|Year : 2015 | Volume
| Issue : 1 | Page : 1-7
Smoking habits, awareness of risks, and attitude towards tobacco control policies among medical students in Lagos, Nigeria
Michelle G Dania, Obianuju B Ozoh, Emmanuel O Bandele
Department of Medicine, College of Medicine, University of Lagos, Lagos, Nigeria
|Date of Web Publication||7-Jan-2015|
Obianuju B Ozoh
Department of Medicine, College of Medicine, University of Lagos, Lagos
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: This study aimed to assess the prevalence of cigarette smoking among medical students, and to determine their level of knowledge regarding risk associated with cigarette smoking and their attitude and behavior towards tobacco control strategies and policies.
Materials and Methods: A stratified random sampling approach was used to select participants. A modified version of the the Global Health Professional Students Survey questionnaire was self-administered. Descriptive statistics were applied and comparisons were done using chi-square test. Multivariate logistic regression was used to obtain the significant determinants of smoking. A P < 0.05 was considered significant.
Results: A total of 250 students participated in the study with a response rate of 89.2%. The mean age (years) was 21.4 3. Rate of ever smoking and current smoking was 9.6 and 1.2%, respectively. Age > 21, having a smoking father, and use of alcohol were significantly associated with ever smoking. Knowledge of smoking as a risk for emphysema was 72.8%, coronary artery disease 82.8%, stroke 68.8%, and low birth weight 76.4%. There were 103 (41.2%) students aware of antidepressant usage in smoking cessation. One hundred and ninety-five (78%) offered smoking cessation advice if a smoker had no smoking-related disease and did not seek their opinion about smoking, 68.8% affirmed to having adequate knowledge on smoking cessation, and 56.8% had received formal training on smoking cessation techniques. The ban on cigarette smoking in enclosed public places was supported by 92.4%.
Conclusions: The prevalence of current cigarette smoking among medical students in Lagos is relatively low. Gaps exist in the level of knowledge of the students regarding risks of cigarette smoking, tobacco cessation strategies, and in their attitude and behavior towards offering tobacco cessation advice. There is need therefore to include formal training on tobacco control strategies at an early stage in the medical curriculum.
| Abstract in French|| |
Fond: Cette étude visait à évaluer la prévalence du tabagisme chez les étudiants en médecine et de déterminer leur niveau de connaissance au sujet du risque lié à l'usage de la cigarette et leur attitude et de comportement à l'égard des politiques et des stratégies de lutte antitabac.
Matériel et Méthodes: Approche d'échantillonnage aléatoire un stratifié a été utilisé pour sélectionner les participants. Une version modifiée de la questionnaire Global Health Professional étudiants sondage était autogéré. Statistiques descriptives ont été appliqués et comparaisons ont été effectuées à l'aide de test Khi-deux. Régression logistique multivariée a été utilisée pour obtenir les déterminants significatifs du tabagisme. Une P < 0,05 était considérée comme significative.
Résultats: Un total de 250 étudiants ont participé à l'étude avec un taux de réponse de 89,2%. L'âge moyen (années) était de 21,4 ± 3. Taux de jamais fumer et tabagisme actuel était de 9,6 et 1,2%, respectivement. Âge > 21, d'un père fumeur et la consommation d'alcool étaient significativement associés à jamais fumer. Connaissance du tabagisme comme un risque pour l'emphysème était 72,8% coronarienne maladie 82,8%, course 68,8% et faible à la naissance poids 76,4%. 103 Étudiants (41,2%) étaient au courant de l'utilisation des antidépresseur dans l'arrêt du tabac. Cent quatre-vingt - cinq (78%) offre des avis de cessation de fumer si un fumeur n'a aucune maladie liée au tabagisme et n'a pas demandé leur opinion sur le tabagisme, 68,8% confirmé pour avoir une connaissance adéquate sur le renoncement au tabagisme et 56,8% avaient reçu une formation sur les techniques de cessation de fumer. L'interdiction d'usage de la cigarette dans les lieux publics fermés a été pris en charge par 92,4%.
Conclusions: La prévalence du tabagisme actuel chez les étudiants en médecine à Lagos est relativement faible. Des lacunes existent dans le niveau de connaissances des élèves concernant les risques de la consommation de cigarettes, stratégies de cessation du tabac et dans leur attitude et leur comportement à offrir des conseils de cessation du tabac. Il y a donc nécessité d'inclure une formation officielle sur les stratégies de lutte antitabac à un stade précoce dans le programme d'études médical.
