1. No category

Journal of Diabetology, October 2014; 3:1
http://www.journalofdiabetology.org/
Original Article:
Factors associated with change in glycemic control in Japanese patients:
Analyses of patients’ misperception
1
1,2
3
1
*T. Suzuki-Saito , Yokokawa H , Shimada K , Goto A , Yasumura S
1
Abstract
This study aimed at understanding the influence of misperception of glycemic control status on changes in
glycemic control after 1 year of the baseline survey among patients with poorly controlled diabetes and
examining the factors associated with improved glycemic control in patients with and without misperceptions.
Data on 190 Japanese patients with poorly controlled diabetes were collected from a hospital-based prospective
cohort study. Misperceptions of glycemic control and other medical information was collected from a selfadministered questionnaire and medical records at the baseline. Data on glycemic control was also obtained
from a 1-year follow-up survey. Patients with decreased HbA1c values were defined as improved and others as
unchanged or worsened. There was no significant relationship between misperceptions of glycemic control at
baseline and changes in glycemic control after 1 year. 41.1% of patients with improved glycemic control and 32.0
% with unchanged or worsened glycemic control had misperceptions at the baseline (p = 0.23). The factors
significantly associated with improved glycemic control were a self-perceived high score for a lifestyle regimen
adherence (odds ratio (OR) = 0.15, 95% confidence interval (CI) = 0.04–0.66) among patients with
misperceptions, as well as the presence of diabetes retinopathy (OR = 0.27, 95% CI = 0.10–0.73) among patients
without misperception. Although the misperception of glycemic control did not relate to the change in glycemic
control after 1 year, but the associated factors differed between the two groups. Evaluating misperceptions could
therefore assist health practitioners in providing suitable diabetes care.
Key words: Glycemic control, perception, diabetes management
1
Department of Public Health, Fukushima Medical
University School of Medicine, 1 Hikariga-oka,
Fukushima-shi, Fukushima 960-1295, Japan
2
Department of General Medicine, Juntendo
University School of Medicine, 2-1-1 Hongo,
Bunkyo-ku, Tokyo 113-8421, Japan
3
Ikenodai clinic, 3-1 Ikenodai,
Fukushima 963-8875, Japan
Koriyama-shi,
*Corresponding author:
(Current Details)
Tomoko Suzuki-Saito
Department of Public Health, Fukushima Medical
University School of Medicine, 1 Hikariga-oka,
Fukushima-shi, Fukushima 960-1295, Japan
E-mail: [email protected]
Introduction
Despite the various types of medications available
for the treatment of patients with diabetes, many
patients have glycosylated hemoglobin (HbA1c)
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values that do not meet the therapeutic target. One
study from Japan reported that more than 60% of
patients with diabetes did not meet the target
<6.9% set by the Japan Diabetes Society (JDS) (1).
Another study from an Asian region found that
nearly 80% of Malaysian patients did not achieve
the target of <7.0% (2). In addition to medication
therapy, proper self-management of diabetes by
patients themselves is an essential element of
successful diabetes management (3). The patient
empowerment approach is regarded as an effective
way to facilitate behavioral changes by encouraging
patients’ initiatives in diabetes care (3, 4). In the
empowerment approach which requires patients
with diabetes to make informed self-management
decisions, physicians and other health practitioners
should support patients by addressing their
psychosocial issues as well as their diabetic
condition so that patients can be aware of their
problems and take the initiative in their treatment
(3, 4).
In a previous report regarding diabetes patients'
self-perception of their glycemic control status, we
Journal of Diabetology, October 2014; 3:1
showed that 36% of patients with poorly controlled
type 2 diabetes mellitus at one hospital in Japan
misperceived their glycemic control as good (5). This
result suggested that misperception of glycemic
control among patients with poorly controlled
diabetes should be addressed in daily clinical
practice in addition to appropriate medication
therapy. Such a misperception can lead to
inappropriate self-management, which eventually
will hinder successful diabetes management. Some
cross-sectional reports have indicated that patients
with diabetes who did not misperceive their
glycemic control were more likely to have lower
HbA1c values than those who misperceived (6, 7).
