Introduction:

patients with type 2 diabetes mellitus tend to be poorly adherent to their treatments due to various reasons and factors.

Objectives:

to present prevalence figures of medication non-adherence in patients with type 2 diabetes mellitus, its associated factors and the most frequently used instruments in the evaluation of this construct.

Methods:

a systematic review, whose search criterion was medication adherence in patients with type 2 diabetes mellitus, was carried out. Electronic databases such as EBSCO, PubMed, SciELO, Dialnet, ScienceDirect and Google Scholar were consulted. Articles published in peer-reviewed scientific journals, in Spanish, English and Portuguese languages from 2016 onwards were the established inclusion criteria, as well as intervention studies and those that evaluated the medication adherence in patients with diabetes mellitus together with other chronic diseases were the exclusion criteria.

Conclusions:

adherence to pharmacological treatment in patients with type 2 diabetes mellitus is more adequate than non-pharmacological ones. Its evaluation is carried out, fundamentally, through validated tests, where Morisky-Green was the most used test. In the cited studies, medication non-adherence is associated with sociodemographic and socioeconomic factors, related to the complexities of the treatment, with the disease, with difficulties in the doctor-patient relationship and with the presence of negative emotional states. Subjective and behavioral factors such as self-efficacy, self-control and self-regulation have been little studied.