Mots-clés: Les étudiants en médecine, Nigeria, fumer
Keywords: Medical students, Nigeria, smoking
|How to cite this article:|
Dania MG, Ozoh OB, Bandele EO. Smoking habits, awareness of risks, and attitude towards tobacco control policies among medical students in Lagos, Nigeria. Ann Afr Med 2015;14:1-7
|How to cite this URL:|
Dania MG, Ozoh OB, Bandele EO. Smoking habits, awareness of risks, and attitude towards tobacco control policies among medical students in Lagos, Nigeria. Ann Afr Med [serial online] 2015 [cited 2020 Oct 20];14:1-7. Available from: https://www.annalsafrmed.org/text.asp?2015/14/1/1/148701
| Introduction|| |
There are approximately 1.3 billion regular smokers in the world and over 80% live in the developing countries.  In the African region, smoking prevalence has increased steadily over the years, at a rate that is 2.5% higher than in other developing regions.  In Nigeria for instance, the prevalence of smoking increased from 8.9% as reported in a national survey in 1990 to 16.8% in the 2002-2003 World Health Organization (WHO) World Mental Health Survey.  Higher rates of about 32% have been reported more recently in the north eastern region of the country. 
Health professionals, especially doctors, have an important role to play in tobacco control. Doctors are expected to serve as nonsmoking role models in the society; educate the public about the dangers of smoking; counsel and assist patients to quit smoking; and support governments in implementing anti-tobacco policies.  Nevertheless, quite a number of doctors still smoke and thus do not offer smoking cessations advice to patients. ,, Some doctors also lack the knowledge and skills required to offer smoking cessation intervention.  Medical students on their part are very important in tobacco control since their smoking habits, knowledge, and attitude to smoking will influence their future practice as doctors. Cigarette smoking is still widespread among medical students and prevalence varies from place to place often reflecting that of the society in which they live.  In Nigeria, prevalence rates of current cigarette smoking of 3% among medical students has been reported recently (2006), much lower than earlier reports that showed rates of 10-65% with the highest rate reported from College of Medicine of the University of Lagos in 1976. ,,,,
Despite the relatively lower rates of cigarette smoking reported among medical student in Nigeria recently, the rates of smoking in the general population is still high. This may be a reflection of the knowledge of doctors, medical students, and other healthcare professionals regarding the risk of cigarette smoking and tobacco control strategies as well as their attitude and behavior towards patients counseling on smoking cessation and tobacco control policies. Earlier studies among medical students in Nigeria have not extensively addressed the level of knowledge, attitude, and behavior of the students as regards risks of cigarette smoking and its control. We therefore designed this study to determine the current prevalence of cigarette smoking among medical students at the College of Medicine, University of Lagos, Nigeria. We also aimed to assess the level of knowledge, attitude, and behavior regarding smoking-related diseases and tobacco control strategies among the students.
| Materials and Methods|| |
This was a descriptive cross-sectional study of medical students at the College of Medicine, University of Lagos, Nigeria. Prior to commencement of the study, ethical approval was obtained from the Health Research Ethics Committee (HREC) of the Lagos University Teaching Hospital. Only second year to sixth year (final year) medical students were included (first year student are in their pre-med year).
There were a total of 760 medical students in second year to final year during the study period (2010-2011 academic session). An initial pilot study was carried out among dental students (who did not form part of the study population) to test the performance of the questionnaire and estimate the response rate. The results showed the questionnaire to be reliable; a focused group discussion following data collection showed that the questions were easily understood and did not require modifications. An initial sample size of 233 was calculated taking into account the population smoking prevalence rate of 16%  , we allowed a 5% error rate at 95% confidence interval (CI) and when back calculated, a power of 95% was achieved. Considering that the response rate obtained from the pilot study was 75%, the sample size was increased to 280 students to ensure that an adequate sample was obtained. A stratified random sampling approach was used based on five strata (second year to sixth year students respectively) to select the number of participants from each class level. The number of students to be recruited from each level was calculated based on the number of students in the level as a fraction of the total number of students in the college multiplied by the desired sample size.
The study instrument was a modified version of the the Global Health Professional Students Survey questionnaire and designed to obtain information on smoking habits, parents and friends' smoking status, knowledge of smoking-related diseases, and smoking cessation approaches as well as attitude towards tobacco control policies. After obtaining written informed consent, self-administered questionnaires with code numbers (to ensure confidentiality) were completed by the students who were randomly selected by balloting to obtain the desired sample size for each class. The questionnaires were distributed just before the start of a lecture and retrieved at the same sitting. The students were not allowed to consult each other while completing the questionnaires.
