Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, Johns Hopkins Hospital, Baltimore, MD.
Division of Vascular Surgery, Johns Hopkins Bayview Medical Center, Baltimore, MD.
Ann Vasc Surg. 2021 Jan;70:190-196. doi: 10.1016/j.avsg.2020.07.011. Epub 2020 Jul 29.
Local market competition has been previously associated with more aggressive surgical decision-making. For example, more local competition for organs is associated with acceptance of lower quality kidney offers in transplant surgery. We hypothesized that market competition would be associated with the size of an abdominal aortic aneurysm (AAA) at the time of elective endovascular aneurysm repair (EVAR).
We included all elective EVARs reported in the Vascular Quality Initiative database (2012-2018). Small AAAs were defined as a maximum diameter <5.5 cm in men or <5.0 cm in women. We calculated the Herfindahl-Hirschman Index (HHI), a measure of physician market concentration (higher HHI = less market competition), for each US census region. Multilevel regression was used to examine the association between the size of AAA at EVAR and HHI, clustering by region.
Of 37,914 EVARs performed, 15,379 (40.6%) were for small AAAs. There was significant variation in proportion of EVARs performed for small AAAs across regions (P < 0.001). The South had both the highest proportion of EVARs for small AAAs (44.2%) as well as the highest market competition (HHI 50), whereas the West had the lowest proportion of EVARs for small AAAs (35.0%) and the lowest market competition (HHI 107). Adjusting for patient characteristics, each 10 unit increase in HHI was associated with a 0.1 mm larger maximum AAA diameter at the time of EVAR (95% CI 0.04-0.24 mm, P = 0.005).
Physician market concentration is independently associated with AAA diameter at time of elective EVAR. These data suggest that physician decision-making for EVAR is impacted by market competition.
先前的研究表明，当地市场竞争与更激进的手术决策有关。例如，器官的竞争加剧会导致在移植手术中接受质量较低的肾脏捐赠。我们假设市场竞争与择期血管内修复术（EVAR）时腹主动脉瘤（AAA）的大小有关。
我们纳入了血管质量倡议数据库（2012-2018 年）中报告的所有择期 EVAR。小 AAA 定义为男性最大直径<5.5cm 或女性<5.0cm。我们计算了每个美国普查区域的赫芬达尔-赫希曼指数（HHI），这是一种衡量医生市场集中程度的指标（HHI 越高，市场竞争越小）。多水平回归用于检查 EVAR 时 AAA 大小与 HHI 之间的关联，按区域进行聚类。
在 37914 例 EVAR 中，有 15379 例（40.6%）用于小 AAA。不同区域 EVAR 治疗小 AAA 的比例存在显著差异（P<0.001）。南部的 EVAR 治疗小 AAA 的比例最高（44.2%），市场竞争也最高（HHI 为 50），而西部的 EVAR 治疗小 AAA 的比例最低（35.0%），市场竞争也最低（HHI 为 107）。调整患者特征后，HHI 每增加 10 个单位，EVAR 时最大 AAA 直径就会增加 0.1mm（95%CI 0.04-0.24mm，P=0.005）。
医生市场集中程度与择期 EVAR 时的 AAA 直径独立相关。这些数据表明，医生在 EVAR 决策中受到市场竞争的影响。