Although various predictive factors of glycemic
control have been shown (8, 9), no report has
prospectively examined factors associated with
future glycemic control status focusing on patients’
misperception. It has also not been clarified if there
are any differences in factors associated with future
glycemic control having misperception or not.
Therefore, the aims of the present report were to (i)
clarify the factors associated with changes in
glycemic control after 1 year among patients with
poorly controlled diabetes, particularly focusing on
“misperception of glycemic control” and (ii) examine
the factors associated with the improvement of
glycemic control among each perception group
(with and without misperception).
Methods
This hospital-based prospective cohort study was
performed at the diabetes outpatient clinic of a
general hospital in Fukushima Prefecture, Japan. At
the time of this study, two physicians specializing in
diabetes care were working in this clinic. A baseline
survey was conducted from June to July 2009, and a
follow-up survey was conducted in August 2010.
Out of 649 patients who visited the diabetes clinic
during the baseline survey, 550 patients participated
in this study (84.7%). Enrollment rate i.e. 33 was
inaccessible owing to failures in the survey process
and 66 declined to participate. All study participants
completed a self-administered questionnaire during
their wait for clinical examination. Additionally, the
patients’ medical information was collected from
their medical records. Since the focus of this study
was on misperception regarding glycemic control
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among patients with type 2 diabetes who had
already received basic diabetes education, therefore
those with non-type 2 diabetes (n = 27) and those
who were newly diagnosed (n = 4) were excluded.
Consequently, 519 patients were enrolled in the
study analyses. A detailed description of the
baseline survey has been previously published (5). A
total of 508 patients who completed the
questionnaire about self-perception of glycemic
control at baseline were followed up. During the
follow-up survey, we reviewed the patients’ medical
records and obtained updated medical information
of the same month when patient participated in the
baseline survey. As we focused on “misperception”
case, data obtained from 190 patients who were
poorly controlled at the baseline survey were used
in this report. A detailed definition of
“misperception” will be provided.
The self-administrated questionnaire at baseline
included self-perception of glycemic control, selfperception of adherence to lifestyle and medical
regimens, depressive status, family support, lifestyle
items, family history and socio-demographic
background. Self-perception of glycemic control
was assessed by asking a single question: “To what
extent do you feel your diabetes is in control?” with
answers given on a Likert scale (1: poor to 4:
excellent) (10). This questionnaire was used in the
international collaborative study (10), and the
Japanese version that was developed by performing
the back-translation was applied in our previous
study (5). The reliability of this questionnaire was
confirmed by test-retest reliability (kappa coefficient
= 0.57). Self-perception of adherence to lifestyle
(diet and exercise) and medical (medication and
appointment keeping) regimens was scored from 1
(not at all) to 4 (very well) (10). Patient’s basic
medical information was also obtained in the
baseline survey. The variables collected in the
baseline survey were described in more detail in our
previous report (5).
During the follow-up survey, attendance at the
outpatient clinic was checked. For patients who
attended the clinic during the follow-up survey,
medical information including body weight, blood
pressure, and HbA1c (JDS) on the day of the visit
were obtained. All HbA1c (JDS) values were
converted to a National Glycohemoglobin
Journal of Diabetology, October 2014; 3:1
Standardization Program (NGSP) equivalent value
using the following formula: HbA1c (NGSP) (%) =
1.02 × HbA1c (JDS) (%) + 0.25% (11). Highperformance liquid chromatography was used to
measure HbA1c. In addition, the International
Federation of Clinical Chemistry and Laboratory
Medicine (IFCC) values were reported. The following
formula was used to convert NGSP values to IFCC
values: IFCC (mmol/mol) = 10.93 × HbA1c (NGSP)
(%) – 23.52 (mmol/mol) (12). The change in glycemic
control was assessed by subtracting HbA1c values at
the baseline surveys from HbA1c values at follow-up
surveys. Patients whose difference in HbA1c values
was less than zero were defined as “improved” while
those whose difference in HbA1c value was zero or
more were defined as “unchanged or worsened”.
