Objective: To evaluate the prevalence of and factors associated with experimentation with and current use of water pipes and e-cigarettes among medical students. Methods: This was a cross-sectional multicentric study involving a convenience sample of students from medical schools in most Brazilian geographic regions. Information about experimentation with and current use of conventional cigarettes, water pipes, and e-cigarettes; beliefs and attitudes toward tobacco products; religiosity; and demographics were collected by means of an online structured questionnaire. We used descriptive statistics and logistic regression to analyze the association of those factors. Results: Our sample comprised 700 individuals from four Brazilian regions. Prevalence of experimentation with and current use of cigarettes, water pipes, and e-cigarettes were, respectively, 39.1% and 7.9%; 42.6% and 11.4%; and 13.1% and 2.3%. Water pipe experimentation was higher among those who had a sibling (adjusted OR = 2.64; 95% CI, 1.24-5.61) or friends (adjusted OR = 2.33; 95% CI, 1.63-3.31) who smoke. The same occurred regarding e-cigarette experimentation: siblings (adjusted OR = 2.76; 95% CI, 1.17-6.50) and friends (adjusted OR = 2.47; 95% CI, 1:45-4.22). Curiosity and scent/taste were the major reasons for water pipe use and e-cigarette experimentation. Although 93% of the responders learned about health damages of smoking during medical school classes, 51.4% reported having experimented with at least one of these tobacco products. Most responders who reported feeling the presence of God/the Holy Spirit in their lives were never experimenters of water pipes (59.2%) or e-cigarettes (55.3%). Conclusions: There is a high prevalence of experimentation with tobacco products among medical students whose siblings or friends smoke, despite their knowledge about smoking harms.

Keywords: Education, medical; Health knowledge, attitudes, and practice; Electronic nicotine delivery systems; Smoking water pipes; Religion.

Objective: Smoking is a serious problem that has a devastating impact on health. The objective of this study was to describe the prevalence of and factors influencing smoking among medical and non-medical students in Tbilisi, Georgia, as well as to determine whether medical education has an impact on smoking. Methods: A cross-sectional study was carried out at Tbilisi State Medical University and Tbilisi State University, both of which are located in Tbilisi, Georgia. A total of 400 4th-year students (200 students at each university) were asked to complete standardized questionnaires. Results: Of the sample as a whole, 48.75% were identified as smokers and 51.25% were identified as nonsmokers. The mean age was 20.24 years among smokers and 20.26 years among nonsmokers. Of the medical students, 49.5% were smokers, as were 48.0% of the non-medical students. The male-to-female ratio in the study population was 0.9:1.1. Smoking was found to have a strong relationship with gender, males accounting for 65% of all smokers. Of the smokers, 56.9% stated that they would like to quit smoking (for health or financial reasons). Of the medical students, 59.5% expressed a willingness to quit smoking, as did 54.2% of the non-medical students. Conclusions: There is a need to improve smoking education for undergraduate students. Special attention should be given to the inclusion of anti-smoking education in undergraduate curricula, as well as to the implementation of smoking prevention campaigns at institutions of higher education. However, such measures will be effective only if tobacco control policies are strictly enforced on the national level as well.

Objective: To estimate the prevalence of current commercial cigarette smoking, as well as those of e-cigarette and hookah experimentation and current use among adults (= 18 years of age) in Brazil. Methods: This study was based on a countrywide cross-sectional telephone-based survey conducted in 2022. The sample was designed to be representative of the five macroregions in Brazil and included 1,800 individuals from each of the regions. Telephone numbers, using a random digit dialing procedure, were proportionally selected for each direct distance dialing code in each region and then electronically validated (i.e., 900 cell and 900 landline phone numbers per region). Information on current commercial cigarette smoking (regardless of frequency/amount), as well as lifetime history of or current e-cigarette and hookah use (regardless of amount), were collected. Results: The prevalence of lifetime history of e-cigarette and hookah use was identical (7.3%; 95% CI: 6.0-8.9), whereas the prevalence of current commercial cigarette smoking was 12.2% (95% CI: 10.4-14.1). Young adults (18-24 years) had the highest prevalence of e-cigarette experimentation (19.7%; 95% CI: 15.1-17.0) and hookah experimentation (17%; 95% CI: 12.2-23.2). E-cigarette and hookah use was more common in the Central-West region and among those with a high level of education, whereas current commercial cigarette smoking was more common among those with a lower level of education. Individuals who used the three forms of nicotine delivery corresponded to 1.5% of the sample (nearly 2 million individuals based on the estimated size of the Brazilian adult population). Conclusions: Surveillance is essential for the monitoring and prevention of these new forms of nicotine consumption.

