Effectiveness of behavioral change techniques employed in eHealth interventions designed to improve glycemic control in persons with poorly controlled type 2 diabetes: a systematic review and meta-analysis protocol
Kebede et al. Systematic Reviews
Effectiveness of behavioral change techniques employed in eHealth interventions designed to improve glycemic control in persons with poorly controlled type 2 diabetes: a systematic review and meta-analysis protocol
Mihiretu Kebede 0 1 2 3
Lara Christianson 1
Zohaib Khan 0 1 3 4
Thomas L. Heise 0 1 3
Claudia R. Pischke 0 3
0 Leibniz Institute for Prevention Research and Epidemiology - BIPS , Bremen , Germany
1 University of Bremen, Health Sciences , Grazer Strasse 2, D-28359 Bremen , Germany
2 University of Gondar, College of Medicine and Health Science, Institute of Public Health , Gondar , Ethiopia
3 Leibniz Institute for Prevention Research and Epidemiology - BIPS , Bremen , Germany
4 Khyber Medical University , Peshawar , Pakistan
Background: The incorporation of Behavioral Change Techniques (BCTs) in eHealth interventions for the management of non-communicable diseases (NCDs), such as type 2 diabetes mellitus (T2DM), might be a promising approach to improve clinical and behavioral outcomes of NCDs in the long run. This 3paper reports a protocol for a systematic review that aims to (a) identify the effects of individual BCTs in eHealth interventions for lowering glycated hemoglobin levels (HbA1c) and (b) investigate which additional intervention features (duration of intervention, tailoring, theory-base, and mode of delivery) affect levels of HbA1c in this population. The protocol follows the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015 guideline. Methods/design: To identify eligible studies, an extensive systematic database search (PubMed, Web of Science, and PsycINFO) using keywords will be conducted. This review will include randomized controlled trials examining the effects of eHealth interventions on HbA1c in persons with poorly controlled T2DM over a minimum follow-up period of 3 months. Relevant data will be extracted from the included studies using Microsoft Excel. The content of the interventions will be extracted from the description of interventions and will be classified according to the BCT taxonomy v1 tool. The quality of studies will be independently assessed by two reviewers using the Cochrane risk of bias tool. If the studies have adequate homogeneity, meta-analysis will be considered. The effect sizes of each BCT will be calculated using the random effect model. The quality of the synthesized evidence will be evaluated employing the Grading of the Recommendations Assessment, Development and Evaluation (GRADE) criteria. Discussion: This systematic review is one of the firsts to appraise the effectiveness of eHealth interventions employing BCTs which aimed at improving glycemic control in persons with poorly controlled T2DM. The review will aggregate the effect sizes of BCTs on HbA1c levels. The results may inform future eHealth interventions targeting poorly controlled T2DM populations. (Continued on next page)
(Continued from previous page)
Systematic review registration: PROSPERO CRD42016049940
Type 2 diabetes mellitus (T2DM) is a chronic metabolic
disorder characterized by an inability to produce and/or
utilize adequate amounts of the hormone insulin. This
results in an inadequate metabolism of glucose leading
to hyperglycemic conditions in the blood circulatory
]. Consistently, high blood sugar levels contribute
to an increased risk for developing serious complications
affecting the heart and blood vessels, eyes, kidneys,
nerves, and teeth [
]. Poor glycemic control in
persons with diagnosed T2DM is one of the major
challenges to effective diabetes management [
having a glycated hemoglobin (HbA1c) level of ≥ 7.0%
are classified as having poorly controlled T2DM [
Patients suffering from poorly controlled T2DM have a
higher risk of diabetic-related complications and
mortality as well as lower quality of life [
]. Effective diabetes
management, especially the management of poor
glycemic control, requires continuous monitoring of
blood glucose levels, strict adherence to glucose
lowering treatment regimens and lifestyle recommendations
regarding diet and physical activity [
to the American Diabetes Association (2016), persons
with T2DM are required to monitor their blood
glucose levels frequently (e.g., fasting, before/after meals)
], to engage in at least 150 min/week of moderate
aerobic physical activity spread over 2 to 3 days, avoiding
the consumption of sugary beverages and low-fat or
non-fat products with refined grains and added sugars is
Electronic Health (eHealth) interventions provide a
successful mechanism for engaging patients with T2DM
under chronic care [
]. They are integral in
supporting patients with T2DM in engaging in necessary
selfmanagement behaviors, such as regular blood glucose
monitoring and insulin administration. Furthermore,
behavioral counseling and information to increase
knowledge regarding the risks and consequences of the disease
can be effectively delivered to patients via eHealth
]. In general, participation in eHealth
interventions that combine behavioral counseling and
health education is associated with improvements in
disease-related clinical and behavioral outcomes [
However, there is a lack of research identifying the effects
of the active ingredients of these multi-component
interventions and their impact on changes in HbA1c levels in
persons with poorly controlled T2DM.
