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Original Article
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Possatorn Wongwutthiwet, M.D.* Tatree Bosittipichet, M.D.**, anakamon Leesri, Ph.D.***
*Bangkruai Hospital, Nontaburi 11130, ailand. **Department of Social Medicine, Phra Nakhon Si Ayutthaya Hospital, Phra Nakhon Si Ayutthaya
13000, ailand. ***Department of Community Health Nursing, Institute of Nursing, Suranaree University of Technology, Nakorn Ratchasima 30000,
ailand.
The Efcacy of Follow-up Phone Calls for
Capillary Blood Glucose Lowering in Diabetic
Patients in Primary Care Unit
ABSTRACT
Objective: To study the eect of telephone call intervention on glycemic control in diabetic patients for 2 months
Materials and Methods: e quasi-experimental research included 130 Patients from January 2020 to March
2020 in primary care. e 115 patients were divided into 2 groups through a simple randomization process, 61 in
experimental group and 54 in control group aer exclusion. 115 Patients will be tested for Capillary blood glucose
(CBG) level at a period of 0-month, 1-month and 2-months. CBG level were presented in mean ± SD, mean dierence
± SD and analyzed by Independent t-test and Paired t-test.
Results: e phone call intervention can lower CBG level compared to the control group. Mean dierence of CBG
between 0 month and 2 months follow-up in phone calls group vs control group (-6.80 ± 4.86 vs -2.96 ± 4.82 mg/dL)
and mean dierence CBG level between 1 month and 2 months follow-up in phone calls group vs control group
(-5.77 ± 4.09 vs -4.22 ± 5.10 mg/dL) but had no signicant dierence (p >0.05)
Conclusion: e follow-up phone calls can lower CBG level in the experimental group more than the control group,
but there is no signicant dierence.
Keywords: Diabetes mellitus type 2; phone call; glycemic control (Siriraj Med J 2021; 73: 801-807)
Corresponding author: anakamon Leesri
E-mail: thanakamon@sut.ac.th
Received 18 May 2021 Revised 2 September 2021 Accepted 21 September 2021
ORCID ID: https://orcid.org/0000-0003-2841-5729
http://dx.doi.org/10.33192/Smj.2021.104
INTRODUCTION
It is expected that ailand will completely enter an
aging society by 2022, and elderly people will account for
20 percent of all ai population.
1
Non-communicable
diseases (NCDs), such as diabetes and hypertension, would
be an inevitable case for an aging society. Diabetes
2
is a
condition that impairs the body cell’s ability to convert
sugar to energy which will be stored at liver, muscle
and fat. ese cause high blood sugar levels. Diabetes
is currently a crucial non-communicable disease, and
e World Health Organization (WHO) attaches great
importance to the promotion, prevention and control of
disease to avoid complications. In Western Pacic, it was
found that there were 162 million patients with diabetes
in 2019
3
, and ailand ranked fourth regionally, coming
aer China, Indonesia and Japan as there were 4.4 million
patients with diabetes found in ailand. According to
Health Data Center
4
under the Department of Public
Health, it was found that patients having well-controlled
diabetes made up for only 28.32 percent (while the target
proportion was 40 percent). In Nonthaburi Province,
there were 45,457 patients with diabetes whereas only
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12,252 of them had well-controlled diabetes, accounting
for 26.95 percent. In Bang Kruai District, there were 4,580
patients with diabetes whereas only 4,232 of them had
well-controlled diabetes, accounting for 26.03 percent.
In Bang Kruai Health Promoting Hospital, there were
401 patients with diabetes whereas only 100 of them had
well-controlled diabetes, accounting for 24.94 percent.
Without a good control of a blood sugar level, patients
can suer from the complications and premature death.
