Mortality and cancer incidence among physicians of traditional Chinese medicine: a 20-year national follow-up study.
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).


CONCLUSIONS
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.
Liu
Shu-Hui
SH
Institute of Environmental Health, College of Public Health, China Medical University and Hospital, 91 Hseuh-Shih Road, Taichung 404, Taiwan.
Liu
Yu-Feng
YF
Liou
Saou-Hsing
SH
Lin
Yun-Lian
YL
Hsiao
Yuen-Chen
YC
Chen
Chu-Chieh
CC
Li
Chung-Yi
CY
Wu
Trong-Neng
TN
D000328:Adult; D002423:Cause of Death; D015331:Cohort Studies; D004365:Drugs, Chinese Herbal / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008113:Liver Neoplasms / Q000401:mortality; D008297:Male; D008516:Medicine, Chinese Traditional; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality*; D009784:Occupational Diseases / Q000401:mortality*; D016273:Occupational Exposure; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000401:mortality; D055815:Young Adult
D004365:Drugs, Chinese Herbal