Hypertension is a major risk factor for stroke, ischaemic heart disease, and kidney disease. One major cause for uncontrolled blood pressure in spite of prescribed pharmacotherapy was found to be non-adherence including erratic use of prescribed medication.

General practitioners (GP) face limitations when a guideline-conform therapy fails. A new tool to measure and assess medication adherence could be useful to identify patients who are not using medicine as prescribed. This provides new opportunities for patient-specific recommendations and adjustments of treatment.

Our aim is to assess the usefulness of the adherence package AMoPac to identify non-adherence in hypertensive patients nonresponding to treatment in daily practice.

Patients with hypertension are usually asymptomatic and do not feel an immediate benefit when taking their medication. This can result in early treatment interruption, omitted doses or drug holidays. Especially when side effects occur, which is often reported for diuretics and ACE inhibitors, patients tend to take their medicines less regularly or even to omit them. Furthermore, it is known that adherence decreases with the increased number of daily medicines. Patients with polypharmacy are thus particularly affected by non-adherence, that is almost inevitable in hypertensive treatment using dual, triple or quadruple therapy. Erratic use of prescribed medication including non-adherence is a major cause for uncontrolled blood pressure. However, practical and reliable methods are missing to screen patients for non-adherence.

The investigators have developed the adherence monitoring package (AMoPac) to help identifying non-adherence in ambulatory hypertensive patients. AMoPac is a tool that consists of an electronic monitoring device (Time4Med™ or smart phone application), data management and data analysis, feedback on patient's performance and clinical-pharmaceutical evaluation of medication adherence. The purpose is to transmit a patient-specific adherence report (including adherence recommendations) to the the GP.

This study is a prospective, observational study. GPs will recruit hypertensive patients during their routine visits. Patients will monitor daily medication intake at home for 4 weeks. A pharmacist will visit the patient at home to download the adherence data and to give feedback. The patient will then visit the GP who will have already received the adherence report and will have the opportunity to intervene, for example by adapting the patient's treatment or their medication use behavior. The 4-weeks cycle of adherence monitoring can be repeated if needed.

The investigators expect that AMoPac is useful for GPs to identify non-adherence in hypertensive patients nonresponding to treatment.

Inclusion Criteria:

Patients with the following inclusion criteria will be recruited:

• is ≥18 years old;
• is diagnosed with arterial hypertension;
• is prescribed at least 1 antihypertensive medication;
• self-administers medication;
• is suspected of a deviant medication intake behavior (non-adherence) e.g., because of insufficiently controlled blood pressure in spite of prescribed pharmacotherapy (nonresponding);
• accepts to use of an electronic monitoring device during the study period (either the Time4Med™ device or the monitoring app busybee™);
• signs the informed consent form;
• understands and speaks German.

Patients who are using a pillbox, an app or reminders for medication management will not be excluded.

Exclusion Criteria:

Patients who are, in the opinion of the GP, unlikely to comply with the study schedule or are unsuitable for any other reason will be excluded.

hypertensive patients nonresponding to pharmacotherapy