Importance of medication adherence and factors affecting it

Non-adherence leads to considerable morbidity, mortality and avoidable health care costs. adherence averages to only 50 % in patients suffering from chronic medical illness. Often, adherence and compliance are used interchangeably. Several determinants have been reported to influence adherence, like nature and duration of therapy, characteristics of disease, side-effects of medication, treatment cost, characteristics of health service facilities, the relation between the physician and patient, patient characteristics, patient's perspective about the illness and therapy. The determinants of non-adherence according to World Health Organization (WHO) are categorized into five factors: socioeconomic, health system-related, therapy-related, condition-related and patient-related. Issues associated with medication non-adherence, which are diverse and complex have been extensively researched for decades and are documented well throughout the literature. In light of this, our study is focused specifically on providing an overview of factors affecting adherence and commonly used measures of medication adherence.