Background

The prevalence of type 2 diabetes (T2DM) has been rising in the UK, and around 4% of the population now have the condition.

Good control of blood glucose level is important in preventing or delaying the complications of T2DM, such as heart disease, peripheral vascular disease, visual loss and renal failure.

However, many people with T2DM do not have good control of their blood glucose.

The usual method for monitoring glycaemic control is by measuring glycated haemoglobin, or HbA_1c, which gives an average of the blood glucose over 3 months. If it is high then control needs to be improved. The National Institute for Health and Clinical Excellence (NICE) recommends that most people with T2DM should aim to keep their HbA_1c level at 6.5% or under, though targets should be tailored to the individual.

However, HbA_1c level does not tell patients what their blood glucose is doing on a day-to-day basis. Self-monitoring by testing for urinary glucose is one way of checking when blood glucose is high, but is only a rough guide. A more accurate measure can be obtained by blood testing, which is done by pricking the skin to get a drop of blood, putting that blood on a testing strip, and reading the result with a small meter. This can be done at different times of day, before or after meals, or before or after physical activity.

Meters are cheap (about £14), and the NHS requires manufacturers to provide them free of charge if needed, so the main cost is the test strips, at about £14 for a pack of 50.

Main question

Is self-monitoring of blood glucose worthwhile in people with T2DM who are not treated with insulin or who are on only basal insulin in combination with oral agents, in terms of glycaemic control, hypoglycaemia, quality of life (QoL) and other relevant outcomes, and cost per quality-adjusted life-year (QALY)?

Methods

Review of systematic reviews published since 1996, and a systematic review and meta-analyses of randomised controlled trials (RCTs) identified from the reviews, and from searches for more recent trials. Review of qualitative and economic studies.

Results

Conclusions

The current evidence suggests that SMBG is of limited clinical effectiveness in improving glycaemic control in people with T2DM on oral agents, or diet alone, and is therefore unlikely to be cost-effective. There were insufficient data for those on a single basal insulin to reach any conclusion. No data are available on the possible benefits of SMBG in selected patient subgroups. SMBG can be expected to lead to improved glycaemic control only in the context of appropriate education – both for patients and HCPs – on how to respond to the readings, in terms of lifestyle and treatment adjustment. It may be more effective if patients are able to self-adjust drug treatment.

In the authors’ opinion, at a time when funds are scarce, the case for investment in blood glucose monitoring in T2DM, in patients who are not treated with insulin, is not proven. Further research is required on the type of education and feedback that are most helpful, characteristics of patients benefiting most from SMBG, optimal timing and frequency of SMBG, and the circumstances under which SMBG causes anxiety and/or depression.

Publication

• Clar C, Barnard K, Cummins E, Royle P, Waugh N. Self-monitoring of blood glucose in type 2 diabetes: systematic review. Health Technol Assess 2010;14(12). [PubMed: 20226138]

NIHR Health Technology Assessment programme

The Health Technology Assessment (HTA) programme, part of the National Institute for Health Research (NIHR), was set up in 1993. It produces high-quality research information on the effectiveness, costs and broader impact of health technologies for those who use, manage and provide care in the NHS. 'Health technologies' are broadly defined as all interventions used to promote health, prevent and treat disease, and improve rehabilitation and long-term care.

The research findings from the HTA programme directly influence decision-making bodies such as the National Institute for Health and Clinical Excellence (NICE) and the National Screening Committee (NSC). HTA findings also help to improve the quality of clinical practice in the NHS indirectly in that they form a key component of the 'National Knowledge Service'.

The HTA programme is needs led in that it fills gaps in the evidence needed by the NHS. There are three routes to the start of projects.

First is the commissioned route. Suggestions for research are actively sought from people working in the NHS, from the public and consumer groups and from professional bodies such as royal colleges and NHS trusts. These suggestions are carefully prioritised by panels of independent experts (including NHS service users). The HTA programme then commissions the research by competitive tender.

Second, the HTA programme provides grants for clinical trials for researchers who identify research questions. These are assessed for importance to patients and the NHS, and scientific rigour.

Third, through its Technology Assessment Report (TAR) call-off contract, the HTA programme commissions bespoke reports, principally for NICE, but also for other policy-makers. TARs bring together evidence on the value of specific technologies.

Some HTA research projects, including TARs, may take only months, others need several years. They can cost from as little as £40,000 to over £1 million, and may involve synthesising existing evidence, undertaking a trial, or other research collecting new data to answer a research problem.

The final reports from HTA projects are peer reviewed by a number of independent expert referees before publication in the widely read journal series Health Technology Assessment.

Criteria for inclusion in the HTA journal series

Reports are published in the HTA journal series if (1) they have resulted from work for the HTA programme, and (2) they are of a sufficiently high scientific quality as assessed by the referees and editors.

Reviews in Health Technology Assessment are termed 'systematic' when the account of the search, appraisal and synthesis methods (to minimise biases and random errors) would, in theory, permit the replication of the review by others.

The research reported in this issue of the journal was commissioned by the HTA programme on behalf of the Department of Health as project number 09/19/01. The contractual start date was in February 2009. The draft report began editorial review in August 2009 and was accepted for publication in December 2009. As the funder, by devising a commissioning brief, the HTA programme specified the research question and study design. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the referees for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.

The views expressed in this publication are those of the authors and not necessarily those of the HTA programme or the Department of Health.

Editor-in-Chief: Professor Tom Walley CBE

Series Editors: Dr Martin Ashton-Key, Dr Aileen Clarke, Professor Chris Hyde, Dr Tom Marshall, Dr John Powell, Dr Rob Riemsma and Professor Ken Stein