The behavioral change technique (BCT) taxonomy is a
comprehensive tool which helps researchers identify the
active ingredients of behavioral interventions [
contains 93 techniques to change behavior that are
hierarchically clustered into 16 groups. This tool can be
retrospectively applied to evaluate the contents of
interventions outlined in the published literature. Thus far,
two systematic reviews examined the effects of different
BCTs employed in eHealth interventions targeting
persons with poorly controlled T2DM [
systematic review analyzed the results of 13 RCTs and reported
that BCTs, such as “feedback on performance” (for
example, feedback on progress, feedback on action
planning, feedback on quizzes, and feedback on personalized
goal setting), providing information on consequences of
behavior, problem-solving, and self-monitoring of
behavior were associated with improvements in psychosocial
well-being in persons with T2DM (i.e., reductions in
depression and psychological distress) . In a second
review, Avery and colleagues (2015) identified successful
strategies for the modification of physical activity and
HbA1c-levels in this patient population. Two BCTs,
namely “prompting the review of behavioral goals” and
“providing information on where and when to perform
physical activity” were reported as effective in reducing
the mean HbA1c levels in persons with T2DM [
However, the results of our previous scoping review
identified that no systematic review is currently available
to investigate which BCTs are effective in lowering HbA1c
levels of persons with poorly controlled T2DM [
Therefore, this review aims to identify effective BCTs and
where possible to aggregate the effect sizes of BCTs across
This review will systematically identify and evaluate the
effectiveness of BCTs employed in eHealth interventions
aimed at improving glycemic control in persons with
poorly controlled T2DM.
The objectives of this systematic review are the following:
1. To investigate the effect of individual (or combined)
BCTs employed in eHealth interventions targeting
persons with poorly controlled T2DM on
2. To examine which additional intervention features
(duration of intervention, tailoring, theory-base, and
mode of delivery) may affect levels of HbA1c in
persons with poorly controlled T2DM
Methods and analysis
This protocol follows the PRISMA-P (Preferred
Reporting Items for Systematic review and Meta-Analysis
Protocols) 2015 guideline [
] (see Additional file 1).
This systematic review will identify the contents of the
interventions based on the latest version of BCT
]. In this review, only randomized controlled
trials (RCTs) published between 1990 and June 2017
with a minimum follow-up period of 3 months that
investigated the effects of eHealth interventions on patient
populations with poorly controlled T2DM will be
Furthermore, studies will be included if
Effects of eHealth interventions for the promotion of
behavioral change among poorly controlled type 2
diabetes populations are reported.
A change in mean HbA1c is reported as an outcome
in both intervention and control groups.
The results of the studies are published in English or
Articles not published in English or in German will be
excluded from the review, as well as commentaries,
short reports of interventions, letters to the editor, and
editorials. In addition, eHealth interventions with the
aim of improving knowledge and skills of health care
providers related to the management of the disease will
We will include studies with participants that are
diagnosed with type 2 diabetes and over the age of 18 years
and who have reported glycated hemoglobin (HbA1c)
levels of > 7.0%.
We will analyze all eHealth-related interventions
including mHealth (mobile Health), or other computer or
mobile interventions (delivered via personal digital assistant
(PDA), tablet, smartphone, games, web-based, apps), and
all forms of information and communication technology
(ICT)-based behavioral change interventions targeting
persons with poorly controlled T2DM. This will include
tailored or untailored interventions that aim to improve
blood glucose monitoring by enhancing behavioral change
for better self-management, physical activity, adherence to
medications, and/or diabetes knowledge through patient
education. Tailoring is defined as any education, feedback,
or communication provided which is based on the
interest, physiological, and behavioral condition of the
participating individuals [
Type of comparators
Non-eHealth interventions or usual care will be
considered as comparators.
