Adverse drug events (ADEs) are responsible for 3.6% of the hospitalisations in France. 50% of these ADEs could be preventable. Cardiovascular drugs are frequently involved in ADEs. A common underlying factor of such events is inadequate communication between patients and medical personnel. General practitioners (GP) often initiate the treatment of hypertension, being generally the first prescribers of these medications. 12.6% of the patients present an ADE with hypertensive drug after 3 months. The InPAct procedure is a tool to facilitate communication in order to improve patient safety in primary care. In the context of the primary care prescription of an antihypertensive drug, the GP informs the patient about hypertension, cardiovascular risk, and the benefits and risks of antihypertensive drugs, which helps the patient to detect and declare situations involving a heightened risk of antihypertensive-related ADEs. The aim of the InPAct study is to evaluate the efficiency of the InPAct intervention in primary care.

A stepped wedge cluster randomized study, with 8 clusters and 5 periods of 3 months each. Each cluster is composed of about ten general practitioners. The InPAct intervention will not be presented to the first patients recruited by each general practitioner, whereas it will be presented to all their last patients. The period of intervention introduction by each general practitioner will be randomized amongst the 5 periods.

Inclusion Criteria:

• Patient monitored for essential hypertension requiring a first prescription, a renewal or a change of antihypertensive drug treatment
• Patient with the ability to understand and express themselves in French
• Patient accepting to communicate his phone number and accepting a telephone survey within the fourth month following its inclusion in the study.

Exclusion Criteria :

• Patient with a psychiatric disorder or a progressive dementia.
• Patient with hypertension in pregnancy or secondary hypertension.
• Patient with an acute hypertensive crisis.
• Patient under guardianship.
• Patient who is likely to move or may have an irregular follow up within 6 months following its inclusion in the study.

Hypertensive patients on anti-hypertensive medication. Patients of 85 general practitioners selected in Rhone-Alps/Auvergne and Paris region in France.