DIABETICMedicine
DOI: 10.1111/j.1464-5491.2012.03659.x
Review Article
Self-monitoring of blood glucose in patients with
diabetes who do not use insulin—are guidelines
evidence-based?
K. M. Aakre1,*, J. Watine2,*, P. S. Bunting3, S. Sandberg1,4 and W. P. Oosterhuis5,*
1
Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway, 2Laboratoire de Biologie Polyvalente, Hôpital de la Chartreuse, Villefranchede-Rouergue, France, 3Division of Biochemistry, The Ottawa Hospital, Ottawa, ON, Canada, 4The Norwegian Quality Improvement of Laboratory Services in
Primary Care (NOKLUS), Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway and 5Department of Clinical Chemistry,
Atrium Medical Centre, Heerlen, the Netherlands
Accepted 16 February 2012
Abstract
To evaluate if clinical practice guideline recommendations regarding self-monitoring of blood glucose in patients with
diabetes not using insulin follow the principles of evidence-based medicine.
Aims
Methods After a search from 1999 to 2011, 18 clinical practice guidelines were included. Recommendations regarding selfmonitoring of blood glucose were graded on a scale from one (strongly against self-monitoring) to four (strongly in favour of
self-monitoring) and compared with the similarly graded conclusions of systematic reviews that were cited by the clinical
practice guidelines. We also investigated how clinical practice guideline characteristics, for example funding sources, and
quality of references cited could be related to the guideline recommendations.
The clinical practice guidelines cited in total 15 systematic reviews, 14 randomized controlled trials, 33 nonrandomized controlled trials papers and 18 clinical practice guidelines or position statements. The clinical practice guideline
recommendations had an average grade of 3.4 (range 2.0–4.0). Higher grades were seen for clinical practice guidelines that
acknowledged industry funding (mean value 4.0) or were issued by organizations depending on private funding (mean value
3.6 vs. 3.0 for governmental funding). The conclusions of the 15 systematic reviews had a mean grade of 2.2 (range 1.0–3.8).
Systematic reviews with low grades were less cited. In total, 21 randomized controlled trials were included in the systematic
reviews. Approximately half of these evaluated an educational intervention where the effect of self-monitoring of blood
glucose could not be clearly isolated.
Results
Conclusions Clinical practice guidelines were more in favour of self-monitoring use than the systematic reviews that were
cited. The citation practice was non-systematic and industry funding seemingly led to a more positive attitude towards use of
self-monitoring of blood glucose.
Diabet. Med. 29, 1226–1236 (2012)
Introduction
The scientific literature and most healthcare professionals
agree that self-monitoring of blood glucose is useful in people
with diabetes who are using insulin [1,2]. In contrast, the use
of self-monitoring of blood glucose in people not treated with
insulin is controversial. Some recommend self-monitoring in
Correspondence to: Kristin Moberg Aakre.
E-mail: [email protected]
*Member of the European Federation of Clinical Chemistry and European
Union of Medical Specialists joint working group on Guidelines.
1226
all individuals with diabetes, others believe that the evidence
is too weak to support the use of such intervention in a
majority of those who do not use insulin [3,4]. The costs
related to self-monitoring are high and approximately half of
these expenditures are spent by patients who do not use
insulin [4,5].
Earlier studies have subjected clinical practice guidelines to
critical appraisal using, for example, the Appraisal of
Guidelines for Research and Evaluation (AGREE) instrument,
which assesses the guidelines scope ⁄ purpose, stakeholder
involvement, rigour of development, clarity, applicability and
editorial independence [6]. Low quality has been shown for a
large number of guidelines [7–9]. However, the AGREE
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
Review article
instrument does not explore in detail the link between the
recommendation given and evidence cited to justify this
recommendation.
Clinical practice guidelines following the principles of evidence-based medicine should use considered judgment in order
to combine the scientific evidence about both clinical benefits
and harms with clinicians’ experience, patients’ preferences and
the availability of resources [10]. The various guideline development teams may have different judgments, even if the
evidence examined is exactly the same. Different recommendations may be given without contradicting the principles of
evidence-based medicine. However, it should be very clear to
the reader how considered judgment was used in the guideline
development process and even more if the issued recommendation differs from the conclusions of the scientific evidence.