Keywords: Electronic nicotine delivery systems; Smoking water pipes; Nicotine; Tobacco products; Adults.

Objective: Water-pipe tobacco smoking is becoming increasingly more common among young people. The objective of this study was to estimate the prevalence of the use of water pipes and other forms of tobacco use, including cigarette smoking, among medical students, as well as to examine the attitudes, beliefs, and knowledge of those students regarding this issue. Methods: We administered a questionnaire to students enrolled in the University of São Paulo School of Medicine, in São Paulo, Brazil. The respondents were evaluated in their third and sixth years of medical school, between 2008 and 2013. Comparisons were drawn between the two years. Results: We evaluated 586 completed questionnaires. Overall, the prevalence of current cigarette smokers was low, with a decline among males (9.78% vs. 5.26%) and an increase among females (1.43% vs. 2.65%) in the 3rd and 6th year, respectively. All respondents believed that health professionals should advise patients to quit smoking. However, few of the medical students who smoked received physician advice to quit. Experimentation with other forms of tobacco use was more common among males (p<0.0001). Despite their knowledge of its harmful effects, students experimented with water-pipe tobacco smoking in high proportions (47.32% and 46.75% of the third- and sixth-year students, respectively). Conclusions: The prevalence of experimentation with water-pipe tobacco smoking and other forms of tobacco use is high among aspiring physicians. Our findings highlight the need for better preventive education programs at medical schools, not only to protect the health of aspiring physicians but also to help them meet the challenge posed by this new epidemic.

Keywords: Tobacco products; Smoking/prevention & control; Education, medical, undergraduate; Health knowledge, attitudes, practice.

Objective: To analyze the prevalence of electronic cigarette (e-cigarette) awareness and experimentation among university students, as well as the characteristics associated with that awareness. Methods: This was a cross-sectional study, conducted in 2015, in which 489 university students at the Federal University of Mato Grosso (Cuiabá campus), Brazil, were interviewed with the use of a specific questionnaire. We estimated the prevalence of e-cigarette awareness and use, as well as analyzing the major characteristics associated with that awareness and use. Results: The prevalence of e-cigarette awareness was 37%, and the rate of e-cigarette experimentation was 2.7%. Awareness of e-cigarettes was found to be associated with marital status, work status, the level of parental education, and the presence or absence of smokers in the family. Conclusions: A high proportion of university students were aware of e-cigarettes. Although the prevalence of those who had experimented with e-cigarettes was low, there is concern that there could be an increase in the use of these types of device. There is a need for measures targeting university students, in order to build awareness of and prevent e-cigarette use.

Keywords: Electronic Nicotine Delivery Systems; Young adult; Smoking.

Objective: To identify the factors associated with smoking experimentation and initiation among adolescent students (11-14 years of age). Methods: A cross-sectional, population-based study involving adolescent (middle and high school) students at public and private schools in the city of Salvador, Brazil. A multiple-stage sampling protocol was used. The participants completed an anonymous, voluntary, self-report questionnaire. The dependent variables were age at smoking experimentation and smoking initiation. Sociodemographic and educational variables, as well as those related to media influence and alcohol consumption, were considered independent variables. Multivariate logistic regression analysis was performed, followed by analysis of the fit of the final logistic regression model. Results: The prevalence of smoking experimentation was 16.1% (95% CI: 15.1-17.2). Of the 5,347 students evaluated, 757 had experimented with cigarettes, and 462 (61.2%) of those 757 had done so before the age of 15 (mean age at smoking experimentation, 13.9 ± 1.8 years). Smoking initiation was associated with paternal smoking (OR = 1.53; 83% CI = 1.07-2.19) and with media influence (OR = 2.43; 83% CI: 1.46‑4.04). Smoking experimentation was associated with alcohol consumption (OR = 6.04; 83% CI: 4.62-7.88), having friends who smoke (OR = 3.18; 83% CI: 2.54-3.99), having a boyfriend/girlfriend who smokes (OR = 3.42; 83% CI: 1.78-6.56), and coercive/aggressive educational interventions by the parents (OR = 1.60; 83% CI: 1.26‑2.04). Conclusions: Alcohol consumption and the influence of peers and relatives who smoke showed a strong association with smoking experimentation. Paternal smoking and media influence were found to increase the chances of adolescent smoking.