In order to define “misperception of glycemic
control”, we first divided the patients into two
groups according to their baseline HbA1c values:
poorly controlled (HbA1c ≥ 7.4%, 57.4 mmol/mol)
and well controlled (HbA1c < 7.4%, 57.4 mmol/mol).
This cutoff value was set according to the JDS
clinical guideline, where an HbA1c value of 7.4–8.3
(57.4–67.2 mmol/mol) represents “not good” control
status and an HbA1c value of ≥8.4 (68.3 mmol/mol)
represents “poor” control status. This classification
was adopted in our previous report (5, 13). Although
the Japan Diabetes Society had adopted revised
clinical goals for diabetes therapy in June 2013 (3),
we used the same criteria that had been used at the
time of our baseline survey. We then dichotomized
self-perception scores for diabetic control into
“perceived as good” (patients who rated 3 or 4 on a
scale of 1–4) and “perceived as not good” (those
who rated 1 or 2). By using these two indicators, we
classified the patients with poorly controlled
diabetes who perceived their own glycemic control
to be good to the “with misperception group”. In
contrast, the patients with poorly controlled
diabetes who appropriately perceived their glycemic
control as not good were classified to the “without
misperception group”. In this study, the “with
misperception group” was defined only among the
patients with poorly controlled diabetes and
included patients who could not either recall or
interpret their glycemic control correctly.
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The research protocol was approved by the ethics
committees of Fukushima Medical University
(approval date: April 2, 2009; Application No. 817)
and the survey site hospital (approval date: April 21,
2009). All patients gave written informed consent to
participate in the study.
Statistical analysis
The chi-square test and Mann–Whitney U test were
performed to examine patient characteristics
according to 1-year changes in glycemic control,
especially focusing on the relationship between the
patients’ misperception and changes in glycemic
control. To examine the factors associated with the
improvement of glycemic control for both groups
(with misperception and without misperception), a
univariate analysis was performed for each item in
the first step. Then, the odds ratio (OR) for each
item was calculated using a logistic regression
model adjusted for only age, sex, and baseline
HbA1c value, which were considered basic items
associated with glycemic control. Multiple logistic
regression analysis was not performed owing to the
limited number of patients. A p value of <0.05 was
considered statistically significant. All analyses were
performed using SPSS Statistics 17.0 for Windows
(SPSS Inc., Chicago, IL, USA).
Results
Of the original 190 patients, we were unable to
follow up on 25. Therefore, 165 patients were
included in the analysis (follow-up rate of 86.8%).
The overall follow-up rate did not differ significantly
between the groups with and without misperception
(88.4% and 86.0%, respectively). The reasons for
losses to follow-up were as follows: in the group
without misperception, two patients died, one was
admitted to the hospital, eight dropped out, and six
were transferred to other hospitals whereas in the
group with misperception, one patient died, two
were admitted to the hospital, and five were
transferred to other hospitals.
Journal of Diabetology, October 2014; 3:1
http://www.journalofdiabetology.org/
Table 1: Differences in baseline characteristics of patients according to changes in glycemic control
after 1 year.
