Adherence of patients to long-term medication: a cross-sectional study of antihypertensive regimens in Austria

Abstract

Objective The objective of this study was to evaluate adherence and causes for non-adherence to antihypertensive therapy in Austrian patients. A special focus was placed on social parameters and behavioural theories. Methods Patients were invited via advertisements in community pharmacies in Austria to complete an online survey. Inclusion criteria were an age of 18 years or older, a diagnosis of arterial hypertension and a current prescription of antihypertensive medication. Adherence was measured by the four-item Morisky scale. Non-adherence was defined by at least one point in the Morisky scale. Several demographic, social and behavioural parameters were analysed as potential co-variables associated with adherence. Results A total of 323 patients completed the online survey, of which 109 (33.7 %) met the criteria for nonadherence. In a multivariable model, self-efficacy and age were associated with adherence, whereas intention and barriers were linked to non-adherence; 56 patients (17.3 %) were classified as intentionally non-adherent. Conclusion This study demonstrates that non-adherence affects an important proportion of patients in the treatment of arterial hypertension. Young age was a particularly important risk factor for non-adherence, and this patient population is, therefore, in need of special attention. Modifiable risk factors were identified that could help improving the treatment of arterial hypertension and potentially other chronic conditions.