I am an educator in a patient centered medical home. There are seven physicians and three nurse practitioners in our practice. I am often the one who teaches how and why to SMBG. I also frequently review the results with the patient and help them analyze, problem solve and titrate doses of medicines.
Recentlly I read a few articles in Diabetes Spectrum ( Summer 2012 issue) about Glycemic variability in the use of Point of Care Glucose Meters and Glycemic variability in evaluating diabetes control. This got me thinking about some of the current challenges I face in getting BG data from patients and having confidence in the accuracy of the data.
On getting the data to assess glcuose control and variability... I am surprised when patients do not know thier "targets". I have heard patients comment that they "used to monitor but the results were always the same, so I stopped". People often think of their DM as a stable unchanging disease. I see mostly Type 2 patients who sometimes only test once per day. One strategy that I use that I have found fairly successful is to define two major objectives for monitoring, after setting/redefining their BG targets This strategy is based on the principal that patients and care givers are partners in care and this approach encourages involvement in treatment. The first objective is self assessment of control over time, changes in food choices, medical conditions, exercise, etc. A common attitude is testing makes a person feel guilty and that providers will scold them about their results and the implied behaviors. I usually say something like, :Look, if your BG results continue to be out of your target despite your efforts ( or lack of), the monitoring will help you decide when you need to discuss your treatment with your provider. The results are simply data for you to assess your control.
The second objective, I explain, is to help your povider decide on the most efficacious treatment plan. This is the time for more frequent testing over a shorter period of time to give the providers useful data. I like using the 360 view developed by Roche. When that seems overwhelming to patients, I just use a log book that includes columns for per and post meals and bedtime readings. If the "intensive testing " is short term, most are willing to comply. Some are willing to do the continuous glucose monitoring for a week. Both of these approaches help us point out variability and can lead to some experimentation of some behaviors ( usually food choices) to reduce variability. A measure of glucose variability over a period of time can be a standard deviation ( intra or between day) which can be done with some of the BGM software. Other measurements mentioned the the article include MAGE ( mean amplitude of glucose excursions) and the MODD ( mean of daily differences). the latter two require continuous glucose monitoring as they require more data points to calculate.
Does this approach always get the data or the involvement? I don't always get the data or the involvement but some of that is life gets in the way of keeping logs or remembering to bring the log to the visit. But persistance does pay off.
However, the second problem. The article about glucose variability in Point of Care Glucose Meters brings me to the situation of advising patients on glucometers. I often get asked, " Is this an accurate meter, look at the variabiltiy in my results even at the same time?". This problem lurks in the background even when asking patients to test more often to assess variability. I used to rely on 3-4 meters that were generally accepted by the professional community as accurate. I used to get visits by representatives of the companies explaining the accuracy studies. Most insurances paid for whatever meter we reccommended. Now I am seeing insurance companies pay only for certain meters and supply companies only carrying certain meters. Is this because of accuracy or cost? It seems like there is an explosion of meters and I don't have data on all of them, (nor could I keep it all in my instant recall anyway). People are also buying stips online and are being solicited by "no finger pricks" and cheap strips. Am I the only one confused by this?
Anyway, I hear at AADE that standards for meters were changing, so I tried to do a little research to understand what the standards are and where they come from.
Before a manufacturer can market a BGM the FDA requires that 95% of individual results fall within +/- 20% at glucose concentrations >=75mg/dl and 95% of individual results fall within +/- 15% of the reference measurement at glcuose concentrations of <75mg/dl. Forthcoming standards ( January 2013???) tighten accuracy to +/-15% for the upper level. The organization that develops these requirements is the InternationOrganization for Standardization (ISO). Currently all OTC BGMs are automatically CLIA waived. If this automatic CLIA waiver was dropped, manufacturers would have to submit more robuse studies and meet stricter requirements. Normally this would require that 95% of reusults fall within +/-15% for values >=75mg/dl and +/-12% for values <75mg/dl. Additionally the other 5% of the values not "counted" would be reviewed to make sure there weren't too many distant outliers and a minimum of 360 sampes must be tested vs the 100 for the automatically or non-waived devices. Also, the FDA does not publish the accuracy data of the approved BGM. Now I know why I haven't been able to get my hands on a comparison chart!
So when I get asked, "Is this meter accurate?", my answer now is, "It has met minimum standards , but make sure you follow directions correctly to avoid user created errors." With type 1 patients, I usually still steer them to some of the more established brands. I also encourage people to bring their meters with them to their annual lab tests and take a POC test at the same time as the draw to compare results.
I would appreciate any updates on this issue of POC accuracy and the status of the CLIA waiver for OTC meters. Do others think Gucose variabilty is another important measurement to use for involving patients in their DM management? I'd like to hear how others are using this data.