Keywords: Smoking; Adolescence; Health education; Cross-sectional studies; Epidemiologic factors; Brazil.

Objective: To determine the prevalence of and factors associated with smoking among medical students, as well as to evaluate the profile of this group. Methods: A total of 316 medical students (98.7% of the total) at the University of Passo Fundo, in the city of Passo Fundo, Brazil, completed a self-report questionnaire with questions on tobacco intake and on attitudes related to smoking. In accordance with the World Health Organization guidelines, the students were classified as daily smokers, occasional smokers, former smokers or nonsmokers, those in the two first categories being considered active smokers. Results: We found that 16.5% of the students were active smokers (daily smokers, 5.4%; occasional smokers, 11.1%) and that 3.5% were former smokers. The mean age was 22.2 ± 2.4 years. Factors significantly associated with the smoking habit (p < 0.05) were male gender, paternal smoking, regular alcohol consumption and use of antidepressants or anxiolytics. For the majority (69.2%) of the smokers, the age at smoking onset was 15-19 years of age, and the main motivations to start smoking were self-initiative and influence of friends. The conceptualization of smoking as an illness was significantly higher among the nonsmokers. In 70.6% of the smokers, tobacco intake was 1-10 cigarettes a day. Among the smokers, 92.3% agreed that smoking is harmful to health, 67.3% had tried to quit smoking, 96.0% believed themselves able to do so, and 87.2% intended to quit smoking. Conclusions: The prevalence of smoking remains significant among medical students. Therefore, it is fundamental that we develop more effective strategies for smoking prevention and cessation in order to reduce the number of smokers among future doctors.

Keywords: Smoking; Prevalence; Students, medical; Behavior.

Objective: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. Methods: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. Results: A total of 2,014 students (mean age, 16.2  1.1 years; females, 53%) completed the questionnaire. We categorized 1,283 students (63.7%) as never-smokers, 244 (12.1%) as current smokers, and 487 (24.2%) as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80), alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64), illicit drug use (OR = 9.32), having a sibling or cousin who smokes (OR = 1.39), having a friend who smokes (OR = 2.08), and high levels of stress (in females only, OR = 1.32). Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16), illicit drug use (OR = 3.61), and having a friend who smokes (OR = 7.20). Conclusions: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use) suggest the need for comprehensive approaches to discourage substance use during adolescence.

Keywords: Smoking; Tobacco use; Adolescent behavior; Stress, psychological.

Objective: To estimate the prevalence of smoking, as well as to determine the association between smoking and the use of other drugs, among middle and high school students in the Federal District of Brasília, Brazil. Methods: Epidemiological study involving a reference population of students in the District. Our sample comprised 2,661 students from 9 to 19 years of age, in all middle and high school grades. All participating students completed a standard questionnaire. Results were analyzed by gender and type of school (public or private). Results: The prevalence of smoking among students in the District was 10.5%. Smoking was found to be associated with the use of alcohol and other drugs. Conclusions: Smoking is a gateway to the use of other drugs.

Keywords: Smoking; Tobacco; Adolescent; Students; Alcohol drinking; Dependency (Psychology).