The aim of this study was to explore to what extent current
clinical practical guideline recommendations about use of selfmonitoring of blood glucose in patients with diabetes who do
not use insulin are based on the principles of evidence-based
medicine. Three topics are highlighted: (1) the link between the
recommendations given and the evidence cited to justify the
recommendation; (2) the use of considered judgement; (3) any
relation between different guideline characteristics and the
published recommendation. Quality of evidence was deemed to
be higher if systematic reviews were referenced in support of a
guideline recommendation and, if these were not available,
randomized controlled trials rather than non-randomized
studies.
Methods
The original search for clinical practice guidelines has been
described earlier [7]. Briefly, the time frame was from 1999 to
2007. PubMed, journals and guideline databases were searched
systematically. In 2011, an update of the search was performed
to include more recent publications and to ensure that the latest
update of all included guidelines were used. Inclusion criteria
were: availability, i.e. written in English and published in a
scientific journal or on the Web free of charge; and that the
guideline addressed the topic of self-monitoring of blood glucose in patients with diabetes not using insulin. Guidelines were
retrieved and considered for inclusion by two independent pairs
of reviewers (KMA ⁄ JW or WPO ⁄ PSB) and discrepancies on
inclusion were solved by discussion.
The clinical practice guidelines were reviewed and the
following characteristics were explored: description of the
guideline developing process including input from patients; if
strength of the evidence was denoted; discussion of cost–benefit
or quality-of-life issues; industry funding stated; type of organization issuing the guideline (i.e. depending on governmental
or private funding); use of considered judgement (i.e. if the
guideline very clearly and explicitly explained how scientific
evidence was combined with economic issues, patient
preference and clinical experience in development of the
recommendations). All citations that were related to the effect
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
DIABETICMedicine
of self-monitoring on glucose control in patients who were not
using insulin were identified and further categorized as systematic reviews, randomized controlled trials, non-randomized
primary studies, opinion or review articles and guidelines or
position statements. The systematic reviews were retrieved and
characteristics registered (i.e. different types of publications
included, if quality rating of included articles was performed
and acknowledgement of industry funding). The main characteristics of the randomized trials included in the different systematic reviews were evaluated (i.e. number of patient
included, methods, main results, authors conclusions, if the
design made it possible to isolate the effect of self-monitoring
from other interventions). Abstracts and publications dealing
with the effect of frequency of self-monitoring of blood glucose,
quality of instruments or tools related to self-monitoring
(logbooks, etc.) were excluded.
Grading of recommendations in guidelines and conclusion of
systematic reviews
The guideline recommendations, as well as the discussion and
conclusions of the systematic reviews for or against use of selfmonitoring of blood glucose were graded by three independent
reviewers (KMA, JW, WPO) according to a scale of 1–4:
grade 1, strongly against self-monitoring (in general not recommended based on an assumed overall absent or negative
effect in most patients); grade 2, weakly against self-monitoring
[in general not recommended (except in subgroups) because of
an assumed overall limited or uncertain effect]; grade 3, weakly
in favour of self-monitoring [in general recommended but
limitations stated (may only be used for limited time periods or
as part of a self-management programme)]; grade 4, strongly in
favour of self-monitoring (recommended based on an assumed
clinically relevant positive effect in most patients).
The grading of the clinical practice guidelines (mean values)
were stratified according to guideline characteristics. Further,
the mean grading of systematic reviews that were cited by a
guideline were compared with the mean grading of systematic
reviews that were published before the release of the guideline
but still not cited, using an independent Student’s t-test. Statistics
were performed using SPSS 18.0 (SPSS Inc., Chicago, IL, USA).
Results
In total, 33 guidelines were retrieved and considered for inclusion, and 18 fulfilled the inclusion criteria. Excluded guidelines
considered the use of self-monitoring of blood glucose in
patients with Type 1 diabetes, children, pregnancy or ethnic
minorities. In total, the included guidelines cited 15 systematic
reviews evaluating the effect of self-monitoring on glucose
control as well as 14 randomized trials, 30 non-randomized
primary papers, three review ⁄ opinion papers and 18 clinical
practice guidelines or position statements. All systematic reviews
and most randomized trials used the effect of self-monitoring on
HbA1c as the key outcome measured. Table 1 shows the
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Are self-monitoring of blood glucose recommendations evidence based? • K. M. Aakre et al.