Data was analyzed using the Statistical Package for Social Sciences (SPSS) statistical package version 16. Two-way tables were used to test the independence of the variables and Chi-square tests were applied. Univariate and multivariate regressions were used to determine the factors significantly associated with cigarette smoking. A P < 0.05 was considered significant.
An ever-smoker was defined as a person who had smoked at least one cigarette in his or her life while a never-smoker was someone who had never smoked even a stick of cigarette in his or her entire life. Current smoking was considered as a person who reports having smoked a cigarette in the preceding 30 days to the study. The preclinical faculty included students in the second to third year of medical school while the clinical faculty included students from the fourth to the sixth year of medical school.
| Results|| |
A total of 280 students were recruited, however only 250 returned appropriately completed questionnaires, giving a response rate of 89.2%.
The age range of respondents was between 16 and 33 years. The mean age (years) was 21.4 ± 3. [Table 1] summarizes the age, gender, and class level as well as faculty distribution of the respondents. Participants were evenly distributed among the class levels. Two hundred and forty-eight (99.2%) were single and all the students had religious affiliations (Christianity or Islam) with 85.2% being Christians.
Prevalence of cigarette smoking and factors associated with smoking
Twenty four (9.6%) of the 250 participants were ever-smokers and 16 (67%) of them were males. The ever-smokers were distributed according to their year of study as follows; second year 3 (12.5%), third year 1 (4.2%), fourth year 3 (12.5%), fifth year 8 (33.3%), and final year 9 (37.5%). There were three current smokers (12.5% of ever-smokers and 1.2% of the total participants) of which two were males. Two of the current smokers were in their clinical years, and one was in the preclinical year. One smoked less than three sticks of cigarette daily, another three to five sticks of cigarette daily; while the third smoked between six to ten sticks of cigarette daily. The reasons for continuing smoking among the current smokers were for concentration and because their friends were smoking.
Twenty of the 24 ever-smokers responded concerning their age and course year of smoking initiation. The minimum age of smoking initiation was 8 years while the maximum age was 26 years (Median 18, interquartile range 14.5-20). Twelve (60%) began smoking before getting into the university, five (25%) began in their preclinical years, and three (15%) in their clinical years. Reasons for ever smoking was indicated by 21 participants; 16 (76.2%) were inquisitive, three (14.3%) smoked because their friends did, and two (9.5%) because a family member smoked.
We also enquired about the use of other psychoactive substances excluding cigarettes, it was found that 88 (35.2%) students used one or more other psychoactive substances. Caffeine-use was 49 (19.6%), followed by alcohol 34 (13.6%). Three (5%) students used sedatives and one person smoked cannabis. No student responded positively to the use of cocaine, amphetamines, or heroine.
To assess the factors that determined being an ever-smoker among the students, we used both univariate and multivariate analysis. In univariate analysis, age >21 years, having a smoking friend, and use of alcohol were significantly associated with ever smoking. For multivariate logistic regression, only factors with a P ≤ 0.2 in univariate analysis were imputed into the model as follows; age category, gender, having a smoking father, smoking sibling, smoking friend, other smoking relative, and use of alcohol. Age > 21, having a smoking father, and use of alcohol were significantly associated with being an ever-smoker. [Table 2] shows the multivariate logistic regression for the determinants of being an ever-smoker.
|Table 2: Multivariate logistic regression for factors associated with being an ever-smoker|
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Knowledge of smoking-related diseases and smoking cessation strategies
Cigarette smoking and passive smoking were thought to be harmful to health by 100% and 98.4% of the students, respectively. Similarly, cigarette smoking was thought to be addictive and was a risk factor for lung cancer by 99.2 and 99.6% of the students, respectively. A positive response with regards to other risk of cigarette smoking were as follows; emphysema 182 (72.8%), coronary artery disease 207 (82.8%), stroke 172 (68.8%), and low birth weight in children of smoking mothers 191 (76.4%). There was an association between class level and knowledge of these smoking-related diseases. Students in the clinical faculty had better knowledge than those in the preclinical faculty. [Table 3] compares the level of knowledge of the smoking-related diseases by faculty category.
|Table 3: Knowledge of some smoking-related conditions by faculty category|
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Regarding knowledge of smoking cessation therapy among the students; 193 (77.2%) students were aware of use of nicotine replacement therapy in smoking cessation, but only 103 (41.2%) were aware that certain antidepressant (bupropion or Zyban) could also be used for smoking cessation.
