Tsukada Yoichiro, Nakamura Fumiaki, Iwamoto Momoko, Nishimoto Hiroshi, Emori Yoshiko, Terahara Atsuro, Higashi Takahiro
Division of Health Services Research, Center for Cancer Control and Information Services, National Cancer Center, Tokyo Department of Radiology, Toho University Omori Medical Center, Tokyo
Department of Public Health/Health Policy, Graduate School of Medicine, The University of Tokyo, Tokyo.
Jpn J Clin Oncol. 2015 Aug;45(8):719-26. doi: 10.1093/jjco/hyv069. Epub 2015 May 15.
Differences in hospital case-mix have not been adequately accounted for in hospital volume and patient outcome studies in Japan. We aimed to examine whether differences may exist by investigating the distribution of patients' stage and age across designated cancer treatment hospitals of varying patient volume across Japan.
We analyzed data of gastric, breast, colorectal, lung and liver cancer patients who were included in the national database of hospital-based cancer registries between 2008 and 2011. We investigated the association between hospital volume, cancer stage and patient age. Hospitals were classified into five groups according to patient volume.
In total, 676 713 patients met the inclusion criteria. The proportion of patients with early-stage (tumor-node-metastasis Stage 0 or I) cancer was higher among high-volume hospitals for all cancer types except small cell lung cancer. The proportion of older patients (age >75 years) was smaller among high-volume hospitals for all cancer types. The difference in the proportion of patients with early-stage cancers between very low-volume and very high-volume hospitals was greatest for non-small cell lung cancer (26.5% for very low and 43.5% for very high). This difference for the proportion of older patients was also greatest for non-small cell lung cancer (48.9% for very low and 30.3% for very high).
We showed that the proportions of early-stage cancer patients and younger patients are greater in higher-volume hospitals compared with lower-volume hospitals in Japan. Researchers conducting volume-outcome studies and policymakers analyzing hospital performance should be cautious when making interhospital comparisons.
在日本，医院病例组合的差异在医院规模和患者结局研究中尚未得到充分考量。我们旨在通过调查日本不同患者规模的指定癌症治疗医院中患者分期和年龄的分布情况，来研究是否存在差异。
我们分析了2008年至2011年纳入全国医院癌症登记数据库的胃癌、乳腺癌、结直肠癌、肺癌和肝癌患者的数据。我们研究了医院规模、癌症分期和患者年龄之间的关联。医院根据患者规模分为五组。
共有676713名患者符合纳入标准。除小细胞肺癌外，所有癌症类型中，高规模医院早期（肿瘤-淋巴结-转移0期或I期）癌症患者的比例更高。所有癌症类型中，高规模医院老年患者（年龄>75岁）的比例更小。极低规模医院和极高规模医院之间早期癌症患者比例的差异在非小细胞肺癌中最大（极低规模医院为26.5%，极高规模医院为43.5%）。老年患者比例的这种差异在非小细胞肺癌中也最大（极低规模医院为48.9%，极高规模医院为30.3%）。
我们发现，与日本低规模医院相比，高规模医院中早期癌症患者和年轻患者的比例更高。进行规模-结局研究的研究人员和分析医院绩效的政策制定者在进行医院间比较时应谨慎。