DIABETICMedicine
Table 1 Guideline recommendations regarding self-monitoring of blood glucose in patients with Type 2 diabetes mellitus who are not using insulin
Guideline, year and
reference
Publications cited
Conclusion of clinical practice guideline
Grading*
International Diabetes
Federation, 2005 [2]
3
4
2
4
4
National Academy of
Clinical Biochemistry,
2006 [24]
3 systematic reviews
9 (8 ) randomized controlled trials
14 non-randomized controlled
trials
1 opinion ⁄ review papers
4 clinical practice guidelines
None
Standard care: self-monitoring of blood glucose
should be available for all newly diagnosed
people with Type 2 diabetes, as an integral part
of self-management education. Self-monitoring
should be considered on an ongoing basis for
people using oral agents and an intermittent
basis for those not using oral agents
The evidence is insufficient to recommend for or
against routinely using self-monitoring of
blood glucose
Self-monitoring of blood glucose should be
initiated in most patients with diabetes. Selfmonitoring is indicated for patients who are at
increased risk of developing hypoglycaemia
and ⁄ or are vulnerable to injury from
hypoglycaemia, and for all patients who have
failed to achieve glycaemic goals
Instruct patients who are meeting target glycaemic
levels (including those treated nonpharmacologically) to monitor glucose levels at
least once daily
Self-monitoring of blood glucose should be
considered because it is currently the most
practical method for monitoring post-meal
glycaemia. Self-monitoring frequency for people
who are not treated with insulin should be
individualized to each person‘s treatment
regimen and level of control
Self-monitoring of blood glucose should depend
on treatment modality and current diabetes
control as well as the patient’s physical, cognitive
and financial capabilities. Self-monitoring can be
beneficial for the older adult, but frequency of
monitoring is highly individualized
Offer self-monitoring of plasma glucose to a
person newly diagnosed with Type 2 diabetes
only as an integral part of his or her
self-management education. Self-monitoring
should be available; to those on oral glucoselowering medications; to assess changes in
glucose control resulting from medications and
lifestyle changes; to monitor changes during
intercurrent illness; to ensure safety during
activities, including driving
For individuals treated with oral antihyperglycaemic agents or lifestyle alone, the
frequency of self-monitoring of blood glucose
should be individualized, depending on
glycaemic control and type of therapy, and
should include both pre- and postprandial
measurements
Self-monitoring of blood glucose can be
considered in patients using oral agents (e.g. for
assessing if additional Rx is required; to
confirm hypoglycaemia if symptomatic), but not
regularly and indefinitely
4
Singapore Ministry of
Health, 2006 [25]
systematic reviews
(2 ) randomized controlled trials
opinion ⁄ review papers
clinical practice guidelines
American Association
of Clinical
Endocrinologists,
2007 [26]
International Diabetes
Federation, 2007 [27]
3
2
1
1
3
4
1
3
Joslin Diabetes Center,
diabetes in the elderly,
2007 [28]
None
National Collaborating
Centre for Chronic
Conditions, 2008 [1]
4 systematic reviews
1 randomized controlled trials
5 non-randomized controlled trials
Canadian Diabetes
Association, 2008 [29]
4
2
8
1
Society of Endocrinology,
Metabolism and
Diabetes of South
Africa, 2009 [30]
6 clinical practice guidelines
1228
systematic reviews
(1 ) randomized controlled trials
non-randomized controlled trial
clinical practice guideline
systematic reviews
(2 ) randomized controlled trials
non-randomized controlled trial
clinical practice guidelines
systematic reviews
(1 ) randomized controlled trials
non-randomized controlled trials
clinical practice guideline
2
4
4
3.7
3
4
2.3
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
Review article
DIABETICMedicine
Table 1 (Continued)
Guideline, year and
reference
Publications cited
Conclusion of clinical practice guideline
Grading*
National Health and
Medical Research
Council, 2009 [31]
5 systematic reviews
2 (2 ) randomized controlled trials
6 non-randomized controlled trials
4
International Diabetes
Federation self-monitoring
of blood glucose
guideline, 2009 [14]
(4 systematic reviews were cited
but results were not referred
nor discussed)
6 randomized controlled trials
5 non-randomized controlled trials
Scottish Intercollegiate
Guidelines Network,
2010 [11]
6 systematic reviews
3 (3 ) randomized controlled trials
1 non-randomized controlled trials
British Columbia Ministry
of Health Services,
2010 [32]
1 systematic review
Joslin Diabetes Center,
diabetes in adults, 2010
[33]
Institute for Clinical
System Improvement,
2010 [13]
None
Veterans Affairs ⁄
Department of Defense,
2010 [12]
7 systematic reviews