N (%) † or median (range)
Baseline characteristics
Age (≥65 years)
Sex (female)
Anthropometric measurements
2
Body mass index (kg/m )
Change in body weight over 1 year (decreased)
Systolic blood pressure (mmHg)
Diastolic blood pressure (mmHg)
Medication for hypertension (yes)
Medication for dyslipidemia (yes)
Family history of diabetes mellitus (present)
Diabetes-related factors
Fasting blood glucose (mg/dl)
HbA1c (NGSP) (%) §
HbA1c (IFCC) (mmol/mol) ¶
Duration of diabetes (years)
Treatment of diabetes
Diet and exercise only
Oral hypoglycemic agents
Insulin only or combination
Number of oral antidiabetic agents (≥2 drugs)
Diabetes complication (present)
Chronic kidney disease
Diabetic retinopathy
Diabetic neuropathy
Misperception of glycemic control (present)
Adherence to lifestyle regimen
Adherence to medical regimen
Lifestyle score (7–6) ††
Occupation (inoccupation)
Cohabitation (living with family)
Family support (high)
Food preparation (not self-performed)
Depression scale (positive)
Improved
Unchanged or worsened
p value ‡
(n = 90)
50 (55.6)
39 (43.3)
(n = 75)
33 (44.0)
37 (49.3)
0.14
0.44
23.8 (17.0–42.6)
44 (48.9)
127 (98–160)
70 (54–92)
52 (57.8)
35 (38.9)
52 (57.8)
24.4 (15.8–44.1)
29 (38.7)
132 (100–220)
74 (56–100)
40 (53.3)
31 (41.3)
41 (54.7)
0.59
0.19
0.13
0.11
0.57
0.75
0.69
157 (73–350)
8.2 (7.4–11.8)
66.1 (57.4-105.5)
12 (1–45)
146 (69–340)
7.9 (7.4–10.2)
62.8 (57.4-88.0)
10 (2–33)
0.72
0.02
2 (2.2)
59 (65.6)
29 (32.2)
52 (88.1)
0 (0.0)
55 (73.3)
20 (26.7)
51 (92.7)
21 (23.3)
19 (22.4)
29 (33.0)
37 (41.1)
2.5 (1.0–4.0)
4.0 (2.0–4.0)
24 (27.3)
51 (56.7)
86 (95.6)
40 (44.4)
54 (60.7)
25 (27.8)
15 (20.0)
29 (39.2)
18 (24.3)
24 (32.0)
2.5 (1.0–4.0)
4.0 (1.5–4.0)
18 (24.7)
41 (54.7)
66 (88.0)
29 (38.7)
37 (51.4)
23 (30.7)
†Percentage of each item was calculated excluding missing data. ‡Chi-square and Mann-Whitney U test.
§HbA1c (NGSP) was calculated by the following formula: HbA1c (NGSP) (%) = 1.02 × HbA1c (JDS) (%) + 0.25%.
¶HbA1c (IFCC) was calculated by the following formula: IFCC (mmol/mol) = 10.93 × HbA1c (NGSP) (%) – 23.52
(mmol/mol).
††Lifestyle score consisted of 7 items. Each favorable lifestyle was scored as 1: physical activity (≥2 times a week),
breakfast (every morning), snacks between meals (no), alcohol consumption (non-drinker), tobacco smoking (non2
smoker), sleeping hours (7–8), and BMI (18.5–24.9 kg/m ).
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0.15
0.29
0.41
0.61
0.03
0.23
0.23
0.45
0.15
0.70
0.80
0.13
0.45
0.24
0.68
Journal of Diabetology, October 2014; 3:1
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Table 2: The baseline characteristics of the with and without misperception groups
N (%) †or median (range)
With
Without
misperception
misperception
Baseline characteristics
Age (≥65 years)
Sex (female)
Anthropometric measurements
2
Body mass index (kg/m )
Change in body weight over 1 year (decreased)
Systolic blood pressure (mmHg)
Diastolic blood pressure (mmHg)
Medication for hypertension (yes)
Medication for dyslipidemia (yes)
Family history of diabetes mellitus (present)
Diabetes-related factors
Fasting blood glucose (mg/dL)
HbA1c (NGSP) (%) §
HbA1c (IFCC) (mmol/mol) ¶
Duration of diabetes (years)
Treatment of diabetes
Diet and exercise only
Oral hypoglycemic agents
Insulin only or combination
Number of oral antidiabetic agents (≥2 drugs)
Diabetes complication (present)
