according to the world health organization reports ( who ) , 22% of the world 's population aged over 15 years are smokers and approximately six million people die from tobacco use or exposure to tobacco smoke .
studies in iran show that about 26% of the iranian men and 3.6% of the women participating in the study are current smokers ( 1 ) .
unfortunately , the prevalence of smoking between college students is higher than in the general population in iran . with a cross - sectional population - based study , fotouhi et al . reported that prevalence of smoking in residents of tehran , capital of iran , is 12% ( 2 ) . on the other hand , jafari et al
. found that among the students of tehran university , 35.4% of men and 12.6% of women are smokers ( 3 ) .
the high prevalence of smoking ( 42.5% ) among university students was also reported by other investigators in the middle - east countries ( 4 ) .
cigarette use among medical students is of particular concern because medically educated persons play a leading role in the development of overall public health policy and the prevention of tobacco use in the society . in some studies on medical students in the developed countries ,
on the other hand , a multi - country survey in the developing countries revealed a smoking prevalence rate of 11% , 6.7% , 10.6% , 17.8% and 17.4% among medical students of malaysia , india , pakistan , nepal and bangladesh , respectively ( 9 ) .
although many researches are conducted in different countries , there have been few researches on cigarette smoking in iran .
nazary et al . studied the prevalence of smoking among male students in semnan university of medical sciences , iran , and found a smoking rate of 14.4% ( 10 ) . in another study ,
ahmadi et al . assessed the prevalence of cigarette smoking among students of shiraz university of medical sciences .
the internship students showed the highest prevalence of smoking ( 17% ) among the medical students ( 11 ) .
the preliminary studies highlight the need for performing more investigations on the prevalence and determinants of tobacco use and developing effective cessation interventions for health professional students .
the current study aimed to investigate the prevalence of active cigarette smoking , socio - demographic data , knowledge and attitudes about cigarette use , exposure to second - hand tobacco smoke , attitude of willingness to stop smoking , etc . among health professional students in mums , mashhad , iran .
the current cross - sectional study was conducted on the students of six faculties of mums ( dentistry , medicine , midwifery and nursing , pharmacy , paramedical sciences and public health ) in autumn ( october and november ) 2008 . a standard self - administered questionnaire adopted from the global health professional survey ( ghps ) , designed for health professionals by the who and the canadian public health association was used in this study ( 12 ) .
the inclusion criteria for the analysis were ( a ) student status , ( b ) age between 18 and 28 years , ( c ) consent to participate in the survey , and ( d ) no missing data for the tobacco - related variables .
a total of 936 students met these criteria and completed the information ( about 85% ) .
informed consent was obtained from each participant included in the study and the study protocol conformed to the ethical guidelines of the 1975 helsinki declaration .
ethical approval was granted by mums ethics committee prior to the data collection ( ethical approval code : 87685 ) . the study proposal and instruments
, the students were informed that the information collected would be kept anonymous and that participation was completely voluntary .
the questionnaire was designed in three parts ; the first part consisted of socio - demographic data ( age , sex , health professional discipline , marital status and ethnicity ) , smoking status of their father / mother / other family members , daily exposure to cigarette smoking and participant smoking status ( current smokers including daily smokers and occasional smokers and former smokers ) . the second part of the questionnaire included the data on attitudes towards using or not using cigarettes , age of the smoking onset , reasons to start smoking , reasons to continue smoking , number of cigarettes smoked per day , duration of smoking , places most commonly smoked in , and the number of quit attempts .
the third part included the questions regarding the cigarette advertisements and prohibitions , awareness of cigarette negative effects and reasons , smoking cessation , and the reaction of participant in places where there are people who smoke .
in accordance with the who guidelines , the students were categorized as daily smokers , occasional smokers , former smokers or nonsmokers .
daily smokers were defined as those who smoked at least one cigarette per day for at least one month before completing the questionnaire ; occasional smokers were defined as those who did not smoke daily ; former smokers ( ex - smokers ) were defined as those who previously had a daily smoking habit for a continuous period of six months but had given up smoking at least one month prior to completion of the questionnaire ; and nonsmokers were defined as those who had never smoked or who had been smoking for less than one month .
descriptive data analysis was performed using statistical package for the social sciences ( spss ) version 17.0 .
the independent effect of individual factors , multiple logistic regression analysis was used and odds ratio ( or ) with 95% cis were computed .
among all 936 students included in the study , 44.6% were male and 55.4% were female ( table 1 ) .