2 (2 ) randomized controlled trials
NHS Diabetes, 2010 [34]
2 systematic reviews
American Diabetes
Association, 2011 [35]
1 systematic review
2 randomized controlled trials
Self-monitoring of blood glucose should be
considered in all people with Type 2 diabetes,
but the decision to perform self-monitoring, and
the frequency and timing of testing, should be
individualized
Self-monitoring of blood glucose should be
considered at the time of diagnosis and also be
considered as part of ongoing diabetes selfmanagement education to enhance the
understanding of diabetes as part of individuals’
education and to facilitate timely treatment
initiation and titration optimization
Routine self-monitoring of blood glucose in
people with Type 2 diabetes who are using oral
glucose-lowering drugs (with the exception of
sulphonylureas) is not recommended. Selfmonitoring may be considered in the following
groups of patients: those at increased risk of
hypoglycaemia; those experiencing acute illness;
those undergoing significant changes in
pharmacotherapy or fasting, for example, during
Ramadan; those with unstable or poor glycaemic
control
Encourage patients to accept responsibility for the
care of their diabetes and develop a mutually
acceptable management plan, including an
identified primary care provider and
individualized self-monitoring of blood glucose
Self-monitoring of blood glucose is an important
component of the treatment programme for all
people with diabetes
Major clinical trials assessing the impact of
glycaemic control on diabetes complications
have included self-monitoring of blood glucose
as part of multifactorial interventions, suggesting
that self-monitoring is a component of effective
therapy. The role of self-monitoring in stable
diet-treated patients with Type 2 diabetes is not
known
Consider self-monitoring of blood glucose in
patients who do not use insulin undergoing
initiation or change of therapy, illness or
hypoglycaemia unawareness, and the selfmonitoring data are used to adjust treatment
regimens
Self-monitoring of blood glucose should only be
provided routinely to people with Type 2
diabetes not treated with insulin or
sulphonylureas where there is an agreed purpose
or goal to testing
For patients using less frequent insulin injections,
non-insulin therapies or medical nutrition
therapy and physical activity alone, selfmonitoring of blood glucose may be useful as a
guide to the success of therapy
2 clinical practice guidelines
Mean value of grading
4
2
4
4
3.5
2.7
2.3
3.5
3.4
*See Methods.
Some (number in brackets) of the cited randomized controlled trials were included in systematic reviews that were also cited.
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
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Are self-monitoring of blood glucose recommendations evidence based? • K. M. Aakre et al.
Table 2 Mean value of guideline grading as stratified according to guideline characteristics; the mean grading of all guidelines was 3.4
Characteristic
Guideline and reference
Mean grading
Description of the clinical practice
guideline development process
International Diabetes Federation [2]
National Academy of Clinical Biochemistry [24]
American Association of Clinical Endocrinologists [26]
International Diabetes Federation [27]
National Collaborating Centre for Chronic Conditions [1]
Canadian Diabetes Association [29]
National Health and Medical Research Council [31]
International Diabetes Federation [14]
Scottish Intercollegiate Guidelines Network [11]
Institute for Clinical System Improvement [13]
Veterans Affairs ⁄ Department of Defense [12]
NHS Diabetes [34]
International Diabetes Federation [2]
International Diabetes Federation [27]
National Collaborating Centre for Chronic Conditions [1]
National Health and Medical Research Council [31]
Scottish Intercollegiate Guidelines Network [11]
International Diabetes Federation [2]
National Academy of Clinical Biochemistry [24]
American Association of Clinical Endocrinologists [26]
International Diabetes Federation [27]
National Collaborating Centre for Chronic Conditions [1]
Canadian Diabetes Association [29]
National Health and Medical Research Council [31]
International Diabetes Federation [14]
Scottish Intercollegiate Guidelines Network [11]
British Columbia Ministry of Health Services [32]
Veterans Affairs ⁄ Department of Defense [12]
NHS Diabetes [34]
American Diabetes Association [35]
National Academy of Clinical Biochemistry [24]
National Collaborating Centre for Chronic Conditions [1]
National Health and Medical Research Council [31]
International Diabetes Federation [14]
Scottish Intercollegiate Guidelines Network [11]
British Columbia Ministry of Health Services [32]
Veterans Affairs ⁄ Department of Defense [12]
NHS Diabetes [34]
American Diabetes Association [35]
International Diabetes Federation [2]
