Background: Subjects with head and neck cancer (HNC) often experience post-treatment side effects, particularly radiation-induced oral mucositis (RIOM). This study aimed to explore the association of Chinese herbal medicine use with the sequent risk of RIOM among them. Methods: This cohort study used a nationwide health insurance database to identify subjects newly diagnosed with HNC, aged 20 to 60 years, who received treatment between 2000 and 2007. Among them, a total of 561 cases received CHM after HNC onset (CHM users); the remaining 2395 cases were non-CHM users. All patients were followed to the end of 2012 to identify any treatment for RIOM as the end point. Cox proportional hazards regression was used to compute the adjusted hazard ratio (aHR) of RIOM by CHM use. Results: During the follow-up period, 183 CHM users and 989 non-CHM users developed RIOM at incidence rates of 40.98 and 57.91 per 1000 person-years, respectively. CHM users had a lower RIOM risk than the non-CHM users (aHR: 0.68; 95% Confidence Interval: 0.58-0.80). The most potent effect was observed in those taking CHM for more than 1 year. Use of Baizhi, Danshen, Shao-Yao-Gan-Cao-Tang, Gan-Lu-Yin, Huangqin, Shu-Jing-Huo-Xue-Tang, and Xin-Yi-Qing-Fei-Tang, was significantly related to a lower risk of RIOM. Conclusion: Findings of this study indicated that adding CHM to conventional clinical care could be helpful in protecting those with HNC against the onset of RIOM. Further clinical and mechanistic studies are warranted.

Objectives: Patients with rheumatoid arthritis (RA) are at a higher risk of extra-articular manifestations, especially hearing loss (HL). Although Chinese herbal medicines (CHM) are proven safe and effective treatments for inflammatory conditions, the effect of CHM use on HL in RA patients is unknown. This cohort study aims to determine the relationship between CHM use and the subsequent risk of HL among RA patients.Methods: From health insurance claims data in Taiwan, a total of 6,905 persons aged 20–80 years with newly-diagnosed RA in 2000–2009 were identified. Of these, we recruited 2,765 CHM users and randomly selected 2,765 non-CHM users who matched with the users by the propensity score. Both cohorts were followed up until the end of 2012 to estimate the incidence of HL. Cox proportional hazards regression was used to estimate the adjusted hazard ratio (HR) for HL.Results: The incidence of HL was lower in the CHM users than in the comparison cohort (8.06 vs. 10.54 per 1,000 person-years) (adjusted HR, 0.77; 95% CI, 0.63–0.94). Those who received CHM for more than 2 years had the greatest benefit against the onset of HL, with over 50% risk reduction. Prescriptions of Hai Piao Xiao, Yan Hu Suo, San-Qi, Huang Qin, Dang Shen, Jia-Wei-Xiao-Yao-San, Shu-Jing-Huo-Xue-Tang, and Dang-Gui-Nian-Tong-Tang were found to be associated with a reduced risk of HL.Conclusions: Our findings suggest that adding CHM to conventional therapy may reduce the subsequent risk of HL in RA patients. Prospective randomized trials are recommended to further clarify whether the association revealed in this study supports such a causal relationship.