The OPTIMAAL study: Shared decision making between patients and GPs in the treatment of type 2 diabetes in primary care.

Over the past decades, the importance of self-management in the treatment of
type 2 diabetes (T2DM) has increased considerably. As a consequence, an
increasing amount of responsibility shifts towards the patients. Unfortunately,
although numerous patients are willing to take this responsibility, only few
receive it. An adaptation of attitude from the health care provider (HCP) is
essential to increase T2DM patients' responsibility. We believe that shared
decision making (SDM) covers a potential solution where both parties reach a
decision together. As only 20% of the T2DM patients reach all T2DM treatment
goals we hypothesise that SDM can improve this percentage by increasing patient
involvement in treatment decisions.
The SDM is especially important if there is more than one possible treatment
option, and these options are equally suitable in treating the condition. This
is the case in T2DM, because the ADDITION trail (METC prtocol number 01/292)
showed that neither treatment according to national guidelines, nor more
intensive treatment according to ADDITION guidelines has a proven superior
effect. This is the reason that we want to recruite the former ADDITION
patients, and offer them choice between two evidence based treatment options.
The studied intervention (shared decision making) will also be applicable for
all the other patients in the general practice. This means that not only the
former ADDITIONpatients will be eligible for participation, but other T2DM
patients as well, with comparable patient characteristics.

Objective: this study aims to investigate whether SDM may increase the amount
of T2DM patients who reach the individualised T2DM treatment targets (blood
pressure, total cholesterol, HbA1C, weight and smoking status).

Cluster-randomised controlled trial, with randomisation at practice level (and
not single patient randomisation).

In the intervention group (with the SDM approach) patient and GP use a decision
aid to discuss the pros and cons of two evidence based treatment possibilities:
treatment according to the Dutch College of General Practitioners (NHG)
guideline, versus the intensive ADDITION guideline. The patient then shared his
preferences for treatment and responsibility, and informs the GP about his
lifestyle habits and other relevant issues for the decision. Next patient and
GP together choose one of these treatments, based on the facts and preferences.
Next they arrange the five treatment goals (blood pressure, total cholesterol,
HbA1C, weight and smoking status) in orde of priority. Subsequent treatment
will take place according to these OPTIMAAL priorities. The priorities will be
evaluated every 12 months.

Burdens of this study could be the questionnaires that will be have to be
filled out by the patients (completion will take approximately 20-30 minutes).
We acknowledge the time burden this may impose on the patient. We expect SDM
itself to be without direct risk for the patient. We judge the time burden to
be in proportion with the study duration of three years, because all other
appointments will be integrated in usual care visits. Expected benefits are
increased responsibility of patients in their disease decisions, which may lead
to an increased involvement, satisfaction and empowerment of the patient, and
the possible benefits for the diabetes care in the Netherlands.