National Collaborating Centre for Chronic Conditions [1]
National Health and Medical Research Council [31]
International Diabetes Federation [14]
Scottish Intercollegiate Guidelines Network [11]
NHS Diabetes [34]
Singapore Ministry of Health [25]
American Association of Clinical Endocrinologists [26]
International Diabetes Federation [27]
Canadian Diabetes Association [29]
Institute for Clinical System Improvement [13]
American Diabetes Association [35]
National Academy of Clinical Biochemistry [24]
National Health and Medical Research Council [31]
Scottish Intercollegiate Guidelines Network [11]
Joselin Diabetes Center (adult) [33]
Veterans Affairs ⁄ Department of Defense [12]
National Collaborating Centre for Chronic Conditions [1]
International Diabetes Federation [2]
Joslin Diabetes Center (elderly) [28]
3.3
Patients involved in clinical practice guideline
development
Citing systematic reviews of randomized
controlled trials addressing the effect of
self-monitoring of blood glucose on HbA1c
Cost issues discussed
Quality-of-life issues discussed
Recommendation based on consensus*
Recommendation based on evidence*
Base of evidence not stated
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3.4
3.3
3.1
3.2
3.8
2.9
3.4
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Diabetic Medicine ª 2012 Diabetes UK
Review article
DIABETICMedicine
Table 2 (Continued)
Characteristic
Governmental organization
Private or professional organization
Clinical practice guideline sponsored by
industry funding
Guideline and reference
Society of Endocrinology Metabolism and Diabetes of
South Africa [30]
International Diabetes Federation [14]
British Columbia Ministry of Health Services [32]
NHS Diabetes [34]
National Collaborating Centre for Chronic Conditions [1]
National Health and Medical Research Council [31]
Scottish Intercollegiate Guidelines Network [11]
Singapore Ministry of Health [25]
British Columbia Ministry of Health Services [32]
Veterans Affairs ⁄ Department of Defense [12]
NHS Diabetes [34]
International Diabetes Federation [2]
American Association of Clinical Endocrinologists [26]
International Diabetes Federation [27]
National Academy of Clinical Biochemistry [24]
Joslin Diabetes Center (elderly) [28]
Canadian Diabetes Association [29]
Society of Endocrinology Metabolism and Diabetes of
South Africa [30]
International Diabetes Federation [14]
Joslin Diabetes Center (adult) [33]
Institute for Clinical System Improvement [13]
American Diabetes Association [35]
International Diabetes Federation [2]
International Diabetes Federation [27]
International Diabetes Federation [14]
Canadian Diabetes Association [29]
Mean grading
3.1
3.6
4.0
*As stated by the authors of the clinical practice guideline.
recommendations given and the grading carried out by our team
according to the scale described in Methods. Grading did not
differ by more than one point between each of the reviewers for
any guideline. The mean value of scores was 3.4 out of a maximum of 4.0 (most strongly recommending self-monitoring).
Table 2 shows the mean value of grading for the different
clinical practice guidelines as stratified according to guideline
characteristics. Industry funding and consensus-based recommendations seemed to increase grades, whilst governmental
funding, a discussion of costs or quality of life issues and basing
the recommendation on high-level evidence (as denoted by the
guideline authors) seemed to decrease them. A few guidelines
(mean grading 2.9) [11–14] gave some information about the
use of considered judgement but none provided detailed
information on this topic.
Table 3 shows the author’s conclusions and the grading of
the discussions and conclusions of the systematic review as
carried out by our team (described in Methods). Grading did
not differ by more than one point between each of the
reviewers for any systematic review. The average score was 2.2
out of 4.0. The reviews that cited non-randomized primary
studies had a similar average grade (2.1). The two articles
denoting funding from industry [15,16] were graded 3.0 and
3.5, respectively. It should be noted that Coster et al. published
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
two reviews based on the same eight randomized trials [17,18]
in 2000, yet the conclusions of these articles were graded
differently by our team (1.7 and 1.2, respectively). Also, the
two reviews Welschen et al. published in 2005 [19,20] were
graded differently: one article (based on six randomized and
seven non-randomized trials) was graded 3.8, whilst the other
(based only on the six randomized trials) was graded 2.2.
Table 4 shows the systematic reviews that were cited by the
guidelines (average mean grading 2.5) and also which systematic reviews that, even if they were available, were not cited
[average mean grading 2.1 (P-value for difference: 0.065)].
