Posters advertising the study and leaflets containing study information will be available in the general waiting areas of the health centre. Adult patients attending the medical outpatients department or one of the chronic disease clubs will be approached and invited to consider taking part in the study. Interested individuals will have the opportunity to ask trained research staff questions about the study and their participation. Information about the study will be available in English, isi-Xhosa, and Afrikaans. Individuals interested in participating will be asked a series of screening questions to assess their eligibility for inclusion in the study and will have their blood pressure measured as per the study protocol. Eligible participants who decline to participate will be asked for permission to access their clinical record to extract basic details (age, gender, medication, recent blood pressure). Copies of Participant Information Leaflets and posters in English can be found in Appendix B. Translated copies are available upon request.