- 著者
- Madoka Iwase Yukari Taniyama Yuriko N. Koyanagi Yumiko Kasugai Isao Oze Norikazu Masuda Hidemi Ito Keitaro Matsuo
- 出版者
- Japan Epidemiological Association
- 雑誌
- Journal of Epidemiology (ISSN:09175040)
- 巻号頁・発行日
- pp.JE20230155, (Released:2024-01-06)
- 参考文献数
- 30
Background: Reproductive factors such as age at menarche are known to be associated with disease risk, but data on trends in these factors in Japan are limited. In this study, we investigated secular trends in reproductive factors and explored their potential association with socioeconomic and historical events.Methods: We conducted a retrospective analysis of 62,005 Japanese women born between 1890 and 1991 using a survey conducted over 25 years. Trends in reproductive factors were analyzed using linear and joinpoint regression models, and their associations with major historical events involving Japan were evaluated.Results: We found that the age at menarche showed a significant downward trend (P-value<0.001) over the century. Three joinpoints were identified, in 1932 (15.23 years old), 1946 (13.48 years old), and 1959 (12.71 years old), which indicated that average age at menarche decreased by approximately 0.8% per year between 1932 and 1946, and then by 0.4% per year between 1946 and 1959, both of which were statistically significant. However, after 1959, age of menarche remained stable. Analyses of other reproductive factors found significant changes, including a decrease in parity and the number of babies breastfed, and an increase in age at first birth.Conclusion: Age at menarche showed a long-term downward trend in Japan, with significant change points in annual percent change. Other factors showed secular changes in trends as well. These change points were observed at the same time as historical events, namely wars and economic development, suggesting that socioeconomic and environmental changes at the population level affect reproductive factors in females.
- 著者
- Yukari Taniyama Takahiro Tabuchi Yuko Ohno Toshitaka Morishima Sumiyo Okawa Shihoko Koyama Isao Miyashiro
- 出版者
- Japan Epidemiological Association
- 雑誌
- Journal of Epidemiology (ISSN:09175040)
- 巻号頁・発行日
- pp.JE20190242, (Released:2020-01-11)
- 参考文献数
- 30
- 被引用文献数
- 6
Background: The impact of hospital surgical volume on long-term mortality has not been well assessed in Japan, especially for esophageal, biliary tract, and pancreatic cancer, although these three cancers need a high-level of medical technical skill. The purpose of this study was to examine associations between hospital surgical volume and 3-year mortality for these severe prognosis cancer patients.Methods: Patients who received curative surgery for esophageal, biliary tract, and pancreatic cancers were analyzed using Osaka Cancer Registry data from 2006-2013. Hospital surgical volume was categorized into tertiles (high/middle/low) according to the average annual number of curative surgeries per hospital for each cancer. Three-year survivals were calculated using the Kaplan-Meier method. Hazard ratios (HRs) of 3-year mortality were calculated using Cox proportional hazard models, adjusting for patient characteristics.Results: Three-year survival was higher with increased hospital surgical volume for all three cancers, but the relative importance of volume varied across sites. After adjustment for all confounding factors, HRs (95% Confidence interval [CI]) in middle- and low-volume hospitals were 1.34 (95% CI, 1.14-1.58) and 1.57 (95% CI, 1.33-1.86) for esophageal cancer; 1.39 (95% CI, 1.15-1.67) and 1.57 (95% CI, 1.30-1.89) for biliary tract cancer; 1.38 (95% CI, 1.16-1.63) and 1.90 (1.60-2.25) for pancreatic cancer, respectively. In particular localized pancreatic cancer, the impact of hospital surgical volume on 3-year mortality was strong (HRs: 2.66 [95% CI, 1.61-4.38]).Conclusion: We suggest that patients who require curative surgery for esophageal, biliary tract, and pancreatic cancer may benefit from referral to high-volume hospitals.