Twenty-one randomized trials were cited in the 15 systematic
reviews (see also Supporting Information, Table S1). All but
one review [21] had performed some kind of quality rating of
the included trials, and overall they concluded that the quality
of the included articles was low. Inclusion of randomized trials
that evaluated an educational intervention from which the
effect of self-monitoring of blood glucose could not be clearly
isolated was common: 10 of 21 papers (see also Supporting
Information, Table S1) and more common in papers that had a
conclusion in favour of self-monitoring (8 ⁄ 10). It was highly
variable which randomized trials were included or excluded
from the systematic reviews, even for the reviews published in
the same year (see also Supporting Information, Table S2).
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Are self-monitoring of blood glucose recommendations evidence based? • K. M. Aakre et al.
Table 3 Conclusions of systematic reviews evaluating the use of self-monitoring of blood glucose in patients with Type 2 diabetes mellitus who are not
using insulin
Systematic review
Studies included
Conclusion of systematic review
Grading*
Faas et al., 1997 [36]
6 randomized controlled
trials
5 non-randomized controlled
trials
1.8
Coster et al., 2000 [17]
8 randomized controlled
trials
Coster et al., 2000 [18]
8 randomized controlled
trials
Holmes and Griffiths,
2002 [21]
2 systematic reviews
1 randomized controlled trial
Welschen et al., 2005 [19]
6 randomized controlled
trials
Welschen et al., 2005 [20]
6 randomized controlled
trials
7 non-randomized controlled
trials
Sarol et al., 2005 [15]
8 randomized controlled
trials
Jansen, 2006 [16]
13 randomized controlled
trials
McGeogh et al., 2007 [37]
3 randomized controlled
trials
13 non-randomized
controlled trials
McAndrew et al.,
2007 [38]
11 randomized controlled
trials
18 non-randomized
controlled trials
Self-monitoring of blood glucose may be used in patients
who do not use insulin with poor glycaemic control,
although its effect has not yet been proven. The efficacy of
self-monitoring should be tested in a rigorous high-quality
randomized controlled trial
Blood glucose self-monitoring is well established in clinical
practice, but the optimal use of the technique has not been
established. Present evidence suggests that it may not be
essential for all patients. Randomized studies should be
carried out to provide decisive evidence on the clinical and
cost-effectiveness of self-monitoring in Type 2 diabetes
mellitus
The results do not provide evidence for clinical effectiveness
of an item of care with appreciable costs. Further work is
needed to evaluate self-monitoring so that resources for
diabetes care can be used more efficiently
The efficacy of blood and urine glucose monitoring testing,
for people with Type 2 diabetes, in improving glycaemic
control as measured by HbA1c levels is still questionable.
A randomized controlled trial is needed
The methodological quality of studies was low, and no
meta-analysis was performed. Self-monitoring of blood
glucose might be effective in improving glycaemic control
in patients with Type 2 diabetes who are not using insulin.
A large randomised controlled trial is required
The overall effect of self-monitoring of blood glucose was a
statistically significant decrease of 0.39% in HbA1c
compared with the control groups. This is considered
clinically relevant. This conclusion should be interpreted
with caution because of the methodological quality of the
included trials. A large randomized trial is needed
This study demonstrates that, in the short term, and when
integrated with educational advice, self-monitoring of
blood glucose as an adjunct to standard therapy may
contribute to improving glycaemic control among patients
with Type 2 diabetes who do not use insulin. We
emphasize that self-monitoring does not improve
glycaemic control in isolation
In conclusion, the randomized clinical trials performed to
date provided positive results on the effectiveness of
self-monitoring of blood glucose in reducing HbA1c in
Type 2 diabetes. Regular medical feedback of the results is
important. A definite judgement is difficult to make and
additional studies are recommended
Self-monitoring of blood glucose may not be helpful, or
economically justified, in all cases, but it seems likely that
individuals would benefit if: their baseline HbA1c level is
above 64 mmol ⁄ mol (8%); they are properly educated in
the use of self-monitoring and how to take appropriate
action based on the results; there are special
circumstances, such as new diagnosis, initiation or change
in medication, illness, gestational diabetes, lack of
awareness of hypoglycaemia
Self-monitoring may be effective in controlling blood
glucose for patients with Type 2 diabetes. There is a need
for studies that implement all the components of the
process for self-regulation of self-monitoring to assess
whether patient use of self-monitoring will improve HbA1c
levels
1232
1.7
1.2
1.5
2.2
3.8
3
3.5
2.8
2.5
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
Review article
DIABETICMedicine
Table 3 (Continued)
Systematic review
Studies included
Conclusion of systematic review
Grading*
Balk et al., 2007 [39]
5 randomized controlled
trials
6 non-randomized controlled
trials
1.3
Towfigh et al., 2008 [40]
9 randomized controlled
trials
Poolsup et al., 2008 [41]
9 randomized controlled
trials
Canadian Agency for
Drugs and Technologies
in Health, 2009 [42]
9 randomized controlled
trials
16 non-randomized
controlled trials
Clar et al., 2010 [43]
23 randomized controlled
trials
36 non-randomized
controlled trials
The studies may suggest a small, although possible
clinically non-significant, reduction in HbA1c with
self-monitoring of blood glucose, although overall the
studies are inconclusive. The effect on hypoglycaemia may
not be determined
Self-monitoring of blood glucose produces a statistically
significant but clinically modest effect in controlling blood
glucose levels in patients with diabetes not taking insulin.
