Knowledge about the process of use of antihypertensive medications and its relationship with adherence

Introduction: Adherence to antihypertensive medication (Adh-MHBP) is influenced by the patient’s knowledge about high blood pressure (HBP) and the medications prescribed to treat it. Few studies have evaluated how patient knowledge influences the process of using antihypertensive medications (CUMA) in Adh-MHBP. The objective was to evaluate the relationship between CUMA and Adh-MHBP, and to propose a questionnaire to measure CUMA (CUMA-Q). Method: A cross-sectional descriptive observational study was carried out on 95 patients who came to pick up their antihypertensive medication (MHBP) at 5 community pharmacies in the metropolitan area of Granada (Spain). The percentage of adherence to MHTA (%Adh-MHBP) was calculated based on the dispensing record of the electronic prescription system (SPE) of the Andalusian Health System (SAS). A multivariate logistic regression was performed to study the relationship between CUMA and Adh-MHBP. The validity and reliability of CUMA-Q was studied. Results: 95 patients were included (56.8 % women). The mean age was 68.1 (SD: 10.0) years. Only 17.9% had a BMI <25kg/m2. Considering a minimum %Adh-MBHP of 80 %, 30.5 % were non-adherent. The multivariate analysis showed that there was a greater risk of being non-adherent if the process of using the medication is not known in a statistically significant way. Conclusions: This study shows that if the patient knows how to identify their MHTA and knows the prescribed dosage and guidelines, it is more likely that their adherence to said medication will be adequate. The CUMA-Q presented acceptable psychometric properties in the sample studied.