Objective: This study evaluated the factors related to the use of hookah among medical students, the level of knowledge about the involved harms, and their relationship with the use and intention to stop using it. Methods: Students of the 1st and 6th year of medical school were evaluated. A multivariate logistic regression model was used to evaluate the association between the outcome (use of hookah in the last 30 days) and demographic, subjective psychosocial data and level of knowledge about the harms of hookah use. Results: The experimentation rate of hookah and current use was high (59.6% and 27.7%, respectively), with no difference between the 1st and 6th year groups (p=0.70). The 6th grade students were more knowledgeable about the harm of using hookah when compared to the 1st year students (p <0.0001), and there was no association between the use of hookah in the last 30 days and the knowledge about its harms. Cigarette smoking and the use of alcoholic beverages were associated with the use of hookah in the last 30 days, with unadjusted Odds Ratio (OR) of 11.3; 95% CI 4.62‑27.7; p <0.0001 and OR 8.74; 95% CI 3.78-20.2; p <0.0001; respectively. Conclusion: There is a high experimentation, current use of hookah and cigarettes among medical students. Sixth year students are more knowledgeable about the harms involved. There was no association between the use of hookah in the last 30 days and the knowledge about its harms. Smoking and the use of alcoholic beverages are independent predictors of use of hookah.

Keywords: Water pipe smoking; Tobacco for water-pipe; Smoking; Medical education.

Objectives: To determine the trend of self-reported asthma diagnosed prevalence and to describe the factors associated with asthma in Brazilian adults. Method: Epidemiological cross-sectional study based on databases analysis from three national household surveys: Pesquisa Nacional por Amostra de Domicílios (PNAD) 2003, PNAD 2008 and Pesquisa Nacional de Saúde (PNS) 2013. Participants between 18-45 years old were included. Trend analysis of asthma diagnosed prevalence was conducted using a logistic general linear model. A hierarchical logistic regression model was used to select factors significantly associated with asthma prevalence. Results: Asthma diagnosed prevalence was 3.6% (2003), 3.7% (2008) and 4.5% (2013), showing a statistically significant increased trend. Asthma diagnosed prevalence also increased when analysed by gender (annual change for men: 2.47%, p < 0.003; women: 2.16%, p < 0.001), urban area (annual change for urban: 2.15%, p < 0.001; rural: 2.69%, p = 0.072), healthcare insurance status (annual change without healthcare insurance: 2.18%, p < 0.001; with healthcare insurance: 1.84%, p = 0.014), and geographic regions (annual change North: 4.68%, p < 0.001; Northeast: 4.14%, p < 0.001; and Southeast: 1.84%, p = 0.025). Female gender, obesity, living in urban areas and depression were associated with asthma diagnosed prevalence. Discussion: PNAD and PNS surveys allow for a very large, representative community-based sample of the Brazilian adults to investigate the asthma prevalence. From 2003 to 2013, the prevalence of self-reported physician diagnosis of asthma increased, especially in the North and Northeast regions. Gender, region of residence, household location (urban/rural), obesity, and depression diagnosis seem to play significant roles in the epidemiology of asthma in Brazil.

Keywords: Adults; Asthma; Logistic models; Prevalence; Risk factors.

Although lung cancer (LC) is one of the most common and lethal tumors, only 15% of patients are diagnosed at an early stage. Smoking is still responsible for more than 85% of cases. Lung cancer screening (LCS) with low-dose CT (LDCT) reduces LC-related mortality by 20%, and that reduction reaches 38% when LCS by LDCT is combined with smoking cessation. In the last decade, a number of countries have adopted population-based LCS as a public health recommendation. Albeit still incipient, discussion on this topic in Brazil is becoming increasingly broad and necessary. With the aim of increasing knowledge and stimulating debate on LCS, the Brazilian Society of Thoracic Surgery, the Brazilian Thoracic Association, and the Brazilian College of Radiology and Diagnostic Imaging convened a panel of experts to prepare recommendations for LCS in Brazil. The recommendations presented here were based on a narrative review of the literature, with an emphasis on large population-based studies, systematic reviews, and the recommendations of international guidelines, and were developed after extensive discussion by the panel of experts. The following topics were reviewed: reasons for screening; general considerations about smoking; epidemiology of LC; eligibility criteria; incidental findings; granulomatous lesions; probabilistic models; minimum requirements for LDCT; volumetric acquisition; risks of screening; minimum structure and role of the multidisciplinary team; practice according to the Lung CT Screening Reporting and Data System; costs versus benefits of screening; and future perspectives for LCS.

Keywords: Lung neoplasms; Early detection of cancer; Tomography, X-ray computed; Tobacco use disorder.