In response to the question on circumstances they would be willing to offer smoking cessation advice to patients who smoke; 249 (99.6%) would offer smoking cessation advice if a patient who smokes presents with a smoking-related disease and 249 (99.6%) only when their opinion is sought. However, 195 (78%) will offer smoking cessation advice if a smoker had no symptom of any smoking-related disease and does not seek their opinion about smoking. In addition, 98.8% thought that doctors have a role to play in tobacco control by offering smoking cessation advice, 83.2% thought doctors serve as nonsmoking role models for their patients and the public, and 88.4% thought that a patient's likelihood of quitting smoking is increased if a doctor advises him to quit. One hundred and fifty-five (62%) thought doctors who smoked were less likely to advise patients to stop smoking.
When asked if they possessed adequate knowledge and skills required to offer smoking cessation advice, 172 (68.8%) responded positively. In particular, 39 (78%) of the final year students believed they had adequate smoking cessation knowledge and skill. Two hundred and twenty-eight (91.2%) of all the students had received training on health hazards of smoking but 142 (56.8%) had formal training on smoking cessation techniques. Two hundred and thirty-one (92.4%) expressed the desire to have formal smoking cessation training included in their curriculum.
Attitude to tobacco control policies
The ban on cigarette smoking in enclosed public places was supported by 231 (92.4%) of the students and 228 (91.2%) supported the ban on sale of cigarette to persons younger than 18 years of age. However support for ban on cigarette advertisement and raising taxes on cigarette sales was recorded in 204 (81.6%) and 194 (77.6%) of the students, respectively.
| Discussion|| |
This study shows that there is a low prevalence of current smoking (1.2%) among medical students in Lagos. This is similar to more recent finding in Ibadan and Ilorin medical schools (3%) and contrasts the high prevalence rate of 65% (19% regular smokers, 46% experimental smokers) found in an earlier study at our institution in 1976. ,, The falling trend in the prevalence of cigarette smoking among medical students may be a reflection of the falling trend in the general population in Nigeria. According to the 2010 World Bank report, the prevalence of tobacco use (excluding smokeless tobacco) was 3% in females and 10% in males compared to 16% in the 2006 WHO report. ,, Among medical students, this reduction in prevalence may be attributed to the younger age of medical students attending the university now, compared to what obtained in the past (mean age 24 in 1976). In the 1976 study, Elegbeleye et al.,  found that medical students were older and most smokers were older than 24 years of age. Also, an increase in public campaign against cigarette smoking may have contributed to the reduction in prevalence of smoking. Public campaign has increased the awareness of dangers associated with cigarette smoking which has made smoking appear irresponsible among the general population and more especially for healthcare providers. The proliferation of religious activities within the university campus which generally deter adherents from smoking has also been proposed as a reason for the reduced prevalence among students.  All the students in our study had religious affiliations.
Considering gender distribution, the higher prevalence of ever smoking and current smoking among males in our study also follows the trend in other studies especially in Africa and Asia. ,, A survey of smoking habits among medical students from ten African countries showed a prevalence rate of 29% in males and 10% in females while in another Nigerian study, no female medical student smoked. , Social disapproval of smoking by women in these countries contributes largely to this difference and some female medical students who actually smoke may not admit their smoking habit for the same cultural reasons.  However, the proportion of female ever-smokers observed in our study is higher than that observed in the earlier study at our institution and this trend is in keeping with the narrowing gender gap as regards smoking prevalence observed internationally. 
Due to the limited number of current smokers in our study, the factors associated with cigarette smoking were assessed for all ever-smokers. We corroborated the observation that superior knowledge of the risks associated with cigarette smoking among senior medical students did not translate to a lower prevalence of smoking among them, compared to medical students in the lower classes. ,, This suggests that factors that influence initiating smoking, far outweigh the awareness of risk factors associated with cigarette smoking. Most smokers initiate smoking at a young age due to curiosity, peer pressure, and family influences but sustain the habit for other reasons such as intensification of pleasure in males, increased concentration, and a boost in social confidence in females. ,,
The significant determinants of smoking in our study are similar to the factors reported in earlier studies. Increasing age was significantly associated with ever smoking in the present study and was also observed in the earlier study at our institution, at that time more students above 24 years were smokers.  In a Chinese medical school study, where the prevalence of current smoking was quite high, age was also associated with smoking.  The reasons for this association may include the fact that older students are more independent, may have access to more spending money and can actually use this habit to demonstrate to their parents and other members of the society especially their friends that they are now mature.  The influence of parents and siblings as smoking role models for young people was also demonstrated in our study and corroborates the findings among undergraduate students in the University of Lagos, female secondary school students, and also among Japanese and Indian medical students. ,,, The use of alcohol and other psychoactive substances was substantial among our medical students and alcohol was significantly associated with cigarette smoking; an association that has also been earlier reported.  This finding highlights the need for expansion of tobacco control programs to include education on the health risks associated with use of alcohol and other psychoactive substances.
