Evaluation of adherence to pharmacological treatments by undocumented migrants with chronic diseases: a 10-year retrospective cohort study

Objectives To investigate the time course of medication adherence and some of the factors involved in this process in undocumented migrants with chronic diseases.Design Retrospective cohort study.Setting A big non-governmental organisation in Milano, Italy, giving medical assistance to undocumented migrants.Participants 1918 patients, 998 females and 920 males, with at least one chronic condition (diabetes, cardiovascular diseases (CVDs), mental health disorders) seen over a period of 10 years (2011–2020). Their mean age was 49.2±13 years.Results Adherence to medications decreased over 1 year in all patients. This was more evident during the first 2 months of treatment. Patients on only one medication were less adherent than those on more than one medication; at 6 months the percentage of patients with high adherence was 33% vs 57% (p