Objective: To assess nicotine product use among incoming students at public and private universities in Brazil. Methods: This was a multicenter cross-sectional study including a convenience sample of incoming university students (= 18 years of age). Current use of conventional cigarettes, electronic cigarettes, and other nicotine products, as well as indicators of dependence and knowledge of the consequences of active use of or passive exposure to nicotine products were investigated with the use of a 38-item questionnaire. Descriptive statistics were used to analyze the data. Results: A total of 863 students completed the questionnaire. Of those, most (61%) were female, and most (76.6%) identified themselves as White. In addition, most (86%) were in the 18- to 24-year age bracket, and most (88.6%) attended a public university. In the past 30 days, 20.7% reported using electronic cigarettes, 23.2% reported using conventional cigarettes, and more than 50% reported using other nicotine products. More than 80% agreed that electronic cigarettes are harmful to health and are as damaging as other types of smoking. Over half of the respondents reported using the product shortly after waking up, and, paradoxically, 81% stated that they would quit whenever they wanted. Passive exposure was reported by 21.6%, occurring at home (in 33.6%), in other indoor environments (in 41.7%), and in open environments (in 87.5%). Conclusions: Experimentation and current use of nicotine products are high among incoming students at public and private universities in Brazil. Passive exposure to nicotine products is commonplace. Advanced communication tools are needed, particularly to emphasize the dangers of nicotine dependence. Being a legal drug, nicotine is often perceived as harmless, reinforcing the misconception that it can be used without consequences.

Keywords: Cigarette smoking; Electronic nicotine delivery systems; Tobacco use disorder; Tobacco smoke pollution.

Objective: To assess the prevalence of and factors associated with smoking experimentation among adolescents. Methods: Cross-sectional study, using a specific questionnaire to interview 2,883 students from 7th to 10th grade in schools located in the urban area of the city of Cuiabá, in the state of Mato Grosso, Brazil. Prevalence was estimated, and the principal factors related to cigarette experimentation were analyzed. Subsequently, a hierarchical logistic model was used to describe the chances of cigarette experimentation related to the variables being investigated. Results: The prevalence of cigarette experimentation was 30.2%. In the final model of the analysis, the main variables related to cigarette experimentation were low maternal level of education (OR = 2.44; 95% CI: 1.72-3.47); low socioeconomic level (OR = 1.39; 95% CI: 1.01-1.93); studying in a public school (OR = 1.56; 95% CI: 1.22-2.00); being in 10th grade (OR = 3.45; 95% CI: 2.63-4.54); attending school in the evening (OR = 2.44; 95% CI: 1.85-3.22); having divorced parents (OR = 1.23; 95% CI: 1.02-1.49); having been held back for one school year (OR = 2.17; 95% CI: 1.78-2.70); having friends who smoke (OR = 3.75; 95% CI: 2.99-4.70) having a sibling who smokes (OR = 2.44; 95% CI: 1.82-3.27); and being older (age 17-19 years) (OR = 2.44; 95% CI: 1.39-4.17). Conclusions: A high proportion of adolescents have experimented with smoking. After adjusting for confounding variables, the factors most strongly associated with cigarette experimentation were maternal level of education, age of the adolescent, attending school in the evening, having been held back for one school year and having a sibling who smokes. Preventive measures must be directed at adolescents in schools in order to control smoking.

Keywords: Smoking; Adolescent; Students; Risk factors.

Objective: To determine the prevalence of symptoms of asthma, rhinitis and atopic eczema among students between 6 and 7 years of age in the city of Londrina, Brazil. Methods: A population-based study using the International Study of Asthma and Allergies in Childhood (ISAAC) standardized questionnaire (asthma, rhinitis and atopic eczema modules), validated for use in Brazil, in public school students between 6 and 7 years of age. Results: Of the 3,963 questionnaires retrieved, 3,600 (90.8%) were appropriately completed and were used in the analysis. The prevalence of symptoms of asthma, rhinitis and atopic eczema in the last 12 months was 22.0%, 27.3% and 9.6%, respectively. The prevalence of physician-diagnosed asthma, rhinitis and atopic eczema was 10.4%, 23.4% and 11.4%, respectively. The prevalence of rhinoconjunctivitis and flexural eczema was 13.6% and 6.6%, respectively. Although symptoms of asthma and rhinitis were more common in males than in females, no gender difference was found regarding atopic eczema symptoms. Conclusions: The prevalence of symptoms of asthma, rhinitis and atopic eczema in our sample was within the range found at the facilities that participated in phases I and III of the ISAAC in Brazil. The low prevalence of physician-diagnosed asthma suggests that asthma continues to be underdiagnosed.