Our study demonstrated that there are significant gaps in the knowledge of medical students regarding smoking-related diseases and smoking cessation strategies. This deficiency in knowledge has been observed in other medical schools worldwide and points out a deficiency in the medical curriculum which appears to be focused on treatment-based medical training with less emphasis on disease prevention. ,,, The gap in the curriculum was further demonstrated by the fact that most students including those in our study accept the role of doctors as nonsmoking role models but are unwilling to offer smoking cessation advice readily to smoking patients who do not have any smoking-related disease. ,,, In a study of first and fifth year medical students in Tunisia, 65.8% strongly agreed that it was the doctors' responsibility to convince other people to stop smoking; 70.8% strongly agreed that doctors should set a good example by not smoking, but 72.3% of the students would not advice a patient to stop smoking if the patient had no smoking-related symptoms and did not raise the question about smoking cessation.  As observed in our study, the reluctance to offer smoking cessation advice stems from the fact that the students believed that they had inadequate knowledge and skill to counsel patients adequately. ,, The Tunisian study also found that only 39.5% of the students thought they were qualified to counsel patients on smoking.  It is therefore evident that medical students have insufficient knowledge of smoking-related diseases and smoking cessation methods, and this is likely due to failure of medical schools to provide formal training on tobacco to their students. Only about half of our students reported receiving any formal training on smoking cessation and this was corroborated in the GHPS survey which showed that only 1.4-43.5% of medical students worldwide had ever received any formal training in smoking cessation. 
Doctors are expected to be advocates of tobacco control programs and the students in our study exhibited a good attitude towards it, similar to medical students at the University of Ibadan. This implies that the students are willing to support the government in implementing tobacco control policies but unfortunately, the tobacco control act is yet to be signed into law in Nigeria.
An observed limitation in our study is the use of self-report in determining smoking prevalence. Self-reported smoking sometimes may be an unreliable means of determining smoking prevalence as smokers generally are inclined to underestimate or underreport the quantity of cigarettes smoked or may deny smoking altogether due to the perceived social disapproval. , Further studies among students should aim to validate the prevalence of smoking obtained by self-report by comparing it with the prevalence obtained by biochemical assessment of markers of current smoking such as cotinine.
In conclusion, the prevalence of current cigarette smoking among medical students in Lagos, Nigeria is quite low and shows a marked reduction in comparison to an earlier study at the same institution. Gaps exist in the knowledge of the students with regard to risks of cigarette smoking and tobacco cessation strategies and in their attitude and behavior towards offering tobacco cessation advice. However, there is a good attitude towards supporting tobacco control policies. There is need therefore to include formal training on tobacco control strategies including the risk of cigarette smoking at an early stage in the medical curriculum.
| References|| |
American Lung Association. International tobacco use fact sheet, 2008. Available from: www.lungusa.org
[Last accessed on 2009 Oct].
Degenhardt L, Chiu WT, Sampson N, Kessler RC, Anthony JC, Angermeyer M, et al
. Toward a global view of alcohol, tobacco, cannabis, and cocaine use: Findings from the WHO World Mental Health Surveys. PLoS Med 2008;5:e141.
Desalu OO, Olokoba AB, Danburam A, Salawu F, Issa BM. Epidemiology of tobacco smoking among adult population in North East Nigeria. Internet J Epidemiol 2008;6:1.
World Health Organization. Code of practice on tobacco control for health professional organizations. Geneva: World Health Organization; 2004. [Last accessed on 2010 Oct].
Bandele EO, Osadiaye JA. Attitudes and smoking habits of physicians at the Lagos University Teaching Hospital. J Natl Med Assoc 1987;79:430-2.
Okeke TA. Smoking habits of physicians in Enugu, Nigeria. J Community Med Prim Health Care 2004;16:34-8.
