07
Age (years)	30.2±11.8	29.6±12.1	0.07
Age (years), n (%)			<0.001
<19	168 (14.1)	129 (22.5)
≥19	1,022 (85.9)	441 (77.4)
Years of study (years)	13.0±3.7	10.5±3.4	<0.001
Ethnicity, n (%)			<0.001
Caucasian	713 (60.0)	246 (43.2)
Non-Caucasiana	476 (40.0)	324 (56.8)
Economic status, n (%)			<0.001
High	46 (86.8)	7 (13.2)
Medium	637 (79.5)	164 (20.5)
Low	489 (57.6)	360 (42.4)
Very low	17 (29.8)	40 (70.2)
Duration of diabetes (years)	16.2±9.3	13.9±9.0	<0.001
Mean age at diagnosis (years)	14.1±8.7	15.9±9.2	<0.001
Time of follow-up (years)	10.1±7.7	8.5±8.7	<0.001
Diabetes treatment, n (%)			<0.001
Intermediate/long acting insulin	24 (27.6)	63 (72.4)
Intermediate- or long- and short-acting insulin	1,105 (68.6)	506 (31.5)
CSII	61 (98.4)	1 (1.6)
Glycemic control
HbA1cb (%), current	8.7±1.9	9.5±2.3	<0.001
HbA1c (mmol/mol)	71.6±2.7	80.3±1.6
HbA1c (%) reported by the patient	8.5±1.9
HbA1c (mmol/mol) reported by the patient	69.4±2.7
HbA1c (%), last year	8.9±2.9	9.6±2.6	<0.001
HbA1c (mmol/mol)	73.8±8.2	81.4±4.9
HbA1c (good), n (%)b	196 (16.6)	57 (10.3)	<0.001
HbA1c (poor), n (%)b	432 (36.6)	307 (55.2)
Hypoglycemia (severe), yes, n (%)	160 (17.0)	91 (23.9)	0.004
Diabetes management
SMBG, yes, n (%)	1,143 (68.7)	520 (31.3)	<0.001
SMBG, n	3.7±1.4	3.4±1.5	0.002
Adherence to insulin therapy,c yes, n (%)	95 (14.0)	71 (23.6)	0.01
Adherence to diet, yes, n (%)	669 (62.2)	234 (49.4)	0.001
Smoking status, yes, n (%)	39 (5.7)	20 (6.6)	0.5
BMI (kg/m^2)	24.3±4.1	23.9±4.2	0.1
Hospitalization,d yes, n (%)	105 (15.4)	59 (19.6)	0.1
Clinical visits, n	3.6±1.7	3.6±1.8	0.5
Appointments with nurse, n	2.5±1.4	2.5±1.9	0.9
Participation in diabetes educational programs, yes, n (%)	95 (14.0)	25 (8.3)	0.01

Notes: Data are presented as a percentage, mean ± SD.

a African-Brazilians, Mulattos, Asians, Native Indians;

b HbA1c at goal was defined as HbA1c <7.5% (58 mmol/mol) for T1D patients between 13 and 19 years and <7.0% (53 mmol/mol) for adult T1D patients. HbA1c >9.0% (75 mmol/mol) was defined as poor glycemic control.

c Adherence to insulin therapy was considered the maximum adherence according to Morisky-Green-Levin, patients using CSII were excluded.

d Hospitalization for any cause.

Abbreviations: BMI, body mass index; CSII, continuous subcutaneous insulin infusion; HbA1c, glycated hemoglobin; SMBG, self-monitoring of blood glucose; T1D, type 1 diabetes.

Table 3 Final adjusted logistic regression model with knowledge on what HbA1c means as the dependent variable

	N	β	OR	95% CI		P-value
Self-reported ethnicity, Caucasians, yes	725	0.57	1.76	1.35	2.29	<0.001
Economic status
High	43	0.67	3.379	1.00	12.4	0.06
Medium	635	0.44	3.633	1.55	8.53	0.003
Low	605	0.43	2.068	0.90	4.76	0.09
Very low	33					Reference
Severe hypoglycemia, yes	251	0.34	1.40	1.02	1.92	0.038
Years of study	1,316	0.18	1.20	1.15	1.25	0.001
Follow-up at each center (years)	1,316	0.02	1.03	1.01	1.04	0.001
Participation on educational diabetes program	170	0.94	2.56	1.60	4.11	0.002

Abbreviation: HbA1c, glycated hemoglobin.

Table 4 Final adjusted logistic regression model with patients with HbA1ca at goal as the dependent variableb

	N	β	OR	95% CI		P-value
Knowledge on HbA1c means	814	0.742	1.555	1.054	2.293	0.002
Adherence to diet, yes	358	0.441	2.43	1.718	3.436	0.001
Years of study	814	0.097	1.102	1.05	1.157	<0.001
Age (years)	814	0.014	1.014	1	1.028	0.047
SMBG, n	814	0.197	1.218	1.117	1.38	0.001

Notes:

a HbA1c at goal was defined as HbA1c <7.5% (58 mmol/mol) for T1D patients between 13 and 19 years and <7.0% (53 mmol/mol) for adult T1D patients.

b In this analysis, 814 patients were included (n=222 with HbA1c at goal and n=592 with HbA1c ≥9.0%).

Abbreviations: HbA1c, glycated hemoglobin; SMBG, self-monitoring of blood glucose; T1D, type 1 diabetes.