The main outcome of interest in this review is the mean
difference in glycated hemoglobin (HbA1c) levels pre-/
An intensive search in a set of databases will be
conducted by the first author. Searches will be performed in
PubMed, ISI Web of Science (Science Citation Index),
and PsycINFO. We will search peer reviewed journal
articles published in English and German.
Relevant keywords that were identified during scoping,
such as “type 2 diabetes,” “diabetes type 2,” “eHealth,”
“telemedicine,” “telehealth,” “mHealth,” mobile health,
“web-based” “Internet,” “digital media,” “short message
service,” “text message,” “videogame,” and “health game”
will be used as keywords. In the PubMed search, the
phrase “Title/Abstract” will be connected with the
keywords to look for relevant articles based on their titles
and abstracts. The Boolean operators “AND” and “OR”
will be used to connect the keywords. Then the full texts
of the peer reviewed articles meeting our inclusion
criteria will be retrieved. The PubMed search strategy is
included in the supplementary material of this protocol
(see Additional file 2). The search strategy will be
modified to meet the requirements of the other databases.
All bibliographic data of our search results will be
transferred to EndNote X7 reference Information System
] so that duplicate records can be removed.
The online screening tool Covidence will be used to
import the set of de-duplicated citations and to manage the
title and abstract screening process.
Two reviewers (MK and CP) will independently screen
the titles and abstracts of the articles identified in the
electronic search. Articles which do not satisfy the
eligibility criteria will be removed. Full texts of the remaining
articles will be retrieved and screened, according to the
eligibility criteria, to identify articles to be included in
the final review. Reasons for exclusion of any articles will
be recorded. Bibliographies of the selected articles will
be hand searched to identify any relevant studies that
might not have been included. Results of both authors
will be compared in the presence of a third author. In
case of a disagreement, the decision of a third reviewer,
one of the co-authors, will be considered final.
To assess the quality of studies, the Cochrane
Collaboration’s tool for assessing risk of bias in randomized trials
will be used [
]. Studies will be evaluated against the
predefined criteria. Sequence generation, allocation
concealment, blinding of participants, personnel and
outcome assessors, incompleteness of outcome data,
selective outcome reporting, and other sources of bias
from each study will be assessed.
Extraction of data
An Excel data extraction form will be prepared by MK
(see Additional file 3). Data from studies will then be
extracted by MK and CP using the extraction format.
Discussion will be held in case of disagreements.
Information on the salient features of the included studies,
i.e., title, study setting (country, study population), year of
publication, sample size, type of intervention/s, outcome/s,
duration of follow-up, intervention period, intervention
effect, HbA1c changes (and p values), confidence intervals,
and the type of statistical analysis will be extracted from
the included articles. In addition, BCTs employed in the
interventions will be identified based on the description of
interventions provided in the articles. The BCTs of the
interventions will be independently be coded by two
reviewers (i.e., two of the authors of this protocol) who have
experience with using the most recent and comprehensive
BCT taxonomy [
]. In the event of any disagreements
between two authors at any stage of the review process (i.e.,
during the screening of titles and abstracts, quality
assessment, data extraction, coding using the BCT taxonomy), a
third author will be consulted, whose decision will be final.
The main outcome of interest of this review is the mean
difference in glycated hemoglobin (HbA1c) percentage
pre-/post-intervention and between intervention and
control or usual care groups.
Strategy for assessing the risk of bias in the individual studies
The risk of bias in the included studies will be assessed by
three reviewers (TLH, ZK, and LC), using the Cochrane
risk of bias tools for RCTs [
]. Based on this assessment
tool, studies will be rated as having a low, high or unclear
risk of bias. If two authors have disagreements, a third
author will be consulted for resolving the discrepancy to
Missing data handling mechanisms
Whenever there is a lack of information necessary for
this review, the authors will contact the corresponding
author of the respective article to request the relevant
data via email or phone calls. If there is no response
after two attempts to contact the corresponding author
(within a maximum of 1 month), the article will be
excluded from the quantitative synthesis. The reason for
the exclusion, along with the citation of the individual
article will be provided. However, the authors of the
review may still decide to include the article in the
narrative synthesis, should there be relevant information
included in the article.
