Mortality and cancer incidence among physicians of traditional Chinese medicine: a 20-year national follow-up study
- Shu-Hui Liu1,
- Yu-Feng Liu1,
- Saou-Hsing Liou2,
- Yun-Lian Lin3,
- Yuen-Chen Hsiao4,
- Chu-Chieh Chen5,
- Chung-Yi Li5,
- Trong-Neng Wu1,2,6
- 1Institute of Environmental and Occupational Health Sciences, National Yang Ming University, Taipei, Taiwan
- 2Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County, Taiwan
- 3National Research Institute of Chinese Medicine, Ministry of Education, Taipei, Taiwan
- 4Department of Industrial Education, National Taiwan Normal University, Taipei, Taiwan
- 5Department of Health Care Management, National Taipei College of Nursing, Taipei, Taiwan
- 6Department of Public Health and Institute of Environmental Health, China Medical University and Hospital, Taichung, Taiwan
- Correspondence to Dr Trong-Neng Wu, Institute of Environmental Health, College of Public Health, China Medical University and Hospital, 91 Hseuh-Shih Road, Taichung 404, Taiwan;
- Accepted 28 October 2009
Objective To study the risks of mortality and cancer incidence in physicians of traditional Chinese medicine (TCM) who had frequent exposure to herbal medicine.
Methods A population-based cohort design was conducted in which a total of 7675 certified physicians of TCM who ever practised between 1985 and 2005 were compared with the age-, sex- and calendar year-specific mortalities and cancer incidence rates of the general population of Taiwan. The age-, sex- and calendar year-standardised mortality ratio (SMR) and standardised cancer incidence ratio (SIR) were calculated to estimate the relative risks of all causes and site-specific mortality and cancer incidence.
Results Over an up to 20-year observational period, 796 (10.4%) physicians of TCM died, and 279 (3.6%) developed cancer. The study cohort showed a significantly reduced SMR for all-causes mortality (68, 95% CI 63 to 73), and for deaths from infectious (SMR=64), circulatory (SMR=68), respiratory (SMR=64) and digestive (SMR=56) disease. The study cohort also had a significantly reduced SIR (80, 95% CI 71 to 90) for all cancers, and for neoplasm of rectum, rectosigmoid junction, and anus (SIR=45), female breast (SIR=30) and cervix uteri (SIR=10). On the other hand, we noted that physicians of TCM suffered from a significantly increased SIR for neoplasm of liver and intrahepatic bile ducts (SIR=151, 95% CI 116 to 192) and of bladder cancer (SIR=259, 95% CI 167 to 382).
Conclusion Like other healthcare workers, we noted that physicians of TCM had significantly reduced risks of all-causes mortality and cancer incidence. Nonetheless, reasons truly responsible for significantly increased risks of liver and bladder neoplasm among physicians of TCM warrant further investigations.
- herbal medicine
- liver neoplasms
- mortality studies
- traditional Chinese medicine
- urinary bladder neoplasms
C-YL and T-NW contributed equally to this study.
Funding This study was supported by a grant from National Scientific Council, Taiwan (NSC 95-2314-B-030-002).
Competing interests None.
Ethics approval Ethics approval was provided by the Taiwan Chinese Medical Association and the Department of Health, Taiwan.
Provenance and peer review Not commissioned; externally peer reviewed.