Factors related to medication adherence in patients with hypertension in Iran: a systematic review study

This study aimed to review the available studies of the factors in Iranian hypertensive patients' adherence to drug treatment.

Four Persian databases and seven English databases were searched. The articles, which were published from 2000 to 2022 in Persian and English and examined the adherence to drug treatment in the Iranian population of adults with high blood pressure, were reviewed. Based on the primary examination, 31 of the initial 1062 articles met the inclusion criteria and were included in the analysis. The evidence, which was provided by the examined articles, was summarized and discussed using the 5-dimensional framework of adherence to long-term treatments, which was developed by WHO.

The factors that significantly correlated with adherence to drug treatment in the examined studies were: (1) factors that were related to the health team or the health system: patients' satisfaction with their doctor-patient relationship; (2) factors that were related to the conditions: the number of concomitant diseases, high quality of life and the implementation of effective interventions; (3) factors which were related to the treatment: long duration of illness, short intervals between the visits, duration of treatment, lower numbers of drugs, and the patient's blood pressure control; and (4) factors that were related to the patient: self-efficacy, health literacy, social support, locus of control, illness perception, beliefs, attitude, knowledge, and cues to action.

It is possible to draw definite conclusions about the factors which affect adherence to drug treatment in patients with high blood pressure because most of the relevant studies have been cross-sectional. Therefore, in the future, valuable results can be obtained by conducting more studies that preferably use objective instruments for assessing adherence to drug treatment.