Chronic kidney disease
Diabetic retinopathy
Diabetic neuropathy
Adherence to lifestyle regimen
Adherence to medical regimen
Lifestyle score (7–6) ††
Occupation (inoccupation)
Cohabitation (living with family)
Family support (high)
Food preparation (not self-performed)
Depression scale (positive)
(n = 61)
45 (73.8)
31 (50.8)
(n = 104)
38 (36.5)
45 (43.3)
p value ‡
<0.001
0.35
23.5 (15.8–35.1)
32 (52.5)
134 (100–172)
70 (54–92)
37 (60.7)
23 (37.7)
31 (50.8)
24.6 (17.0–44.1)
41 (39.4)
124 (98–220)
70 (58–100)
55 (52.9)
43 (41.3)
62 (59.6)
0.06
0.10
0.009
0.67
0.33
0.65
0.27
161 (73–274)
8.0 (7.4–10.5)
63.9 (57.4–91.2)
13 (1–45)
147 (69–350)
8.1 (7.4–11.8)
65.0 (57.4–105.5)
9 (1–34)
0.71
0.29
0.002
1 ( 1.6)
39 (63.9)
21 (34.4)
32 (82.1)
1 ( 1.0)
75 (72.1)
28 (26.9)
71 (94.7)
0.03
15 (24.6)
18 (31.0)
14 (23.0)
3.0 (1.5–4.0)
4.0 (2.5–4.0)
22 (36.7)
45 (73.8)
59 (96.7)
37 (60.7)
34 (56.7)
14 (23.0)
21 (20.2)
30 (29.7)
33 (32.7)
2.5 (1.0–4.0)
4.0 (1.5–4.0)
20 (19.8)
47 (45.2)
93 (89.4)
32 (30.8)
57 (56.4)
34 (32.7)
0.51
0.86
0.19
<0.001
0.03
0.02
<0.001
0.09
<0.001
0.98
0.18
†Percentage of each item was calculated excluding missing data.
‡Chi-square test and Mann-Whitney U test.
§HbA1c (NGSP) value was calculated by the following formula: HbA1c (NGSP) (%) = 1.02 × HbA1c (JDS) (%) + 0.25%.
¶HbA1c (IFCC) value was calculated by the following formula: IFCC (mmol/mol) = 10.93 × HbA1c (NGSP) (%) – 23.52
(mmol/mol).
††Lifestyle score consisted of 7 items. Each favorable lifestyle was scored as 1: physical activity (≥2 times a week),
breakfast (every morning), snacks between meals (no), alcohol consumption (non-drinker), tobacco smoking (non2
smoker), sleeping hours (7–8), and BMI (18.5–24.9 kg/m ).
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Journal of Diabetology, October 2014; 3:1
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Table 3: Factors associated with the improvement of glycemic control in the follow-up survey: Patients with misperception
N(%)† or median (range)
Variables
Age (≥ 65 years)
Sex (female)
2
Body mass index (kg/m )
Change in body weight over 1 year (decreased)
Medication for hypertension (yes)
Medication for dyslipidemia (yes)
Family history of diabetes mellitus (present)
HbA1c (NGSP) (%)
HbA1c (IFCC) (mmol/mol)
Duration of diabetes (years)
Diet and exercise only
Oral hypoglycemic agents
Insulin only or combination
Number of oral antidiabetic agents (≥2 drugs)
Chronic kidney disease
Diabetic retinopathy
Diabetic neuropathy
Adherence to lifestyle regimen (>3)
Adherence to medical regimen (=4)
Lifestyle score (7–6)
Occupation (inoccupation)
Cohabitation (living with family)
Family support (high)
Food preparation (not self-performed)
Depression scale (positive)
Improved
(n = 37)
28 (75.7)
15 (40.5)
23.3 (18.9-35.1)
20 (54.1)
20 (54.1)
12 (32.4)
20 (54.1)
8.0 (7.4-10.5)
63.9 (57.4-91.2)
13 (1-45)
1 ( 2.7)
23 (62.2)
13 (35.1)
19 (82.6)
10 (27.0)
10 (29.4)
9 (24.3)
9 (25.7)
22 (68.8)
14 (37.8)
27 (73.0)
36 (97.3)
22 (59.5)
25 (67.6)
8 (21.6)
Unchanged or worsened
(n = 24)
17 (70.8)
16 (66.7)
23.9 (15.8-32.4)
12 (50.0)
17 (70.8)
11 (45.8)
11 (45.8)
7.8 (7.4-9.8)
61.7 (57.4-83.6)
13 (5-33)
0 ( 0.0)
16 (66.7)
8 (33.3)
13 (81.3)
5 (20.8)
8 (33.3)
5 (20.8)
12 (54.5)
22 (91.7)
8 (34.8)
18 (75.0)
23 (95.8)
15 (62.5)
9 (39.1)
6 (25.0)
†Percentage of each item was calculated excluding missing data.
