The DiGEM trial protocol – a randomised controlled trial to determine the effect on glycaemic control of different strategies of blood glucose self-monitoring in people with type 2 diabetes [ISRCTN47464659]

Abstract

BackgroundWe do not yet know how to use blood glucose self-monitoring (BGSM) most effectively in the self-management of type 2 diabetes treated with oral medication. Training in monitoring may be most effective in improving glycaemic control and well being when results are linked to behavioural change.Methods/designDiGEM is a three arm randomised parallel group trial set in UK general practices. A total of 450 patients with type 2 diabetes managed with lifestyle or oral glucose lowering medication are included. The trial compares effectiveness of three strategies for monitoring glycaemic control over 12 months (1) a control group with three monthly HbA1c measurements; interpreted with nurse-practitioner; (2) A self-testing of blood glucose group; interpreted with nurse- practitioner to inform adjustment of medication in addition to 1; (3) A self-monitoring of blood glucose group with personal use of results to interpret results in relation to lifestyle changes in addition to 1 and 2.The trial has an 80% power at a 5% level of significance to detect a difference in change in the primary outcome, HbA1c of 0.5% between groups, allowing for an attrition rate of 10%. Secondary outcome measures include health service costs, well-being, and the intervention effect in sub-groups defined by duration of diabetes, current management, health status at baseline and co-morbidity. A mediation analysis will explore the extent to which changes in beliefs about self-management of diabetes between experimental groups leads to changes in outcomes in accordance with the Common Sense Model of illness. The study is open and has recruited more than half the target sample. The trial is expected to report in 2007.DiscussionThe DiGEM intervention and trial design address weaknesses of previous research by use of a sample size with power to detect a clinically significant change in HbA1c, recruitment from a well-characterised primary care population, definition of feasible monitoring and behaviour change strategies based on psychological theory and evidence, and measures along the hypothesised causal path from cognitions to behaviours and disease and well being related outcomes. The trial will provide evidence to support, focus or discourage use of specific BGSM strategies.

Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: open parallel group randomised trial

“…The trial was managed from the coordinating centre at the Department of Primary Health Care, University of Oxford. 9 Our primary aim was to determine whether haemoglobin A 1c (HbA 1c ) levels at 12 months were significantly different between patients with non-insulin treated type 2 diabetes receiving one of three allocated interventions: standardised usual care with measurements of HbA 1c levels by health professionals every three months (control group); use of a blood glucose meter, with advice for participants to contact their doctor for interpretation of results (less intensive self monitoring); and use of a blood glucose meter with training in self interpretation and application of the results to diet, physical activity, and drug adherence (more intensive self monitoring).…”

Cost effectiveness of self monitoring of blood glucose in patients with non-insulin treated type 2 diabetes: economic evaluation of data from the DiGEM trial

“…The rationale for this comparator has been set out elsewhere. 26 It is possible, however, that in some settings patients are not receiving care to the standards of current practice guidelines. Provision of care in accordance with current recommendations should be a priority.…”

Is Self-Monitoring of Blood Glucose Appropriate for All Type 2 Diabetic Patients?

“…One such a trial may be the DiGEM (Diabetes Glycemic Education and Monitoring) study, the findings from which are due to be reported in 2007. DiGEM should establish whether SMBG is effective over a 12-month period when results are 1) interpreted by the patient and applied to lifestyle (selfmonitoring group), in addition to 2) nurse-practitioner interpretation to inform medication adjustment (self-testing group), compared with, and in addition to, 3) standardized usual care and 3-monthly A1C measurements (control group) (48). Non-insulin-treated type 2 diabetic patients aged Ն25 years are eligible.…”