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Wednesday, April 30, 2008

Is Testing Worthwhile?

I have friends in the UK who are finding it increasingly difficult to get adequate test strip supplies prescribed from their NHS surgeries to use self-monitoring of their blood glucose (SMBG) in the way that enabled them to gain control of their type 2 diabetes. I am fortunate to live in Australia where the NDSS subsidises test strips. However, I am becoming concerned at several poor "studies" conducted in Australia, Canada and the UK implying that SMBG is a waste of money and time and may also cause depression.

I suspect that it is no coincidence that all of those countries subsidise test strip supplies for diagnosed diabetics. I fear a concerted push by the "bean-counters" in our various health systems to cut costs in this area; a very short-sighted view of diabetes treament in my opinion. I am convinced that systematic use of SMBG to improve and maintain dietary control of type 2, complementary to any medication or insulin treatments, will lead to much greater savings in the long term in both the cost of treating complications and the overall social and economic costs to the community.

The most recent flawed study was published in the British Medical Journal: Efficacy of self monitoring of blood glucose in patients with newly diagnosed type 2 diabetes (ESMON study): randomised controlled trial The crux of the problem in this study lies in the following section.

First, I'll give the unabridged version, then highlight some points. You can save time by scrolling down to "This is the absolutely critical part".

From the study: "After an initial assessment visit, eligible patients were randomised into intervention (self monitoring of blood glucose) or control (no monitoring) groups with a randomly generated allocation code in consecutively numbered sealed envelopes. The study diabetes nurse at each hospital site performed the treatment allocation.

Patients in the self monitoring group were all provided with a single glucose monitor (Lifescan OneTouch Ultra; Johnson and Johnson, Milpitas, CA) and instructed in its use. They were asked to monitor four fasting and four postprandial capillary blood glucose measurements each week. They were advised on appropriate responses to high or low readings. Such advice included the need for dietary review or the suggestion of exercise (such as walking) in response to high readings.

At each clinic visit, concordance with the self monitoring regimen was verified by downloading meter readings.

Patients in the no monitoring group (control) were asked not to acquire a meter or perform monitoring for the duration of the study. Patients in both groups underwent an identical structured education programme involving diabetes nurse practitioners, dieticians, podiatrists, and medical staff. All patients were reviewed by the doctor, diabetes nurse practitioner, and dietician at three monthly intervals for one year. At each visit all aspects of diabetes care were reviewed including indices of glycaemic control (HbA1c for both groups and self monitoring results for the self monitoring group).

Patients in the self monitoring group received ongoing advice and support in the appropriate interpretation of and response to their capillary glucose results. We used an identical treatment algorithm for dietary and pharmacological management of glycaemia for both groups based on HbA1c targets (figure 1). Blood concentrations of HbA1c, lipids, and electrolytes were measured at or before each clinic and results were discussed with patients in the context of the treatment targets. Measurement of HbA1c was performed in the local hospital laboratory with a diabetes control and complications trial (DCCT) aligned HbA1c assay.2 All laboratories participated in HbA1c external quality assurance, which was satisfactory for the duration of the study. All other laboratory tests were also performed in the local hospital laboratory, where staff were blinded to treatment allocation."

This is the absolutely critical part:

"They were asked to monitor four fasting and four postprandial capillary blood glucose measurements each week. They were advised on appropriate responses to high or low readings. Such advice included the need for dietary review or the suggestion of exercise (such as walking) in responseto high readings."

What were the "appropriate" responses they used? What was that advice?

Some idea of what may have been advised appears here: "Patients in both groups underwent an identical structured education programme involving diabetes nurse practitioners, dieticians, podiatrists, and medical staff."

And what do we know of the education dietary programme provided by the NHS or Diabetes UK(see P788 table 2)? Basically it is low-fat, high carb and add more metformin or insulin to counter the carbs. On the use of meds, take a look at Table 5 noting the increase in medications across the board and the higher use of multiple medications in the SMBG group.

When these meter users tested at their random four post-prandials (or, at least, the 63 of 96 who actually tested 80% of the required four FBG and four PP weekly; meaning that 50% actually tested that much, almost certainly at two hours and well after their post-prandial spike), what did they do about it if it was high? Did they reduce carbs? Possible, but most unlikely if they complied with their advice. More likely they went for a walk or the doctor upped their metformin or added a med (see Figure 1 and Figure 5). And they probably missed most of their spikes anyway, often seeing only the reactive post-spike numbers at two hours.

So they did what they were told and their numbers didn't improve. No wonder they got depressed. I would have too. What was that old definition for insanity? "To continue to do the same thing and expect a different result."

In my opinion the control group weren't as depressed because they put themselves in the hands of their doctors - no personal responsibility for their plight. But the SMBG group felt they must share the blame for their poor response; especially those who were in the 50% who didn't do all the weekly tests.

The problem was not the SMBG but the ignorance of those conducting the research on how to best train the SMBG group on how to use the test results to improve the diet to improve results. This research follows the earlier and similar BMJ report from Farmer et al, which I note is listed as the 13th reference: Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: open parallel group randomised trial You will see my response to that in BMJ at the foot of that page. It is equally relevant to this load of nonsense. If you go to the ready response index you will find several other patient's and doctor's similar responses.

The only funding acknowledgement for this latest nonsense was "Funding: Northern Ireland research and development office. MC was employed as a research associate as part of the funding allocation. The blood glucose meters were supplied free of charge by Johnson and Johnson, Milpitas, CA." I am cynical enough to wonder how much of the funding effectively came from the bean-counters of the NHS.

Cheers, Alan

Everything in Moderation, Except Laughter