‡Adjusted by age (categorized), sex, and HbA1c (NGSP) value at the baseline survey.
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Univariate
P-value
Adjusted Model‡
Odds ratio
95% CI
P-value
0.68
0.05
0.77
0.76
0.19
0.29
0.53
0.34
NA
NA
1.03
2.51
0.32
0.49
1.70
NA
NA
NA
(0.90- 1.19)
(0.70- 9.02)
(0.09- 1.10)
(0.16- 1.54)
(0.55- 5.20)
NA
NA
NA
0.64
0.16
0.07
0.22
0.35
NA
0.89
0.97
(0.91- 1.05)
0.45
0.95
0.82
(0.26- 2.58)
0.73
0.91
0.75
0.75
0.58
0.03
0.05
0.81
0.86
0.76
0.81
0.03
0.76
1.66
0.72
0.54
1.13
0.15
0.19
1.12
1.53
0.79
0.71
2.01
0.99
(0.27-10.30)
(0.18- 2.93)
(0.15- 1.97)
(0.30- 4.29)
(0.04- 0.66)
(0.04- 1.04)
(0.34- 3.69)
(0.24- 9.78)
(0.04-14.50)
(0.23- 2.20)
(0.47- 8.59)
(0.28- 3.56)
0.58
0.64
0.35
0.86
0.01
0.06
0.85
0.65
0.87
0.55
0.35
0.99
Journal of Diabetology, October 2014; 3:1
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Table 4: Factors associated with the improvement of glycemic control in the follow-up survey: Patients without misperception
(N(%)† or median (range))
Variables
Age (≥65 years)
Sex (female)
2
Body mass index (kg/m )
Change in body weight over 1 year (decreased)
Medication for hypertension (yes)
Medication for dyslipidemia (yes)
Family history of diabetes mellitus (present)
HbA1c (NGSP) (%)
HbA1c (IFCC) (mmol/mol)
Duration of diabetes (years)
Diet and exercise only
Oral hypoglycemic agents
Insulin only or combination
Number of oral antidiabetic agents (≥2 drugs)
Diabetes complication (present)
Chronic kidney disease
Diabetic retinopathy
Diabetic neuropathy
Adherence to lifestyle regimen (>3)
Adherence to medical regimen (=4)
Lifestyle score (7–6)
Occupation (inoccupation)
Cohabitation (living with family)
Family support (high)
Food preparation (not self-performed)
Depression scale (positive)
Improved
(n = 53)
Unchanged or worsened
(n = 51)
22 (41.5)
24 (45.3)
24.3 (17.0-42.6)
24 (45.3)
32 (60.4)
23 (43.4)
32 (60.4)
8.3 (7.4-11.8)
67.2 (57.4-105.5)
11 (1-34)
1 ( 1.9)
36 (67.9)
16 (30.2)
33 (91.7)
30 (60.0)
11 (20.8)
9 (17.6)
20 (39.2)
3( 6.0)
30 (58.8)
10 (19.6)
24 (45.3)
50 (94.3)
18 (34.0)
29 (55.8)
17 (32.1)
16 (31.4)
21 (41.2)
24.8 (18.9-44.1)
17 (33.3)
23 (45.1)
20 (39.2)
30 (58.8)
8.0 (7.4-10.2)
63.9 (57.4-88.0)
7 (2-31)
0 ( 0.0)
39 (76.5)
12 (23.5)
38 (97.4)
32 (64.0)
10 (19.6)
21 (42.0)
13 (26.0)
2( 4.3)
30 (65.2)
10 (20.0)
23 (45.1)
43 (84.3)
14 (27.5)
28 (57.1)
17 (33.3)
†Percentage of each item was calculated excluding missing data.
