Objective: To investigate medication adherence among patients with and without medication subsidies and to identify factors that may influence patients' adherence to medication. Setting: Government healthcare institutions in Kuala Lumpur, Selangor, and Negeri Sembilan and private healthcare institutions in Selangor and Negeri Sembilan, Malaysia.

Methods: This cross-sectional study sampled patients with and without medication subsidies (self-paying patients). Only one of the patient's medications was re-packed into Medication Event Monitoring Systems (MEMS) bottles, which were returned after four weeks. Adherence was defined as the dose regimen being executed as prescribed on 80% or more of the days. The factors that may influence patients' adherence were modelled using binary logistic regression. Main outcome measure: Percentage of medication adherence.

Results: A total of 97 patients, 50 subsidized and 47 self-paying, were included in the study. Medication adherence was observed in 50% of the subsidized patients and 63.8% of the self-paying patients (χ2=1.887, df=1, p=0.219). None of the evaluated variables had a significant influence on patients' medication adherence, with the exception of attending drug counselling. Patients who attended drug counselling were found to be 3.3 times more likely to adhere to medication than those who did not (adjusted odds ratio of 3.29, 95% CI was 1.42 to 7.62, p = 0.006).

METHODS: Subsidised and self-paying patients were identified at public and private healthcare institutions in three states of Malaysia. Patients were then purposively selected for semi-structured, face-to-face interviews according to their medication adherence status (including adherent and non-adherent patients), which was measured using the Medication Event Monitoring System (MEMS). Adherence was defined as having 80% or more for the percentage of days in which the dose regimen was executed as prescribed. The interview was conducted from January to August 2016 and during the interviews, patients were asked to provide reasons for their medication adherence or non-adherence. The patient interviews were audio recorded and transcribed verbatim. Data were analysed using thematic analysis with NVivo 11 software.

RESULTS: Thirteen subsidised and 12 self-paying patients were interviewed. The themes found among subsidised and self-paying patients were similar. The factors that influenced adherence to medication include the 'perceived importance of quality of life' and 'perceived benefit or value of the medications'. A unique factor reported by patients in this study included 'perceived value of the money spent on medications'; more specifically, patients adhered to their medications because they valued the money spent to buy/receive the medications.