Abstract
<title>Abstract</title> <p>Background Diabetes mellitus is a chronic metabolic disorder characterised by persistent hyperglycaemia. Its prevalence is increasing in Nepal, posing a substantial public health challenge. Poor treatment adherence leads to uncontrolled blood glucose, diabetes-related complications, and an increased healthcare burden. This study aimed to assess the level of treatment adherence and to identify its associated factors among patients with type 2 diabetes mellitus attending a tertiary care hospital in Nepal. Methods A hospital-based cross-sectional study was conducted among 410 outpatients with type 2 diabetes mellitus attending Lumbini Provincial Hospital, Butwal, Nepal, between December 2022 and March 2023. Participants were recruited by non-probability consecutive sampling. Treatment adherence was measured using the validated Brief Medication Questionnaire. Sociodemographic, behavioural and clinical data were collected through structured interviews. Associations were examined using chi-square tests, and independent predictors of non-adherence were identified using binary logistic regression. Results Only 30.0% of participants were adherent to their prescribed treatment regimen; 70.0% were non-adherent. Age (χ² = 8.986; p = 0.029) and presence of comorbidities (χ² = 6.646; p = 0.010) were significantly associated with adherence on bivariate analysis. Glycated haemoglobin (HbA1c) level showed a borderline non-significant trend (χ² = 3.152; p = 0.076). On multivariable logistic regression, age remained the only independent significant predictor of non-adherence. Lifestyle factors and clinical symptoms showed no statistically significant association with adherence. Conclusions Treatment non-adherence is highly prevalent among patients with type 2 diabetes mellitus attending a tertiary care hospital in Nepal. Age-targeted and glycaemia-informed patient education, structured counselling and family engagement are needed to improve adherence and optimise diabetes outcomes.</p>