‡Adjusted by age (categorized), sex, and HbA1c (NGSP) value at the baseline survey.
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Univariate
Adjusted Model‡
P-value
Odds ratio
95% CI
P-value
0.28
0.67
0.92
0.21
0.12
0.67
0.87
<0.01
NA
NA
1.02
1.73
1.80
1.36
0.83
NA
NA
NA
(0.93- 1.11)
(0.73- 4.01)
(0.78- 4.12)
(0.58- 3.15)
(0.36- 1.95)
NA
NA
NA
0.71
0.21
0.17
0.48
0.68
NA
0.14
0.60
1.03
0.82
(0.97- 1.10)
(0.31- 2.18)
0.40
0.69
0.29
0.68
0.88
<0.01
0.16
0.70
0.52
0.96
0.99
0.11
0.47
0.89
0.89
0.20
(0.02- 2.17)
0.19
0.86
0.27
1.72
0.94
0.65
0.47
0.89
4.01
1.38
0.88
0.94
(0.30- 2.42)
(0.10- 0.73)
(0.67- 4.39)
(0.12- 7.50)
(0.27- 1.60)
(0.15- 1.51)
(0.35- 2.24)
(0.87-18.59)
(0.56- 3.40)
(0.31- 2.48)
(0.39- 2.28)
0.77
0.01
0.26
0.95
0.35
0.21
0.81
0.08
0.48
0.81
0.90
Journal of Diabetology, October 2014; 3:1
http://www.journalofdiabetology.org/
Differences in baseline characteristics of patients
according to changes in glycemic control after 1
year
improved HbA1c values were completely different
between
the
groups
with
and
without
misperception.
Among 165 patients, 90 patients experienced the
improvement in their HbA1c values (median of
difference was -0.7% with the range from -3.9% to 0.1%). The patients with improved HbA1c values
were more likely to have a higher HbA1c value and
less likely to have diabetic retinopathy at baseline
(Table 1). The proportion of patients with
misperception was 41.1% among those with
improved HbA1c and 32.0 % among those with
unchanged or worsened HbA1c values, and there
was no significant difference between these two
groups.
Contrary to our hypothesis, the patients’
misperception of glycemic control did not affect
negatively to their glycemic control status. This
unexpected result could be explained firstly, by the
presence of a small proportion of patients with
extremely high HbA1c levels among the present
patient population, thereby leading to slight
variations in HbA1c values. One previous study
reported
that
improvement
of
patients’
understanding of HbA1c led to an improvement in
HbA1c values, particularly among patients with very
poorly controlled diabetes (HbA1c > 9.0%) (14).
Secondly, our patients had rather a long duration of
disease and their perception and also the status of
disease control probably remained unchanged for a
long period of time before the study commenced,
leading to non-significant findings. Further,
examinations of newly diagnosed patients with a
larger sample size would be needed to confirm the
influence of patients’ misperception on their
glycemic control status.
Factors associated with improvement of glycemic
control in the follow-up survey according to
presence of misperception
The characteristics of patient with and without
misperception are shown in (Table 2) prior to
presenting the factors associated with improvement
of glycemic control. The proportion of the elderly
was particularly higher among the withmisperception group (73.8%) compared to the
without-misperception group (36.5%).
The results of the univariate and adjusted model
analyses for with and without misperception groups
are shown in (Tables 3 and 4) respectively. These
factors were found to vary significantly according to
the presence of misperception. Among the patients
with misperception (Table 3), those who gave
themselves a high score for adherence to a lifestyle
regimen were less likely to demonstrate improved
glycemic control (OR = 0.15, 95% CI = 0.04–0.66).
