Time to Discontinuation and Risk Factors for Outpatient Medical Nutrition Therapy in Primary Care: A Retrospective Cohort Study Using Survival Analysis

Abstract

Background

Medical nutrition therapy (MNT) provided by registered dietitians is effective for managing non-communicable diseases, but patient discontinuation remains common in clinical practice. Studies examining the timing and predictors of MNT discontinuation are limited. This study aimed to identify the timing and patient factors associated with MNT discontinuation in primary care settings.

Methods

This single-center retrospective cohort study included patients who initiated outpatient MNT at a primary care clinic between April 2018 and March 2023. Patients aged < 18 years and those with cancer- or malnutrition-related conditions were excluded. Discontinuation was defined as no MNT visit or scheduled appointment within 3 months after the last visit. Patients were followed for up to 24 months through March 2025. Kaplan–Meier analysis estimated continuation rates, and multivariable cause-specific Cox proportional hazards models identified factors associated with discontinuation. Multiple sensitivity analyses were performed.

Results

Among 470 patients (median age, 63 years; 59.4% women), 241 (51.3%) discontinued MNT during follow-up. Median time to discontinuation was 15 months (95% confidence interval [CI], 12–21). Continuation rates were 88.3% at 3 months, 70.4% at 6 months, and 43.5% at 24 months. Obesity, dyslipidemia, and medication use were associated with lower discontinuation risk, whereas complications, living with family, and preparation stage of behavior change were associated with higher risk. Sensitivity analyses confirmed the robustness of the results.

Conclusions

MNT continuation declined rapidly within 6 months. Multiple patient factors were associated with discontinuation risk, suggesting the need for early risk identification and individualized support strategies.