Few studies have explored how specific formats of effectiveness information effect on real patients' decisions. We only know little about what kind of format would be the optimal to help patients make well-informed real-life decisions corresponding to their preferences.

The trial is developed in a clinical randomised design to study risk communication in the shared decision making between general practitioners (GP) and their patients in primary prevention with of cholesterol lowering drug. Endpoints are effect of GPs' information about treatment effectiveness and their patients' values on patients' tendency to accept and adhere to the treatment as well as their feeling of content with the choice made. GPs are randomised to inform about risk and treatment effectiveness by means of either absolute risk reduction (ARR) or Prolongation of Life (POL). Afterwards patients are invited to answer questionnaires concerning their content with decisions and reflections. Patients' redemption of prescriptions during the following week and the first year are recorded through an electronic database.

57 GPs and 248 patients have been enrolled in the trial.

As chronic diseases are steadily increasing in the industrialized countries, there is a growing focus on preventive initiatives. This means that risk communication between the physician and his patients plays a central role.

Effective risk communication can enhance knowledge, involvement in decisions about tests or treatment, autonomy and empowerment of patients. Poor communication, however, can lead to anxiety, lack of confidence in health care professionals, and other adverse outcomes. It is vital that we identify the available evidence about how it should best be done.

The standard formats used to communicate intervention effectiveness are absolute risk reduction, relative risk reduction, number needed to treat, and life prolongation of life.

Few studies have explored the formats' influence on real patient decisions, implying that we only know little about what kind of format would be the optimal to help patients make well-informed real-life decisions corresponding to their preferences.

In a clinical randomized design risk communication is studied in the preventive talk between the general practitioner (GP) and his patients concerning cardiovascular diseases. Special focus is on influence of information format on patients' choice of therapy, adherence to therapy and satisfaction with therapy.

GPs are randomized to one of two groups, being taught in informing their patients by means of either absolute risk reduction, ARR or life extension, LE.

The setting is the preventive talk in the GP's clinic. From a measured total-cholesterol the GP informs his patient about the individual risk of getting a cardiovascular disease and the possible effectiveness of a cholesterol-lowering drug. This is done by means of either ARR or LE. After the talk the patient is invited to answer a questionnaire concerning personal experience with the information given (deadline 2 weeks after the talk), and again after 3 months will receive a questionnaire concerning satisfaction with the decision made and reflections. Patients' redemption of prescriptions during the following week and the first year are recorded through Odense PharmacoEpidemiological Database, OPED. The GPs' opinions, experiences and concerns about risk communication, prevention, and usage of statins are explored by means of questionnaires.

Inclusion Criteria:

• 40-69 year-olds
• Patients with a measured total-cholesterol of > 4 MMol/Litre

Exclusion Criteria:

• Patients with diabetes
• Patients with known chronic cardiovascular diseases
• Patients who are already being treated with cholesterol lowering therapy
• Patients who are not familiar with the danish language