COVID-19 incidence, severity, medication use, and vaccination among dentists: survey during the second wave in Brazil

Abstract Objective This cross-sectional study with dentists in Brazil assessed the COVID-19 incidence and severity, its vaccination status, and the level of confidence in vaccines in May 2021 (COVID-19 second wave). The medications used to prevent or treat COVID-19, including controversial substances (vitamin D, ivermectin, zinc, and chloroquine), were analyzed. Methodology Dentists were recruited by email and responded to a pretested questionnaire until May 31, 2021. Bivariate and multivariate regression analyses were performed (α=0.05). Prevalence ratios were calculated for the association between professional characteristics and two outcomes: SARS-CoV-2 infection and use of controversial substances. Results In total, 1,907 responses were received (return rate of 21.2%). One third of dentists reported intermediate levels of confidence in the safety and efficacy of COVID-19 vaccines, but 96% had received at least one vaccine dose, mainly CoronaVac. The effect of the pandemic on dental practice was classified as lower/much lower, in comparison with the first wave, by 46% of participants. Moreover, 27% of dentists had already tested positive for SARS-CoV-2 and about 50% had relatives or friends who had been hospitalized or died from COVID-19. At least one medication was used by 59% of participants and 43% used two or more substances. Vitamin D (41%), ivermectin (35%), and zinc (29%) were the most frequent substances. More experienced dentists (≥21 years of professional experience) were 42% more likely to use controversial substances than less experienced dentists. The prevalence of use of controversial substances was 30% higher among dentists with residency or advanced training, such as postgraduate degrees, in comparison with participants holding MSc or PhD degrees. Participants with low confidence in vaccines were 2.1 times more likely to use controversial substances than participants with a very high confidence. Conclusion The results of this study show the high severity of the COVID-19 pandemic in Brazil and raised questions about the use of scientific evidence by dentists in their decision to use controversial substances.

摘要 目的 本项针对巴西牙科医师的横断面研究，于2021年5月（新冠第二波疫情期间）评估了新冠感染的发生率与严重程度、受试者的疫苗接种情况，以及对新冠疫苗的信心水平。本研究同时分析了用于预防或治疗新冠的各类药物，包括维生素D、伊维菌素、锌剂及氯喹等有争议的药物。

方法 本研究通过电子邮件招募牙科医师，截至2021年5月31日回收经过预试验验证的问卷。采用双变量及多变量回归分析（检验水准α=0.05），计算患病率比以分析职业特征与两个结局指标——严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染、使用有争议药物——之间的关联。

结果 本研究共回收有效问卷1907份，回收率为21.2%。三分之一的牙科医师表示对新冠疫苗的安全性与有效性持中等信心水平，但96%的受试者已接种至少一剂新冠疫苗，其中以科兴灭活疫苗（CoronaVac）为主。46%的参与者认为，与新冠第一波疫情相比，本次疫情对牙科临床工作的影响程度更低或显著更低。此外，27%的牙科医师新冠病毒检测结果呈阳性，约50%的受试者有亲属或朋友因感染新冠住院或死亡。59%的参与者至少使用过一种预防或治疗新冠的药物，43%的受试者使用了两种及以上此类药物。最常用的三种药物依次为维生素D（41%）、伊维菌素（35%）及锌剂（29%）。从业年限≥21年的高年资牙科医师使用有争议药物的概率较低年资医师高42%。与持有理学硕士（MSc）或哲学博士（PhD）学位的受试者相比，拥有住院医师规范化培训或高级进修经历（如研究生学位）的医师使用有争议药物的患病率高30%。对疫苗信心较低的受试者使用有争议药物的概率是信心极高者的2.1倍。

结论 本研究结果凸显了巴西新冠疫情的严峻态势，并对牙科医师在临床决策中选用有争议药物时是否遵循科学证据提出了质疑。