Comparing to the previous years, it is found that incidence
of diabetes increases in a wider age range. Furthermore,
according to the data from National Economic and Social
Development Board (NESDB) in 2008
5
, it was found
that in ailand, for Out Patients Department (OPD),
the average medical fee of diabetes was 1,173 Baht per
patient whereas for In Department Patients (IPD), the
average medical fee was 10,217 Baht per patient. e
total average medical fee was 3,984 million Baht per
year. Hence, if there are 3 million patients with diabetes
receiving medical service from healthcare centers, it will
cost 47,596 million Baht per year for medical fees.
Poor-controlled diabetes is caused by many reasons
such as patient’s lack of knowledge regarding of self-care
or lack of awareness in danger and severity of diabetes.
By these reasons, it results in discontinuity of medicine
taking, missing doctor’s appointments and inability to
adjust eating or exercising habits, and this can lead to
many complications such as chronic kidney disease
(CKD), Diabetic Retinopathy (DR), Diabetic Ulcer and
Cardiovascular Disease (CVD). ese complications
could worsen patient’s quality of life as well as nancial
burdens.
erefore, the researcher recognizes the signicance
of patient’s awareness, and many relevant studies also
indicate that many patients with diabetes lack a good
understanding of their conditions. The researcher,
hence, decides to study about the eect of follow-up
phone calls for glycemic control of diabetic patient.
Currently, there is an involvement of technology in a
medical treatment to enhance its eciency, and it is
found that the majority of people carry mobile phones
with them most of the time. is study is conducted to
provide guidance in giving care to patients with diabetes
and boosting patient’s awareness of the disease, and
this could encourage patients to adjust their habits and
control their sugar blood level better. Furthermore, it
could reduce patient’s risks of having complications
and enhance their living standards. It could also reduce
expenses given by patients for receiving medical service
and commuting to hospital, given by family to provide care
for patients, given by hospitals to treat several dierent
complications, and given by the nation to provide health
welfare to patients. Accordingly, the aims of this study
to investigate the ecacy of follow-up phone calls for
Capillary blood glucose lowering in diabetic patients in
primary care setting
MATERIALS AND METHODS
Study design & population
This study is quasi-experimental research with
two groups of samples, and there is an application of
Pretest-Posttest Design with nonequivalent groups. e
samples include 130 patients with diabetes who were 30
years old and older and continually received medical
service at Bang Kruai Health Promoting Hospital, Bang
Kruai District, Nonthaburi Province between January
2020 and March 2020. e Inclusion Criteria include
abilities in understanding ai language and using phones
as well as their voluntariness of consent to research.
e Exclusion Criteria are participant’s discontinuity
in receiving medical treatment according to doctor’s
appointment, their withdraw from the research and
ineligibility. Some participants might be found ineligible
later because they fail to meet inclusion criteria, and
this could result from participant’s mistakes in giving
information or researcher’s errors.
Study size
Study size was estimate from the study of phone call
intervention on glycemic control in diabetes patients.
6
e hypothesis is that patient’s HbA1c level decrease by
<7%. For the control group, it is 35.7%, while it is 60.9%
in the phone call intervention group (p value <0.001), this
is a two-sided experiment with type 1 error, signicance
at 5% and power at 80%. e sample size is calculated
to be 122 participants, and 5 percent is calculated added
in case of data loss. erefore, the population was 130
participants divided by simple randomization into 65
participants in each intervention group and a control
group.
Measurement and tools
Measurement in this study consisted of a patient’s
general data record, including gender, age, education level,
monthly income, chronic disease, height, weight, and
body mass index (BMI), as well as a record of patient’s
CBG level and blood pressure noted at starting point
(which will be referred as the 0 month) then one and
two-month aer that (or the 1 month and 2 months).
is e participants were instructed to fast up to 8 hours
before a blood test. is measurement was performed
the same in both intervention and control groups.
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e intervention group received follow-up phone
calls every two weeks, accounting for 4 times across
the whole study period. mean CBG of both the phone
calls and control groups were assessed and compared
at 0-month, 1 month and 2 months.
e follow-up call consists of a procedure for asking
about symptoms and details about taking medication.