It is of questionable value in helping meet target values of
glucose control
The available evidence suggests the usefulness of
self-monitoring of blood glucose in improving glycaemic
control in non-insulin-treated Type 2 diabetes, as
demonstrated by the reduction of HbA1c levels. In
particular, self-monitoring proved to be useful in the
subgroup of patients whose baseline HbA1c was > or =
64 mmol ⁄ mol (8%). Self-monitoring results have to be
incorporated into diabetes management regimes and
should lead to modifications in treatment
Pooling of randomized controlled trials demonstrated that
self-monitoring of blood glucose is associated with a
statistically significant, albeit clinically modest,
improvement in glycaemic control. No overall reduction
was seen in hypoglycaemia, except a single trial
demonstrated that self-monitoring may be beneficial in
reducing symptomatic hypoglycaemia in patients using
sulphonylureas. There was little or no evidence to suggest
that self-monitoring confers benefits regarding other
outcomes, such as quality of life, long-term complications
of diabetes or mortality. Future randomized controlled
trials may help identify specific subgroups of patients with
Type 2 diabetes who do not use insulin who are most
likely to benefit from self-monitoring
The evidence suggested that self-monitoring of blood
glucose is of limited clinical effectiveness in improving
glycaemic control in people with Type 2 diabetes on oral
agents, or diet alone, and is therefore unlikely to be
cost-effective
Mean value of grading
1.5
3.2
1.8
1
2.2
*See Methods.
Discussion
The main finding in this study was that, for persons with
diabetes who do not use insulin, clinical practice guideline
recommendations were more in favour of self-monitoring of
blood glucose than the systematic reviews evaluating the effect
of this intervention. It was not clear how considered judgement
was used upon development of recommendations. Funding by
industry seemingly led to a more positive attitude towards use
of self-monitoring.
Articles related to quality of life and cost issues were not
included in the overview of cited scientific evidence that is
presented in this review. Such studies were relatively scarce.
The main body of evidence to support recommendations on
self-monitoring of blood glucose was comprised of studies on
ª 2012 The Authors.
Diabetic Medicine ª 2012 Diabetes UK
the effect of self-monitoring on HbA1c. The guidelines that
cited articles related to cost or quality of life issues had a lower
mean grading (i.e. closer to the mean grading of appraised
systematic reviews) and it is therefore not likely that presenting
the literature cited related to quality of life or costs would have
changed the main conclusions in this review. Upon grading the
guidelines and systematic reviews, we used a system similar to
the scaling usually applied for grading guideline recommendations [22]. Even if this grading system is not validated for all
purposes (e.g. systematic reviews), only the use of a similar
scale makes comparison between guidelines and systematic
reviews possible. The non-randomized publications cited by
guidelines are not described in this study. This could be considered a limitation, but it is generally not advised that
recommendations are based on such publications if randomized
1233
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Are self-monitoring of blood glucose recommendations evidence based? • K. M. Aakre et al.
Table 4 The table shows the mean grading of the systematic reviews that were cited and not cited by the guidelines (only systematic reviews that were
published the year within the release of the guideline or earlier were included for comparison).
