Blood Glucose testing for non-insulin users
Towards the end of last year NICE (The National Institute for Health and Care Excellence) published new guidelines on the treatment of Type 2 (T2) diabetes. As part of these, they recommended further restrictions on Self-Testing of Blood Glucose (STBG) for T2 People With Diabetes (PWD), listing only a handful of exceptions (pregnancy, insulin use etc.). A similar approach is increasingly being seen in many publically funded healthcare systems around the world.
This advice is based on the very reasonable argument that the overall effect of self-monitoring is small, and there is therefore no cost effective benefit to STBG for PWD. I am supportive of a scientific and evidence based approach to medical treatment, but what prompted me to look into this further was that this argument stands in stark contrast to my personal experience, and to the experience of a great many T2 PWD who have good Blood Glucose (BG) control. For us, STBG forms a key part of our self-management strategy; it allows us to understand the effect that different foods and physical activities have on our BG, and also to better fathom the complex and unpredictable impact that the stresses and strains of day to day life have on our condition. Regular STBG equips us with the knowledge to change small behaviours in our everyday lives that can have a big impact on our BG control. Furthermore it gives us a feeling of empowerment and the (admittedly small) element of control it gives us over this difficult condition is a powerful source of psychological support, and a constant reminder about the need to positively engage in our own treatment.
Reflecting on this it seems that taking a closer look at the science behind the argument is worthwhile. In recent years there have been a significant number of different clinical trials that have considered the benefits of STBG, but a recent systematic review[1] of the trials is perhaps often quoted most by proponents of the cost/benefit argument in this context.
This systematic review combines the results of 12 clinical trial, covering over 3,250 participants, aiming to look at all the data fairly, and drawing conclusions from all studies on the topic and overcoming concerns that individually the studies are not large enough to be significant. Whilst this review process can give us confidence about the quality of the studies covered, and in theory increased certainty from the larger number of participants, it is clear from the start that the individual studies are very varied. Not only do they have diverse methods (not all studies provided instructions on how and when to test), but across the studies the frequency of testing varied between 4 times a months to 6 times a day. All studies looked at HbA1c as the outcome (a laboratory test that gives an overall picture of what average blood sugar levels have been over a period of weeks), but there was no consistent consideration of broader outcomes such as empowerment, patient distress, satisfaction with treatment and overall quality of life.
What is clearly missing in these studies is a common approach to structured education; how to successfully use regular testing to improve the patient’s knowledge of the condition. It is only through learning from the tests that we undertake that we can hope to improve our BG control, and far too many of these studies have failed to recognise this. Without the tools to identify patterns in the results, the data gathered is of little use to a patient, and we should not be surprised that average BG levels are not improved.
I think it can be concluded that it is not that there is no evidence to support STBG, but rather that incomplete questions are being asked and the right sort of evidence has not been gathered and interpreted. STBG not only has the ability to improve the lives and clinical outcomes of PWD, but when considered against the high costs of treating can complications arising from T2 Diabetes should be considered as a cost saving measure. Is there a case for Diabetes UK and those PWD who have found success in achieving good BG control through STBG to inform the next generation of research?
[1] Malanda UL, et al, Cochrane Database Syst Rev. 2012 Jan 18;1:CD005060. doi: 10.1002/14651858.CD005060.pub3
