目標：就醫地理可近性差異，可能導致就醫選擇不同，進而影響治療的內容、品質及結果。透過就醫流向，可深入探討其影響因素。本研究從地理可近性的觀點，分析肝癌病患的就醫選擇。方法：利用地理資訊系統與癌症診療資料庫，建立2004年罹患肝癌病患之首次就醫醫院網絡，分析就醫地理可近性與病患就醫流向的地理關聯。結果：大部分病患選擇在最近可就醫區內就醫。28.3%跨區就醫的病患中，在年齡與性別上無顯著差異；初期癌症有較高的比例跨區就醫(31.2%)。跨區就醫比例較高的區域特性包括：最近可就醫區內無醫學中心(59.1%)、醫院越少及跨區就醫增加交通時間越少。跨區就醫病患有更高的比例選擇醫學中心級醫院。而就醫地理可近性最差等級的病患，大多在最近可就醫區就醫(86.9%)。結論：本研究有兩個重要發現，肝癌病患居住地最近可就醫區內的醫院數、有無醫學中心及跨區就醫地理障礙明顯影響病患就醫行為；就醫地理可近性等級與跨區就醫病患比例呈現非線性的關係，在可近性最差的地區出現反轉。上述發現，有助我們闡述醫療資源不平等的現象與影響，能進一步分析就醫流向與醫療品質的關係。

Objectives: The distance to hospitals affects a patient's hospital-seeking behavior and results in a variety of patterns of care, treatment quality and outcomes. We attempted to determine the impact of distance by applying the concepts of geographical accessibility. Methods: By using geographic information systems (GIS), we mapped the home townships of patients with hepatocellular carcinoma (HCC) diagnosed in 2004 and the hospitals of their first visit. We then established a patient-hospital network to analyze the association between geographical accessibility to hospitals and the travel patterns of patients. Results: We found that 28.3% of patients chose hospitals far away from their nearest hospitalaccessible area (cross-district). There were no statistically significant differences in age or gender between cross-district and within-district patients. Patients with early stage cancer had significantly more potential than those with late stage cancer to seek cross-district hospitals. We also found that patients with fewer hospitals and no medical centers within their nearest hospital-accessible area, and with shorter distances to access cross-district hospitals, significantly increased cross-district hospitalseeking behavior. They preferred medical centers. Furthermore, a non-linear relationship between geographical accessibility to hospitals and cross-district hospital-seeking behavior was identified. Patients with the greatest difficulty in hospital access tended to choose hospitals nearby. Conclusions: Employing a GIS-based accessibility approach, we found that medical resources within-district and distance to cross-district hospitals significantly affected patients' hospital-seeking behavior. By identifying the non-linear relationship between accessibility to hospitals and patients' cross-district hospital-seeking, this study showed the importance of incorporating spatial inequality into the planning for the provision and utilization of health care. Care patterns, treatment quality and outcomes for cancer hospitals also need to be considered in explaining cross-district hospital-seeking behavior.