Long-term exposure to ambient fine particulate matter and periodontitis: An observational study using nationally representative survey data.

AIM: The rising prevalence of periodontitis imposes substantial burdens on individuals and society. Identifying environmental risk factors for periodontitis may contribute to tackling the global public health burden of it. This study aimed to assess the association between long-term exposure to PM2.5 and periodontitis in a nationally representative population from China. MATERIALS AND METHODS: In this multi-centre cross-sectional study of 372 communities in 31 provinces of Mainland China, we used data from the Fourth National Oral Health Survey of China in 2015-2016, in combination with high-resolution gridded concentrations of fine particulate matter (PM2.5). Logistic regression was applied to assess the relationship between long-term PM2.5 exposure and the risk of periodontitis. In addition, we examined whether the association varied by individual characteristics, and estimated the exposure-response relationship and the risk of damaged tooth in each tooth quadrant. RESULTS: A total of 8391 participants from 96 cities were diagnosed with periodontitis, accounting for 60.04% (8391/13,459) of the participants. For each 10 µg/m3 increment in 1-, 3- and 5-year average concentrations of PM2.5, the risk of total periodontitis increased by 9.0% (95% confidence interval: 6.0%, 12.0%), 8.0% (6.0, 11·0) and 7.0% (5.0, 10.0), respectively. Mild periodontitis was more strongly associated with PM2.5 exposure than moderate and severe periodontitis. The teeth in the lower anterior, lower posterior or upper anterior are more susceptible to the effect of PM2.5 on the periodontal pocket, calculus and bleeding gums. CONCLUSIONS: Long-term exposure to PM2.5 is significantly associated with an increased risk of periodontitis in the nationally representative Chinese population. Considering the rising prevalence of periodontitis, considerable costs of treatment, and substantially adverse effects on individuals and society, these findings suggest that stricter air quality regulations may help ease the burden of periodontal disease.

Cost-effectiveness analysis of fruquintinib for metastatic colorectal cancer third-line treatment in China.

BACKGROUND: In this study, we analyze the cost-effectiveness of fruquintinib as third-line treatment for patients with metastatic colorectal cancer in China, especially after a recent price drop suggested by the National Healthcare Security Administration. METHODS: A Markov model was developed to investigate the cost-effectiveness of fruquintinib compared to placebo among patients with metastatic colorectal cancer. Effectiveness was measured in quality-adjusted life years (QALY). The Chinese healthcare payer's perspective was considered with a lifetime horizon, including direct medical cost (2019 US dollars [USD]). A willing-to-pay threshold was set at USD 27,130/QALY, which is three times the gross domestic product (GDP) per capita. We examined the robustness of the model in one-way and probabilistic sensitivity analysis. RESULTS: Fruquintinib was associated with better health outcomes than placebo (0.640 vs 0.478 QALYs) with a higher cost (USD 20750.9 vs USD 12042.2), resulting in an incremental cost-effectiveness ratio (ICER) of USD 53508.7 per QALY. This ICER is 25% lower than the one calculated before the price drop (USD 70952.6 per QALY). CONCLUSION: After the price negotiation, the drug becomes cheaper and the ICER is lower, but the drug is still not cost effective under the standard of 3 times GDP willing-to-pay threshold. For patients with metastatic colorectal cancer in China, fruquintinib is not a cost-effective option under the current circumstances in China.