Type 2 Diabetes and Medication Adherence: Where is the Disconnect?

September 10, 2013

Incretin drugs, which offer ease of use, very little hypoglycemia, and no weight gain (or even weight loss) seem to be an ideal therapy. But 80% to 90% of patients don’t stay on them. Why not?

In a poster presented at the 2013 ADA Scientific Sessions it was revealed that 89% of GLP-1RA and 82% of DPP-4 inhibitor users stopped their medications during the first year of treatment.  Why such a significant lack of persistence? 

These results are somewhat alarming. The incretin drugs, which offer ease of use, very little hypoglycemia, and no weight gain (or even weight loss) seem to be an ideal therapy.  But 80% to 90% of patients don’t stay on them. Why not?

I think cost has to be a major contributor to discontinuation. These drugs, along with their significant benefits, are expensive. Many patients just can’t bear the financial burden. While manufacturer’s savings cards help with the “sticker shock” for many products, our Medicare patients are largely left out of the cost savings. But if cost of therapy were the only reason people stop taking these medications, you would not expect such high discontinuation rates. It’s improbable that up to 90% of users are over age 65 and ineligible for the savings cards. Something else must be going on.

Adverse events? Other?
Side effects are an unlikely cause for discontinuation, especially with the DPP-4 inhibitors; these agents in particular are nearly free of side effects. Even the GLP-1 RA’s are usually quite well tolerated after several months. The registration trials with these drugs showed discontinuation rates for adverse events nowhere near 90%--so something else, again, must be going on.

We could postulate injection fatigue as a reason for stopping the GLP-1 RA’s. In my experience, however, there is more resistance to the initiation of injections than to their continued use since the process becomes second nature.

I believe, personally, that there is a lack of understanding and engagement in their diabetes care on the part of our patients. The American Diabetes Association addresses this in their new consensus statement on treatment of type 2 diabetes. They call for a patient-centric approach in crafting a diabetes treatment strategy and implementing therapies. This strategy places the responsibility for treating diabetes where it belongs – in the shared arena of the doctor patient relationship. Such a strategy gives all the players some skin in the game, fully engaging everyone.

Partnership between patient and doctor in the decision making process stresses the fact that it is the patient’s disease. The patient needs to understand what therapies do, what side effects to expect, what benefits to anticipate, what costs to plan for, etc. Motivational interviewing at follow-up visits is an excellent tool to help assess the patient’s desires, fears, frustrations, and readiness for change. I will disucss the technique in my next blog.

While this patient-centric approach and motivational interviewing may change how the usual office visit goes, it does not have to complicate or lengthen the process. Transferring ownership of therapeutic choices and plans to the patient ensures more likely buy-in and long-term persistence in using antidiabetic medications. 

Of course, this process has to start with well-educated providers. Clinicians must know about each of the dozen or so classes of antidiabetic therapies and be able to transfer that knowledge to their patients. The most effective strategy for treating diabetes will come from a combination of the clinician’s expertise and the patient’s desire for improvement. Once the patient has been given and has accepted ownership of the entire process they are well on the way to persisting in their plan for therapy.

 Koro CE, Chhabra P, Stender M, Spain CV, Allen JK, Krzywy HJ. Treatment utliziation patterns of GLP-1 agonists and DPP-4 inhibitors in type 2 diabetics in a US commercially insured population: 2005-2011. 73 rd Scientific Sessions, American Diabetes Association; June 21-25, 2013; Chicago, Ill. Poster #1589P