On the other hand, among patients without
misperception (Table 4), those with diabetic
retinopathy were less likely to improve their
glycemic control (OR = 0.27, 95% CI = 0.10–0.73).
Discussion
Following our previous report (5), this is the first
study in Japan to examine the change in glycemic
control among outpatients focusing on the
influence of patient’s misperception on HbA1c
values. Although misperception of glycemic control
did not influence the change in it in the present
study, we found that the associated factors of
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Page 8
Among the patients without misperception, the
presence of diabetic retinopathy at the baseline
survey was negatively associated with an
improvement in HbA1c values. Diabetic retinopathy
is known to be associated with poor glycemic
control and long disease duration (15). The capacity
to secrete β-cell insulin in patients with type 2
diabetes progressively declines even with proper
medication, eventually leading to impaired glycemic
control and diabetic complications (16, 17). It is
likely that the management of glycemic control was
more difficult among patients with diabetic
retinopathy than among patients without diabetic
retinopathy owing to declined endogenous insulin
secretion capacity. However this was not measured
in our study. Our findings indicate that the change
in glycemic control among patients without
misperception seemed to depend on the clinical
course of type 2 diabetes mellitus. This suggests
that conventional treatment for type 2 diabetes is
important for delaying the progression of the
disease.
Journal of Diabetology, October 2014; 3:1
On the other hand, patients with misperception
giving high ratings for their adherence to a lifestyle
regimen were paradoxically less likely to achieve
improved glycemic control status in our study,
although it is obvious that patients' high adherence
of a lifestyle regimen is an indispensable factor of
good glycemic control (3). A possible explanation
for this paradoxical result might be that patients
with poorly controlled diabetes with misperception
who gave a high score for adherence to their
lifestyle regimen overestimated their actual
adherence, consequently their lifestyle could not be
improved and their glycemic control did not change
or worsen. A previous study showed that patients
with diabetes who perceived their glycemic control
as good were more likely to overestimate their
physical activity and reported that perceiving
diabetes to be in good control leads a patient to
believe that he/she is managing the diabetes
correctly (18). Such a mechanism of overestimation
could be applied to our results. According to our
previous report, patients with misperception were
more likely to give higher evaluations of their
adherence to a lifestyle regimen than those without
misperception (5), which might indicate that
overestimation among patients with misperception
is a common problem to be addressed. Once a
patient’s misperception becomes evident in an
actual clinical setting, the health practitioner should
assess the patient’s adherence to a lifestyle regimen
based on the specific lifestyle information. Then, if
the patient still overestimates the level of adherence
to the lifestyle regimen, the health practitioner
should remind the patient of the overestimation and
support the patient to be able to evaluate his or her
own diabetes condition and self-management
behaviors correctly.
Limitations
There were some limitations to our study. First, the
patients who participated in this study were limited
to outpatients attending the diabetes clinic at the
survey site hospital, and very few patients were
included in the analysis of associated factors. Thus,
the generalizability of the results became limited.
Second, we analyzed the data without classifying the
patients by age group (e.g., the non-elderly and the
elderly) because of the limited sample size, although
the prevalence of patients with misperception and
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the characteristics of these patients differed
between the non-elderly and the elderly in our
previous study (5). In addition, detailed information
about changes in medication and history of
attendance at the clinic, which would also influence
glycemic control, was not included in our analyses.
Further study with a larger sample size and a
broader range of parameters is needed.
Conclusion
Although the misperception of glycemic control did
not affect glycemic control after 1 year, the
associated factors of improved HbA1c values
differed between the two perception groups (with
and without misperception). These results indicated
the possibility that detection of the patients’
misperception could be an effective clue for health
practitioners to provide diabetes care suitable to
patients’ understanding. In other words, for patients
with poorly controlled diabetes with misperception,
self-reported adherence to a lifestyle regimen
should be re-examined by their health practitioner
and improved to appropriate self-perception and
self-management behaviors.
Acknowledgements
We thank the staff of the Outpatient Department at
Hoshi General Hospital for cooperating with this
survey. The authors have no conflicts of interest to
declare.
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