Determinants of Primary Healthcare Utilization among Border Residents in Thailand: A Cross-Sectional Study

Objective: To examine the demographics, attitudes, subjective norms, and perceived behavioral control (PBC) associated with the intention to seek and utilize primary healthcare in Thailand’s border areas.Materials and Methods: A cross-sectional study was conducted from July to September 2025 among primary healthcare users in six border districts of Ubon Ratchathani Province. Using multistage sampling, 580 participants were recruited. Data were collected through a structured questionnaire assessing sociodemographic characteristics, Theory of Planned Behavior (TPB) constructs, intention to use primary healthcare (PHC) services, and self-reported utilization. Data were analyzed by using descriptive statistics, chi-square tests, negative binomial regression, and multivariate linear regression.Results: Most participants were female (82.1%) and covered under the Universal Coverage Scheme (UCS) (90.9%). PBC had the highest mean score among TPB constructs (4.10±0.76) and was significantly associated with both past PHC utilization (IRR=1.27, 95%CI=1.01–1.60, p-value=0.043) and future PHC intention (β=0.27, 95% CI=0.52–1.59, p-value<0.001). Chronic disease status and shorter travel time were also significantly associated with past utilization. In addition, ages 40–59 years, marital status, and insurance type were associated with future PHC intention. Beneficiaries of the UCS reported a higher intention to seek care at sub-district health-promoting hospitals (p-value<0.001).Conclusion: PBC, travel time, and chronic disease were associated with PHC utilization. These findings suggest that improving accessibility, strengthening primary care pathways, and supporting confidence in PHC services may be relevant for PHC utilization among border residents, including working-age and married groups.