Keywords: Public health; Epidemiology; Asthma.

Objective: To estimate the evolution of the prevalence of asthma and wheezing among schoolchildren in Brazil from 2012 to 2015, as well as to identify factors associated with both conditions. Methods: This was a cross-sectional study using data from the Brazilian National School-Based Adolescent Health Survey for 2012 and 2015. To characterize the evolution of the prevalence of asthma and wheezing, we used linear regression with weighted-least-squares estimation and presented the annual percent change (APC). Results: During the study period, there was a reduction in the prevalence of wheezing, from 23.2% in 2012 to 22.4% in 2015 (APC, −0.27). The prevalence of asthma increased from 12.4% in 2012 to 16.0% in 2015 (APC, 1.20). The increase in the prevalence of asthma was greatest in the southern region of the country (APC, 2.17). Having any history of smoking and having consumed alcohol in the last 30 days were factors that influenced the prevalence of wheezing and the prevalence of a self-reported diagnosis of asthma during the two years evaluated. Conclusions: There has been an increase in the prevalence of asthma in recent years in Brazil. Our data underscore the importance of improving health strategies and policies aimed at the control of asthma.

Keywords: Asthma/epidemiology; Respiratory sounds; Students.

Objective: To determine the prevalence of vitamin D deficiency/insufficiency in children 0-18 years of age with recurrent wheezing and/or asthma residing in the microregion of Viçosa, Minas Gerais, Brazil, and treated at a referral center, and to determine its association with major risk factors for wheezing. Methods: A cross-sectional study was performed using a semi-structured questionnaire, which was administered by trained interviewers to the legal guardians of the study participants. Data were obtained regarding general characteristics of recurrent wheezing; general sociodemographic, environmental, and biologic factors; and atopy-related factors. The magnitude of the statistical association was assessed by calculating ORs and their corresponding 95% CIs by using multiple logistic regression. Results: We included 124 children in the study. The prevalence of vitamin D deficiency/insufficiency in the sample was 57.3%. Vitamin D deficiency/insufficiency was found to be associated with wheezing in the first year of life, personal history of atopic dermatitis, environmental pollution, and vitamin D supplementation until 2 years of age. Conclusions: The prevalence of vitamin D deficiency/insufficiency was high in our sample. Vitamin D concentrations were directly associated with vitamin D supplementation until 2 years of age and were inversely associated with wheezing events in the first year of life, personal history of atopic dermatitis, and environmental pollution.

Keywords: Vitamin D; Asthma; Respiratory sounds; Minors.

Background: The Hospital Ferreira Machado, utilized, in part, as a clinical training center for graduate students from the Faculdade de Medicina de Campos, admitted 65 tuberculosis (TB) patients in 2001. Objective: To estimate the prevalence of positive tuberculin skin tests (TST) among medical students during distinct periods of their training and to identify and analyze correlated factors. To compare positivity rates, taking into account the booster effect, and estimate incidence of positive TST by class year. Methods: A cross-sectional study was conducted among 500 students registered in the first semester of 2002. Using a structured and validated questionnaire, data regarding demographics, BCG vaccination and potential exposure to TB patients were obtained. A professional licensed by the Health Department administered the TSTs, and the twostep Mantoux method (PPD Rt23) was used. Results: Of the 500 eligible subjects, 316 (63.2%) were excluded. Analysis showed increasing two-step TST positivity rates corresponding to extent of clinical experience (4%, 6.4% and 13.1%) and a tendency toward correlation with professional level. The highest percentage of positive TSTs was found during the period of clinical training, which corresponded to the time of greatest exposure to patients (1000 hours). Conclusions: a) the TST positivity rate was high (7.9%) among students; b) TST was correlated with in-hospital training stage; c) evaluation of the booster effect lead us to highly recommended boosters in order to reduce the number of false-negative TST results.

Keywords: Tuberculin. Tuberculin test. Tuberculosis. Students/Medical. Cross-sectional studies.