# Associations between usual source of care characteristics and health outcomes in diabetes mellitus: a focus on medication adherence and healthy behaviors in Korea

## TL;DR

This study shows that having a regular doctor who provides comprehensive and coordinated care improves medication adherence in Korean adults with diabetes.

## Contribution

The study introduces a categorization of usual sources of care based on primary care functions and links them to medication adherence in diabetes.

## Key findings

- Patients with a regular doctor fulfilling comprehensiveness and coordination functions were more likely to adhere to medication.
- Having a usual source of care alone was not sufficient to improve medication adherence.
- No significant associations were found between usual source of care and healthy behaviors like smoking or exercise.

## Abstract

This study investigated the associations between usual source of care (USC) characteristics, which incorporate primary care functions, and medication adherence and healthy behaviors in Korean adults with diabetes.

We used data from 1,543 adults with diabetes in the 2020 Korea Health Panel Survey. USC was categorized into 5 types based on whether a regular doctor was identified and whether that provider fulfilled comprehensiveness and coordination functions. Multivariable logistic regression was used to assess associations with medication adherence and healthy behaviors.

A significant difference in medication adherence was observed by USC type, although no significant associations emerged for healthy behaviors (smoking, drinking, exercise). Compared to the group without a USC, patients whose regular doctor fulfilled either function were 2.38 times more likely to adhere (odds ratio [OR], 2.38; 95% confidence interval [CI], 1.70 to 3.32), and those whose doctor fulfilled both functions were 1.84 times more likely to adhere (OR, 1.84; 95% CI, 1.31 to 2.59). This association was particularly strong for adherence to medication dosage, frequency, and timing.

The findings underscore that the functional quality of the USC, particularly the fulfillment of comprehensiveness and coordination, is crucial in improving medication adherence. Simply having a USC is insufficient. The lack of association with healthy behaviors suggests that physicians may focus more on pharmacological control, highlighting the need for multifaceted interventions.