Yip W, Luft H S
Institute for Health Policy Studies, University of California, San Francisco 94109.
Soc Sci Med. 1993 Jun;36(11):1455-65. doi: 10.1016/0277-9536(93)90387-j.
A major concern of researchers using state data sets for population-based analyses and market share studies in the health care sector is the potential bias caused by 'border crossing'--patients receiving care out of state. By using the Health Care Financing Administration (HCFA) discharge abstract files for 1987 and 1988, we found that 'border crossing' is not a serious problem for the two large states we examined. Only 4.4% of New York patients and 2.15% of California patients received care out of state. At the county and zip code level, 'border crossing' is more frequent but tends to be concentrated in areas adjacent to other states. Even excluding all zips with more than 10% of patients crossing the 'border' results in a small loss of patients (2.2% for New York and 1.0% for California).
在医疗保健领域，使用州数据集进行基于人群的分析和市场份额研究的研究人员主要关注的一个问题是，“跨界就医”——患者在州外接受治疗——可能导致的偏差。通过使用1987年和1988年医疗保健财务管理局（HCFA）的出院摘要文件，我们发现，对于我们所研究的两个大州来说，“跨界就医”并非严重问题。只有4.4%的纽约患者和2.15%的加利福尼亚患者在州外接受治疗。在县和邮政编码层面，“跨界就医”更为频繁，但往往集中在与其他州相邻的地区。即使排除所有有超过10%的患者“跨界”的邮政编码地区，患者数量的损失也很小（纽约为2.2%，加利福尼亚为1.0%）。