the effects of various independent variables on the prevalence rate of cigarette smoking were investigated , and odds ratios were calculated . the overall prevalence of cigarette smoking was 9.8% with significant differences in prevalence by gender ; 17.6% among males and 4.2% among females (  70.57 ; p < 0.001 ) .
prevalence of smoking did not significantly change according to the year of study : first year , 7% ; second year , 8% ; third year,8.3% ; fourth year , 17% ; fifth year , 11% ; sixth year , 20% ; seventh and over , 6.7% (  3.49 ; p > 0.05 ) .
also , the mean age of starting cigarette was 19.6  2.5 and 18.9  2.4 years for male and female students , respectively . among all students , 18.3% ( 95% ci 8.2 - 15.4 ) reported never having tried or experienced cigarette smoking .
the prevalence of daily , occasional and former smokers was 9.8% , 3% and 5% , respectively ( table 2 ) .
also , analysis of data showed that men were significantly more likely to become daily smokers than women ( 18.9% vs. 2.5% ; p < 0.001 ;  70.57 ) . the onset age of female students who smoked regularly was 18.9  2.4 years , lower but not statistically significant compared to that of male students ( 19.6  2.56 years ) .
most of the men ( 26.6% ) and women ( 44.5% ) were smokers for more than four years ( table 3 ) .
also , it was found that 50% of the students had smokers in their family , father , mother , brother or sister ( table 4 ) .
the most common reasons to start smoking were ranked as follows : friends ( 24.9% ) , distress and anxiety due to dormitory residency ( 23% ) or pleasure and fun ( 22.8% ) . on the other hands , the most important reasons to continue
most of the smokers ( 53% ) reported that they achieved their goals set prior to the onset of smoking and 18.5% of smokers believed that cigarette smoking was not helpful to achieve their goals , while 28.4% had no knowledge about it .
the number of cigarettes per day was 1 - 5 , 6 - 10 , 11 - 15 , and 16 - 20 cigarettes in 25% , 32% , 17.7% and 25.5% of smokers , respectively .
favorite smoking places were as follows : parks and campus ( 37.8% ) , dormitory ( 18% ) , no particular places ( 9.4% ) , at parties ( 8% ) and bath room ( 7.1% ) .
the majority of participants ( 92.3% ) reported that they were aware of the hazards of smoking . a significant difference regarding awareness of smoking hazards
was observed between smokers and non - smokers (  604.17 ; p < 0.001 ) . significant gender differences (  11.11 , p <
females ( 97.9% ) were more likely to agree with smoking hazard effects on health than males ( 85.5% ) . in the current study
, 5% of the participants reported that they have a history of successfully quitting cigarette smoking .
they believed that the nisus ( 50% ) was the most important reason to quit smoking .
better knowledge about dangerous effects of cigarette smoking on health ( 27.8% ) and caring for one s own health ( 11% ) were the most important reasons to quit smoking . among the smokers ,
90% intended to quit smoking , 45.4% had tried to quit smoking without any success , and 54.6% believed themselves able to quit smoking .
all of the nonsmokers stated that they avoided environments where people were smoking , because of complications like respiratory distress ( 60.6% ) , hatred toward smoking persons ( 55.8% ) , headache ( 42.5% ) and other problems such as nausea and vomiting , coughing and tearing .
the most important preventive factors upon cigarette smoking were as follows : religious beliefs ( 70% ) , parents ( 40.2% ) , knowledge about cigarette - induced health problems ( 33.4% ) , information from mass media about the hazards of smoking ( 19% ) , and close friends ( 18.7% ) .  
the collected data showed that cigarette smoking was common ( 10% ) among medical students in mashhad .
previous studies in other cities of iran revealed that prevalence of smoking was 9% , 6% , 11% and 7.4% in shiraz , golestan , kerman and ardabil universities of medical sciences , respectively ( 13 - 16 ) .
therefore , it seems that the prevalence of smoking among iranian health professional students is approximately in the range of 6% to 11%
. regarding the other countries in the middle - east , approximately similar prevalence ( 11% ) was found by almerie et al . among the medical students of syria ( 17 ) . on the other hand ,
other researchers reported different incidence of smoking among medical students in the united state ( 20% ) , germany ( 25% ) , turkey ( 22% ) , brazil ( 16.5% ) , jordan ( 28.6 ) and hong kong ( 0.7% ) ( 5 - 8 , 18 , 19 ) .
