Heterogeneity Among Patients Discontinuing Medical Nutrition Therapy in Primary Care: A Latent Class Analysis

Background Medical nutrition therapy (MNT) is a key component of chronic disease management in primary care and is effective in managing noncommunicable diseases (NCDs), obesity, and malnutrition; however, discontinuation is common in routine clinical practice. While previous studies have examined individual factors associated with discontinuation, MNT disengagement likely reflects heterogeneous background patterns shaped by the interplay of multiple factors. From a primary care perspective emphasising comprehensiveness and continuity, this study aimed to identify heterogeneity among patients who discontinue MNT. Methods This retrospective observational study was conducted at a primary care clinic in Japan. Outpatients who received dietitian-led MNT and subsequently discontinued therapy between January 2019 and December 2024 were included (n = 332). Latent class analysis (LCA) using maximum likelihood estimation was conducted on categorical variables representing demographic characteristics, clinical factors, lifestyle behaviours, and psychosocial factors. The optimal model was selected based on information criteria, classification accuracy, and clinical interpretability. Results The final analytical sample comprised 300 patients. LCA identified four distinct subgroups with differing background patterns. These subgroups broadly reflected patterns involving older adults with relatively preserved self-care; working-age individuals with low clinical and lifestyle risk; individuals with high BMI and coexisting medical conditions receiving pharmacotherapy; and individuals exhibiting prominent lifestyle risk behaviours and low illness awareness. Conclusions Discontinuation of MNT was not attributable to a single determinant but reflected diverse, multifactorial background patterns encompassing demographic, clinical, behavioural, and psychosocial characteristics. These findings provide a foundation for developing tailored strategies to support sustained engagement with MNT in primary care, grounded in comprehensive patient profiling.