Kawakami M, Nakamura S, Fumimoto H, Takizawa J, Baba M. Relation between smoking status of physicians and their enthusiasm to offer smoking cessation advice. Intern Med 1997;36:162-5.
Dekker HM, Looman CW, Adriaanse HP, van der Maas PJ. Prevalence of smoking in physicians and medical students, and the generation effect in the Netherlands. Soc Sci Med 1993;36:817-22.
Smith DR, Leggat PA. An international review of tobacco smoking among medical students. J Postgrad Med 2007;53:55-62.
Faseru B, Barengo NC, Sandström HP, Omokhodion F. Smoking behaviour and perception of risk among medical students in Ibadan, Nigeria. Prev Control 2006;2:103-9.
Makanjuola AB, Daramola TO, Obembe AO. Psychoactive substance use among medical students in a Nigerian university. World Psychiatry 2007;6:112-4.
Ihezue UH. Drug abuse among medical students at a Nigerian University: Part 1. Prevalence and pattern of use. J Natl Med Assoc 1988;80:81-5.
Alakija W. Smoking habits of medical students of the University of Benin, Nigeria. Nig Med J 1984;14:171-4.
Elegbeleye OO, Femi-Pearse D. Incidence and variables contributing to onset of cigarette smoking among secondary school children and medical students in Lagos Nigeria. Brit J Prev Soc Med 1976;3:66-70.
Richmond R. Teaching medical students about tobacco. Thorax 1999;54:70-8.
Sreeramareddy CT, Suri S, Menezes RG, Kumar HN, Rahman M, Islam MR, et al
. Self-reported tobacco smoking practices among medical students and their perceptions towards training about tobacco smoking in medical curricula: A cross-sectional, questionnaire survey in Malaysia, India, Pakistan, Nepal, and Bangladesh. Subst Abuse Treat Prev Policy 2010;5:29.
Bandele EO, Osadiaye JA. Certain variables contributing to onset of cigarette smoking among young Nigerians. Proceedings of the World Conference on Tobacco and Health. 1990; 525-8.
Xiang H, Wang Z, Stallones L, Yu S, Gimbel HW, Yang P. Cigarette smoking among medical college students in Wuhan, People′s Republic of China. Prev Med 1999;29:210-5.
Awotedu AA, Jordaan ER, Ndukwana OZ, Fipaza NO, Awotedu KO, Martinez J, et al
. The smoking habits, attitudes towards smoking and knowledge regarding anti-smoking legislation of students in institutions of higher learning in the Eastern Cape Province of South Africa. SA Fam Pract 2006;48:14-14d.
Ele PU, Ibeh CC. Influence of family and social ties on cigarette smoking in young Nigerian female. Indian J Allergy Asthma Immunol 2001;15:97-101.
Tamaki T, Kaneita Y, Ohida T, Yokoyama E, Osaki Y, Kanda H, et al
. Prevalence of and factors associated with smoking among Japanese medical students. J Epidemiol 2010;20:339-45.
Ganesh Kumar S, Subba SH, Unnikrishnan B, Jain A, Badiger S. Prevalence and factors associated with current smoking among medical students in coastal South India. Kathmandu Univ Med J (KUMJ) 2011;9:233-7.
Warren CW ,
Jones NR, Chauvin J, Peruga A, GTSS Collaborative Group. Tobacco use and cessation counselling: Csross-country. Data from the Global Health Professions Student Survey (GHPSS), 2005-7. Tob Control 2008;17:238-47.
Mostafa SR, Shokeir NF. Smoking-related behavior and attitudes among medical students in Alexandria. J Egypt Public Health Assoc 2002;77:1-28.
Harrabi I, Ghannem H, Kacem M, Gaha R, Ben Abdelaziz A, Tessier JF. Medical students and tobacco in 2004: A survey in Sousse, Tunisia. Int J Tuberc Lung Dis 2006;10:328-32.
Patrick DL, Cheadle A, Thompson DC, Diehr P, Koepsell T, Kinne S. The validity of self-reported smoking: A review and meta-analysis. Am J Public Health 1994;84:1086-93.
Connor Gorber S, Schofield-Hurwitz S, Hardt J, Levasseur G, Tremblay M. The accuracy of self-reported smoking: A systematic review of the relationship between self-reported and cotinine-assessed smoking status. Nicotine Tob Res 2009;11:12-24.
[Table 1], [Table 2], [Table 3]