Primary outcome was mean dierence of CBG
between 0-month, 1 month and 2 months and secondary
outcomes were mean CBG at 0-month, 1 month and
2 months, mean systolic and diastolic blood pressure
at 0-month, 1 month and 2 months, mean dierence of
systolic and diastolic blood pressure between 0-month,
1 month and 2 months.
Study Flow
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Data analysis
e data are analyzed by statistical analysis soware,
approved and recorded in a form of le by the following
statistical analysis soware: Patient’s general data are
presented in number (percentage), mean ± standard
deviation, median (inter quartile range), and the data
are analyzed by Chi-square test, Independent t-test,
Mann-Whitney U test. Patient’s data of blood sugar
level and blood pressure level (systolic and diastolic) are
presented in mean ± standard deviation, and the data
are analyzed by Independent t-test and Paired t-test.
Ethical statements
is study has been approved by the committee of
research ethics regarding to human study of Nonthaburi
Public Health Oce. (e number of projects: 2/2563,
certied at January 14, 2020).
RESULTS
Patient characteristics
A total of 115 diabetic patients between January
2020 and March 2020. 61 patients in phone call group
and 54 patients in control group. Table 1 provides the
demographic details and information of each group.
Aer comparing between the two study groups, beyond
the education level, there were no dierences found
related to patient characteristics and baseline clinical data
including mean HbA1C, mean systolic blood pressure,
mean diastolic blood pressure and mean LDL
TABLE 1. e general information of the sample size (N = 115).
Phone calls Control
n=61 n=54
p-value
Sex
Male 21 (34.4) 16 (29.6) 0.583
Female 40 (65.6) 38 (70.4)
Age (years old) 63.16±8.65 66.0±7.48 0.064
Educational Level
None 2 (3.3) 3 (5.6) < 0.05*
Pre-Primary School 9 (14.8) 20 (37.0)
Primary School 17 (27.9) 6 (11.1)
Pre-Secondary School 16 (26.2) 5 (9.3)
Secondary School 11 (18.0) 13 (24.1)
Bachelor degree 6 (9.8) 7 (13.0)
Income (bath) 2,500 (700, 6,500) 2,350 (700, 7,000) 0.772
Hypertension 54 (88.5) 44 (81.5) 0.288
Height (cm.) 158.89±7.33 159.52±8.06 0.660
Weight (kg.) 69.28±17.29 68.70±15.19 0.849
BMI (kg./m.
2
)
< 18.5 1 (1.6) 1 (1.6) 0.916
18.5 – 22.9 10 (16.4) 7 (13.0)
23.0 – 24.9 14 (23.0) 15 (27.8)
≥ 25 36 (59.0) 31 (57.4)
HbA1c (mg%) 7.83±1.48 7.45±1.29 0.940
Systolic blood pressure (mmHg) 141.16±18.54 144.26±16.59 0.350
Diastolic blood pressure (mmHg) 74.10±11.16 73.85±10.97 0.905
LDL (mg/dL) 106.64±33.73 110.17±33.83 0.577
*Chi-square test, Independent t-test, Mann-Whitney U test
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Capillary blood glucose level outcome
Table 2 e mean dierence of CBG between 0
month and 2 months in 2 groups showed that the mean
dierence of CBG in the phone calls group was greater
than in the control group with no signicance (-5.77±4.09
vs -4.22±5.10 P=0.812). Likewise, the mean dierence
of CBG between 0 month and 1 months in 2 groups
showed the same trend with no signicance (-6.80±4.86
vs -2.96.22±4.82 P=0.577) but the mean dierence of CBG
between 1 month and 2 months in 2 groups showed that
the mean dierence of CBG in the phone calls group was
less than in the control group (1.03±4.09 vs -1.26±5.10
P = 0.724).