Cited systematic reviews
Non-cited systematic reviews
Guideline
Grading
Reference
Grading
Reference
International Diabetes Federation, 2005 [2]
National Academy of Clinical Biochemistry, 2006 [24]
American Association of Clinical Endocrinologists, 2007 [26]
International Diabetes Federation, 2007 [27]
National Collaborating Centre for Chronic Conditions, 2008 [1]
Canadian Diabetes Association, 2008 [29]
National Health and Medical Research Council, 2009 [31]
Scottish Intercollegiate Guidelines Network, 2010 [13]
British Columbia Ministry of Health Services, 2010 [32]
Veterans Affairs ⁄ Department of Defense, 2010 [12]
NHS Diabetes, 2010 [34]
American Diabetes Association, 2011 [35]
Total
2.7
1.5
3.4
2.6
3.1
2.3
2.8
2.5
1.8
2.5
1.1
3.8
2.5
[15,18,20]
[18,36]
[15,16,20]
[15,16,18]
[15,16,19,20]
[18–20,36]
[16,20,36–38,40]
[15–17,19,38,42]
[42]
[15,16,19,37,39–41]
[18,43]
[20]
1.8
2.4
1.7
2.2
1.8
2.3
1.8
2.1
2.2
1.9
2.4
2.1
2.1
[17,19,21,36]
[15,17,19–21]
[17–19,21,36]
[17–19,21,36]
[17,18,21,36–39]
[15–17,21,37–39]
[15,17–19,21,39]
[18,20,21,36,37,39–41]
[15–21,36–41,43]
[17,18,20,21,36,38,42,43]
[15–17,19–21,36–42]
[15–19,21,36–43]
Only guidelines (12 of 18) that cited one or more systematic reviews are included. The International Diabetes Federation self-monitoring of
blood glucose guideline [14] mentions that systematic reviews exist and cites four [37,38,40,41], but does not discuss the results or
conclusions and is therefore not included in this comparison.
trials are available, because of their larger heterogeneity and
their lower ranking in the evidence hierarchy [22]. Randomized
trials are intended to eliminate bias arising from treatment
assignment that cannot be assessed with other study designs,
and this issue is of particular importance with the evaluation of
self-monitoring of blood glucose.
An earlier study showed that the number of recommendations
in clinical practice guidelines based on low-quality evidence is
high and increasing [23]. The current data indicate that recommendations might be influenced by different biases. First,
financial bias may be present as industry funding was associated
with a more positive approach towards use of self-monitoring.
This was seen both for guidelines and systematic reviews when
the publication was sponsored by industry and also for guidelines that were published by an organization that was depending
on industry funding. Secondly, only 13 of 18 clinical practice
guidelines cited systematic reviews or randomized trials, so in
1 ⁄ 3 of the guidelines the available scientific evidence is not
presented; this indicates citation bias. This assumption is also
strengthened by the finding that systematic reviews interpreting
the data more in favour of self-monitoring were cited more
frequently compared with simultaneously available but less
supportive reviews. An obvious shortcoming of systematic
reviews was that many included randomized trials evaluating
educational programmes from which the effect of self-monitoring could not be isolated. Finally, many guidelines did not
discuss quality of life or costs and none was completely clear
and explicit about how considered judgment had been used in
development of the recommendation. Based on these findings, it
may be concluded that the principles of evidence-based medicine were not adhered to in the evaluated clinical practice
guidelines.
1234
Even although some weaknesses in randomized trials, systematic reviews and clinical practice guidelines are highlighted
in our study, important questions for the users of guidelines
remain to be answered: how to ensure that recommendations
are based on the total volume of available evidence and that
authors are explicit about how considered judgment influenced
the advice given.
Competing interests
Nothing to declare.
Acknowledgement
The study was funded by the European Federation of Clinical
Chemistry. The sponsor had no influence of the study design
and the collection, analysis and interpretation of data and the
writing of the article and the decision to submit it for publication. The data have been presented as an abstract at the
IFCC-WorldLab Berlin 2011; 15–19 May 2011.
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Supporting Information
Additional Supporting Information may be found in the online
version of this article:
Table S1. An overview of primary studies (randomized controlled trials) cited by the systematic reviews.
Table S2. . Overview of available randomized controlled trials
included, excluded or not mentioned by different systematic
reviews.
Please note: Wiley-Blackwell are not responsible for the content
of functionality of any supporting materials supplied by the
authors. Any queries (other than for missing material) should
be directed to the corresponding author for the article.
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Diabetic Medicine ª 2012 Diabetes UK