Why some diabetics don't take their medication

University of Otago research into what helps and hinders people with type 2 diabetes correctly taking, and continuing to take, metformin, features in New Zealand Medical Journal.

Metformin is the first-line treatment for type 2 diabetes; a previous Otago study examined national pharmaceutical dispensing data and found that metformin adherence (taking it as prescribed) and persistence (continuing to take it) varied by patient characteristics such as age and ethnicity.

However, the researchers wanted to fill a gap in information about New Zealand patient perspectives on enablers of, and barriers to, optimal adherence and persistence.

They interviewed 10 Māori, 10 Pacific, and 10 non-Māori non-Pacific patients who had started metformin within the previous two years and identified several barriers to metformin adherence and persistence—these included delays in accepting the diagnosis of type 2 diabetes; the cost of visiting a doctor and prescription charges; complex and busy lives; and feelings of guilt and shame about having diabetes and/or poor control of blood sugars that prevented people from visiting their doctor.

Participants' comments highlighted the importance of developing and maintaining good patient/healthcare provider relationships and tailoring communication styles to the preferences of patients.

Some Māori and Pacific participants also emphasized the importance of having Māori and Pacific healthcare providers who shared their cultural identity and language.

Lead author Associate Professor Lianne Parkin, of the Department of Preventive and Social Medicine and the Pharmacoepidemiology Research Network, says it was important to do the study because some international research has found that although patients and healthcare providers share similar views about some of the barriers to adherence and persistence, there are also some differences.

"For example, healthcare providers may attribute patients' sub-optimal adherence and persistence to a lack of motivation and insufficient understanding of the physiological and biomedical aspects of type 2 diabetes, whereas broader personal, social, and practical challenges are often foremost for people living with type 2 diabetes. Such differences have obvious implications for developing effective interventions to enhance medication adherence and persistence."

Key points:

• Developing an understanding of type 2 diabetes, and the important role that medication plays in its management, was a dynamic process that occurred at differing speeds for different individuals. Delays in accepting the diagnosis of type 2 diabetes had a negative effect on initial adherence and persistence.
• Participants' comments highlighted the importance of developing and maintaining good patient/healthcare provider relationships and tailoring communication styles to the preferences of patients. Some Māori and Pacific participants also emphasized the importance of having Māori and Pacific healthcare providers who shared their cultural identity and language.
• The cost of visiting a doctor and prescription charges were issues for some participants.
• Some participants frequently missed a metformin dose, and this was most often unintentional and related to complex and busy lives with competing demands.
• There was a common lack of understanding that type 2 diabetes is a progressive disease and that a need to intensify treatment is not synonymous with personal failure on the part of people with the disease. Some participants appeared to carry a heavy burden of self-recrimination for having diabetes and/or sub-optimal control of blood sugars—feelings that sometimes prevented them from visiting their doctor.
• Participants talked about metformin helping to prevent long-term complications of diabetes such as eye damage, lower-limb amputation, and kidney failure requiring dialysis, but interestingly did not mention coronary heart disease or stroke. This suggests either a lack of awareness that cardiovascular disease is the leading cause of ill health and death among people with type 2 diabetes, or that losing sight, a limb, or kidney function was of greater importance.
• The most commonly discussed negative aspect of taking metformin was the gastrointestinal disturbances. For some participants, nausea, diarrhea, and other gastrointestinal symptoms were reasonably mild and short-lived, while in others they were severe and had a substantial impact on life and work. Participants with severe symptoms often reduced the dose of metformin (either on the advice of their doctor or of their own volition) or changed the time(s) they took metformin, while some stopped taking metformin altogether (either temporarily or longer term).
• Many participants mentioned the internet as a source of help for metformin-related issues, although only a few considered the trustworthiness of the sites they visited. In addition, not all participants had access to a computer or a smart phone, highlighting the need to provide patients with resources through a variety of channels as it cannot be assumed that online resources will suit everyone.
• Some Māori participants said they would have preferred to use traditional Māori medicines rather than metformin.