Table 3 the mean CBG level at 0-month, 1-month
and 2-months in the phone calls group was less than in the
control group with no signicance (CBG M
0
144.49±33.54
vs 149.13±35.31 P= 0.472, CBG M
1
137.69±37.35 vs
146.17±37.59 P= 0.228, CBG M
2
138.72±32.66 vs
144.91±36.11, P= 0.337).
Systolic blood pressure (SBP) outcome
Table 2 e mean dierence of SBP between 0
month and 2 months in 2 groups showed that the mean
dierence of SBP in the phone calls group was lesser than
in the control group with no signicance (-9.33±1.64
vs -12.43±2.40 P=0.280). Likewise, the mean dierence
of SBP between 0 month and 1 months in 2 groups
showed the same trend with no signicance (-7.36±1.58
vs -11.44±2.55 P=0.166) but the mean dierence of CBG
between 1 month and 2 months in 2 groups showed that
the mean dierence of CBG in the phone calls group
was greater than in the control group (-1.97±1.48 vs
-0.98±2.04 P = 0.692).
Table 3 the mean SBP level at 0 month and 2 months
in the phone calls group was less than in the control group
with no signicance (SBP M
0
141.07±17.14 vs 144.50±16.49
P= 0.227, SBP M
2
131.74±14.23 vs 132.07±14.59, P=
0.901) and the mean SBP level at 1 month the phone calls
group was slightly greater than in the control group with
no signicance (SBP M
1
133.70±16.14 vs 133.06±13.55
P= 0.817)
Diastolic blood pressure (DBP) outcomes
Table 2 The mean difference of DBP between
0 month and 2 months in 2 groups showed that the mean
dierence of DBP in the phone calls group was greater
than in the control group with no signicance (-6.82±1.18
vs -5.91±1.43 P=0.622). Likewise, the mean dierence
of DBP between 0 month and 1 months in 2 groups
showed the same trend with no signicance (-3.57±1.16
vs -1.24±1.71 P=0.218) but the mean dierence of CBG
between 1 month and 2 months in 2 groups showed
that the mean dierence of CBG in the phone calls
group was lesser than in the control group (-3.07±1.03
vs -4.67±1.56 P = 0.383).
Table 3 the mean DBP level at 0 month in the
phone calls group was slightly greater than in the control
group with no signicance (DBP M
0
74.23±10.08 vs
TABLE 2. e comparation between Means of CBG level with blood pressure level (diastolic and systolic).
Phone calls Control
n=61 n=54
p-value
Mean Difference of CBG Level (mg/dL)
Month 0 and 1 -6.80±4.86 -2.96±4.82 0.577
Month 1 and 2 1.03±4.64 -1.26±4.45 0.724
Month 0 and 2 -5.77±4.09 -4.22±5.10 0.812
Systolic blood pressure (mmHg)
Month 0 and 1 -7.36±1.58 -11.44±2.55 0.166
Month 1 and 2 -1.97±1.48 -0.98±2.04 0.692
Month 0 and 2 -9.33±1.64 -12.43±2.40 0.280
Diastolic blood pressure (mmHg)
Month 0 and 1 -3.75±1.16 -1.24±1.71 0.218
Month 1 and 2 -3.07±1.03 -4.67±1.56 0.383
Month 0 and 2 -6.82±1.18 -5.91±1.43 0.622
* Analyzed by Independent t-test, Paired t-test
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TABLE 3. e comparison of CBG level with blood pressure level separated with systolic and diastolic blood pressure.