therefore , the prevalence of tobacco smoking in the current sample is still lower than those of medical students in many other countries
. also , a cross - country , cross - sectional study among 12 medical schools in four countries in europe ( germany , italy , poland and spain ) found that the overall prevalence of smoking among medical students ( almost 30% ) was higher than the general population ( 20 ) . on the other hand ,
the rate of regular smokers in the mums is relatively smaller than that of general population in mashhad city ( 12.7% ) described by boskabady et al .
according to the current study data , the prevalence of smokers in male students was more than females . besides , the study found that in mashhad city , the prevalence of female smokers in students of medical sciences was 17.6% which is markedly higher than that of general population ( 1.7% ) reported by boskabady et al .
therefore , this point emphasized the necessity for a quit - smoking plan and a more active approach to prevent smoking among female medical students .
moreover , the average age of starting smoking in the current sample was almost 19 years , which is two years lower than that of general population in mashhad and shiraz cities , iran ( 1 , 22 ) .
the smoking onset age indicates that most of the participants started smoking after attending the university . in the current study ,
the most common reason to start smoking was friends . in agreement with the current study findings ,
previous studies on medical students in japan and albania also reported that friends were the most important factor associated with smoking behavior ( 22 , 23 ) .
also in the current study student sample about 50% of the participants had smokers in their family , which again emphasizes on the important role of relatives and friends on starting cigarette smoking .
more prevalence of smoking in some ethnicities , particularly turk and lor , emphasizes on identifying the ethnicity and cultural factors which influence the smoking behavior and probably manifests the lower knowledge of these groups regarding smoking complications .
sixth - year students had higher prevalence of smoking ( 20% ) than the students in the other study years .
therefore , it seems that the students in the last years of education need a specific training regarding smoking cessation .
understanding the prevalence and the factors associated with cigarette use among the health professional students is of particular concern because medically educated persons play a leading role in the development of overall public health policy and prevention of tobacco use in the society .
thus , this understanding will aid to design tobacco / substance abuse prevention and control activities in the populations .
regarding sampling , in order to include as many students as possible , the questionnaires were distributed to the students in dormitories .
living without parents ( in dormitories ) is accompanied with freedom of previous limitations which can be associated with some changes in individual s life ( 3 ) .
therefore , the prevalence of smoking among the students living in dormitories may not be exactly the same as the general population of mums students . also , under - reporting of smoking was possible , because health professional students may be more sensitized than the other populations to reporting their smoking habits ( 18 , 24 ) .
in addition , the study used a cross - sectional design to collect data on smoking behavior and related factors and possible bias could have occurred .
smoking among medical students and health professionals is a serious concern because they should play important roles in smoking prevention and in assisting patients to quit smoking .
this indicated the necessity of much more attention to educate the health professional students . in conclusion , although the prevalence of regular smokers among health professions students of mums was lower than those of the general populations , this level was still alarming and pointed at the rapid growth towards cigarette use , especially among female students . medical schools should work harder to tackle this phenomenon and address it more efficiently in their curricula .
 background : tobacco consumption is the second major cause of death and the fourth most common risk factor for diseases , worldwide . 
 epidemiologic studies have traced the use of alcohol , tobacco , and illicit substances among medical students and physicians.objectives:the current study aimed to investigate the prevalence of cigarette smoking and the related factors among the students of medical sciences in mashhad university of medical sciences , mashhad , iran.patients and methods : this cross - sectional study was conducted on 946 health professional students in mashhad university of medical sciences ( mums , iran ) in autumn 2008 . 
 a standard self - administered questionnaire consisting of socio - demographic data , participant smoking status , family and peer smoking , attitudes and beliefs about smoking , awareness of cigarette negative effects and reasons for smoking cessation was used in the current study.results:among the students , 18.3% reported having ever tried or experienced with cigarette smoking . 
 the overall prevalence of cigarette smoking was 9.8% with significant differences in prevalence rates by gender , 17.6% among males and 4.2% among females . 
 starting and continuing smoking was significantly correlated with the family cigarette consumption habits . 
 the most common reason to start smoking was friends ( 24.9% ) and the most important reason to continue smoking was personal life distress ( 17.6% ) . 
 the majority of participants ( 92.3% ) reported that they were aware of the hazards of smoking . 
 a significant difference regarding awareness of smoking hazards was observed between smokers and non - smokers . the most important preventive factor for cigarette smoking was religious beliefs ( 69.1%).conclusions : although the prevalence of regular smokers among health professions students of mums was lower than general populations , but this level is still alarming and points at the rapid growth of cigarette use , especially among female students . 
 medical schools should work harder to tackle this phenomenon and address it more efficiently in their curricula . 
1. Background
2. Objectives
3. Patients and Methods
4. Results
5. Discussion