Correlation between Usual Source of Care and Medication Adherence in Patients with Hypertension

Maintaining a usual source of care (USC), which is crucial for primary healthcare, encompasses initial contact, comprehensive services, coordinated care, and ongoing support. However, limited research exists on the relationship between USC and medication adherence in patients with hypertension. This study aimed to investigate the association between USC and medication adherence among patients with hypertension.

Data from the 2nd Korea Health Panel Survey 2020 were analyzed. The final sample consisted of 3,318 participants aged 19 years or older diagnosed with hypertension. USC was categorized into three groups: no USC, place only (without a regular doctor), and regular doctor. Medication adherence was assessed using detailed items (dose, frequency, time, no stop) and a 4-point Likert scale. A logistic regression analysis was conducted with control for relevant variables.

Compared to the no USC group, the regular doctor group had significantly higher odds ratios (ORs) for overall perfect/high medication adherence rates: 1.70 (95% confidence interval [CI], 1.42-2.03) and 1.59 (95% CI, 1.14-2.20). Similar results were observed for each adherence item, including prefect dose (OR, 2.14; 95% CI, 1.73- 2.63), frequency (OR, 1.87; 95% CI, 1.53-2.28), time (OR, 1.72; 95% CI, 1.43-2.07), and no stop (OR, 1.56; 95% CI, 1.09-2.23)/high frequency (OR, 2.47; 95% CI, 1.21-5.01), time (OR, 2.30; 95% CI, 1.19-4.44). However, the place only group showed no significant differences in medication adherence except for perfect adherence to dose (OR, 1.35; 95% CI, 1.06-1.71).

These findings provide evidence supporting the need for healthcare policies that encourage having a regular doctor in South Korea, which has a healthcare system with limited primary care.