Phone calls Control
n=61 n=54
p-value
CBG Level (mg/dL)
0 month (CBG M
0
) 144.49±33.54 149.13±35.31 0.472
1 month (CBG M
1
) 137.69±37.35 146.17±37.59 0.228
2 months (CBG M
2
) 138.72±32.66 144.91±36.11 0.337
Systolic blood pressure (mmHg)
0 month (SBP M
0
) 141.07±17.14 144.50±16.49 0.227
1 month (SBP M
1
) 133.70±16.14 133.06±13.55 0.817
2 months (SBP M
2
) 131.74±14.23 132.07±14.59 0.901
Diastolic blood pressure (mmHg)
0 month (DBP M
0
) 74.23±10.08 74.19±11.13 0.982
1 month (DBP M
1
) 70.48±9.51 72.94±14.21 0.271
2 months (DBP M
2
) 67.41±9.13 68.28±10.70 0.640
74.19±11.13 P= 0.982) and the mean DBP level at 1
month and 2 months the phone calls group was lesser
than in the control group with no signicance (DBP M
1
70.48±9.51 vs 72.94±14.21 P= 0.271, DBP M
2
67.41±9.13
vs 68.28±10.70, P= 0.640)
DISCUSSION
Before the study, there was no dierence in the average
of blood sugar level (mg/DL) of phone calls and control
groups (p>0.05). However, when comparing the average
of blood sugar levels (mg/DL) recorded in the 0 month
and 1 month, it was found that the phone calls group’s
average blood sugar level decreased by a more substantial
amount than that of the control group (-6.80±4.86 vs
-2.96±4.82, p value = 0.577). Comparing the average of
blood sugar levels (mg/DL) in the 0
th
and 2
nd
months, it
was similarly found that the intervention group’s average
blood sugar level decreased by a more substantial amount
than that of the control group (-5.77±4.09 vs -4.22±5.10
p value = 0.812). erefore, it could be concluded that
there is clinical signicance of the intervention group
who received follow-up phone calls. is corresponds
with Naeti Suksomboon’s study
6
which conducted a
systematic review and meta-analysis of follow-up phone
calls as a way to control blood sugar levels, and it was
found that follow-up phone calls might not be more
eective in helping controlling blood sugar levels when
comparing to those who were not given follow-up phone
calls. However, it is still benecial for people living in
a country with small to medium incomes.
e reason why there was no statistical signicance
between two groups of the participants in the mentioned
study might be because of too small sample size, insucient
time of research, too short time of phone calls, insucient
information instructed to patients via phone calls, infrequent
phone calls or a lack of other media to follow up patients.
ese reasons might result in ineciency in controlling of
blood sugar levels. According to the study of Rattanaporn
Jeerawattana
7
, with motivation-promoting activities
and diabetes-instructing trainings before giving the
participants phone calls, it was found that the intervention
group’s average blood level decreased more signicantly
than that of the control group (11.43±1.92 vs 7.29±1.32
P<0.001). Likewise, according to Bogner’s study
8
, the
overall phone calls given to participants were two times,
and they lasted for 15 minutes, and this also included
three direct talks which lasted for 30 minutes, given
during three-month period. e ndings indicated that
the intervention group can control their blood sugar levels
more eectively than the control group do (Achieved
HbA1c <7%: 67 participants (60.9%) vs 25 participants
(35.7%), p value <.001).
Currently, technology plays a crucial role in
people’s life and most people are able to use phones for
communicative purposes. e researcher, therefore,
aims that this study could be guidance of how to provide
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more eective treatments to patients. Nevertheless, there
are some limitations including insucient samples and
limited time for phone calls. Also, three-month period for
follow-up might be insucient, so the ndings indicate
no statistical signicance. is study covers patients
from only one medical center, so it might not be able
to represent overall populations. However, since the
ndings illustrate that the intervention group has a more
ecient control of blood sugar levels than the control
group, the researcher would suggest that there should
be an increase of study populations, areas and time
period. Also, there should be some adjustments of the
directions for follow-up phone calls, such as an increase
in contents or time period. is would help follow-up
phone calls to work more eectively.
CONCLUSION
is quasi-experimental study’s results show that
follow-up phone calls can assist patients with diabetes
to control their blood sugar levels more eectively than
the control group, but there is no statistical signicance.
Further studies may be needed for more explicit data.
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