Assessment of heterogeneity and data synthesis
Cochrane collaboration Review Manager Version 5.3 will
be used to analyze the data [
]. The difference in
effectiveness of type and number of BCTs on HbA1c will be
analyzed using Stata version 14. The effect sizes of
individual BCTs will be calculated in a moderator analysis
using the meta-regression model or random effect
model. Meta-analysis will only be performed if there is
sufficient homogeneity in outcomes between at least two
studies. For meta-analysis, the statistical heterogeneity
will be computed using the I-squared statistic and
evaluated against the Cochrane’s chi-square test using a 10%
significance level. Pooled effect size estimates with a 95%
confidence interval that measure the size of the
intervention effect across the studies will be calculated. If the
heterogeneity remains significant and meta-analysis is
not feasible, a narrative synthesis will be carried out
using the framework by Popay and colleagues [
narrative synthesis of all relevant studies will include
tables of the study and participants’ characteristics,
intervention components, settings that interventions were
implemented in, and mean change in HbA1c in both
control and intervention groups.
Sensitivity analysis based on study design and study
quality (i.e., studies having a low risk of bias will be
compared to studies having a high risk of bias based on
the Cochrane risk of bias tool) will be performed to
determine the robustness of the results. We will also
perform sensitivity analysis to evaluate whether the choice
of the statistical model (random effect vs. fixed effect)
affects the results.
To determine differential effects on HbA1c, subgroup
analyses by type (tailored vs. untailored, theory vs. not
theory-based) and duration of intervention, and mode of
delivery (apps, games, web-based, computer, and mobile
phone) will be performed.
The risk of bias will be assessed using the Cochrane tool
for assessing risk of bias [
]. The risk of meta-bias will
be assessed using funnel plots. Whenever there is no or
only minimal risk of bias, the studies will be
symmetrically distributed about the mean effect size. Whenever
there is a higher risk of bias, there will be symmetry at
the top of the funnel plot, a few studies in the middle
and more studies at the bottom of the funnel plot will
be missing [
Confidence in cumulative evidence
The quality of the synthesized evidence will be evaluated
using GRADE (Grading of the Recommendations
Assessment, Development and Evaluation) [
quality of evidence will be ranked as very low, low,
moderate, and high. Two reviewers (MK and CP) will
independently evaluate the quality of evidence utilizing the
GRADE profiler (GRADEpro) software .
Subsequently, data will be imported from RevMan 5, and
GRADEpro will be used to tabulate summary findings.
Behavior change interventions help persons with T2DM
improve self-management behaviors, adhere to
medications, follow specific dietary recommendations, and
increase physical activity [
]. Due to its
comprehensiveness and reliability, an increasing number of systematic
reviews are employing the BCT taxonomy to synthesize
evidence regarding active ingredients of behavioral
Currently, there is a lack of reviews aimed at assessing
the effectiveness of individual BCTs employed in eHealth
interventions aimed at improving glycemic control
among persons with poorly controlled T2DM. This
review will be one of the first to shed further light on
the question which BCTs are essential in eHealth
interventions designed to improve glycemic control.
Furthermore, results of this review may inform the development
of future interventions targeting this population.
Presentation and reporting of the results
This systematic review protocol will follow the
recommendations of the Preferred Reporting Items for
Systematic Review and Meta-Analysis Protocols 2015 Statement
Additional file 1: PRISMA-P 2015 checklist (DOC 100 kb)
Additional file 2: PubMed search strategy (DOC 34 kb)
Additional file 3: Data extraction template. (XLS 34 kb)
BCT: Behavioral Change Techniques; GRADE: Grading of the
Recommendations Assessment, Development and Evaluation;
HbA1c: Glycated hemoglobin; PRISMA: Preferred Reporting Items for
Systematic Review and Meta-Analysis; RCT: Randomized Controlled Trial;
T2DM: Type 2 diabetes mellitus
We would like to thank Prof. Dr. Hajo Zeeb for his support during the
development of this protocol.
No external funding has been received for this review.
Availability of data and materials
MK initiated the idea and wrote the first draft of the protocol. TLH, ZK, and
CP critically revised the draft of the protocol. MK and LC will conduct the
systematic electronic searches. TLH, ZK, and LC will conduct the quality
assessment of the included studies. MK, TLH and CP will extract and record
the data from the selected studies. MK will conduct the meta-, sensitivity,
and heterogeneity analyses. TLH, ZK and CP will review the results. All
authors substantially contributed in writing the protocol of this manuscript.
All authors read and approved the final version of this protocol.
Ethics approval and consent to participate
Consent for publication
The authors declare that they have no competing interests.
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