Smoking is an important reversible cause of morbidity and mortality in the modern world, with the World Health Organization (WHO) expecting one billion smoking-related deaths in the 21st century. Smoking is a serious public health threat, even among developed European countries [1
] where intensive tobacco control measures have been implemented in recent years. The currently available smoking cessation medications have limited success. Nicotine substitutes have smoking cessation rates below 7% at 1 year [3
], although combination therapy with multiple nicotine replacement products may be more effective [5
]. Oral medications have less than 20% success rate in well-organized clinical studies [6
], and are usually less effective in everyday clinical practice [7
]. As a result, smoking prevalence remains high, with the latest data estimating that, in 2014, 26% of the population >15 years in the European Union (EU) smokes [2
], compared to 28% in 2012 [8
The situation in Greece concerning smoking is particularly worrisome, with 38% of the population smoking in 2014 [2
] compared to 40% in 2012 [8
]. This is happening despite the intense efforts of the local tobacco control community and regulators, which has resulted in the implementation of public places smoke-free laws, warnings on tobacco cigarette packaging and media campaigns educating the population about the adverse effects of smoking. Additionally, a network of specialized smoking cessation clinics (in both public and private healthcare sectors) has been developed, which is mainly managed by respiratory physicians and, to a somewhat lesser extent, by cardiologists.
Tobacco harm-reduction, a strategy of providing less harmful alternative products to smokers to substitute the use of combustible tobacco, have been developed in an effort to accelerate the reduction in smoking prevalence and reduce smoking-related disease and death [9
]. This is based on the fact that nicotine, although contributing to dependence, is of low health-harm potential when obtained through a non-combustible product. According to the International Agency for Research on Cancer (IARC), nicotine is not classified as a carcinogen [10
]. Several laboratory studies have identified a tumor-promoting effect of nicotine [11
] as well as an effect on atherosclerosis [13
]. However, clinical studies have failed to reproduce these findings. The Lung Health Study followed up a cohort of 3320 users of nicotine replacement therapy (nicotine gum) for 7.5 years and found that smoking, but not nicotine replacement therapy, was a predictor of lung cancer [15
]. The same study group found that, after 5 years of follow-up, use of nicotine gum was not associated with higher rates of hospitalizations for cardiovascular conditions and cardiovascular deaths [16
]. A recent metanalysis of the cardiovascular effects of smoking cessation pharmacotherapies evaluated 21 randomized controlled trials of nicotine replacement therapies and found an elevated risk of all cardiovascular events which was driven predominantly by less serious events, mainly tachycardia [17
]. More extensive epidemiological data on the association between nicotine intake and cancer or cardiovascular disease are available from studying snus use. Snus users obtain equal or higher amounts of nicotine on a daily basis compared to smokers [18
]. However, snus use, especially Scandinavian snus which is a low-nitrosamine smokeless tobacco product, carries a very low risk of developing cancer compared to smoking. Luo et al.
found that the risk of oral and lung cancer among snus users was similar to never smokers, while only pancreatic cancer risk was elevated in current snus users and those using more than 10 grams per day [20
]. A systematic review of the relation between snus use and cancer concluded that, if all smoking population was instead using snus, only 1.1% of the smoking-attributed cancers would occur [21
], showing that the risk for cancer is higher than non-use but minimal compared to smoking. Similar evidence exists for the association between snus use and cardiovascular disease. A retrospective case control study in Sweden found that the risk for acute myocardial infarction was similar between snus users and never smokers [22
]. An analysis of eight prospective studies also found no association between snus use and acute myocardial infarction [23
]. Similarly, an analysis of eight prospective cohort studies on stroke risk (ischemic and hemorrhagic), with more than 130,000 non-smoking men participating, found no association between snus use and risk of stroke [24
]. These studies have shown that nicotine is highly unlikely to contribute significantly to smoking-related cancer and cardiovascular disease.
Electronic cigarettes are the latest addition in tobacco harm reduction [25
]. These battery devices produce an aerosol by heating a liquid which may contain nicotine and other food-approved ingredients, including flavors; the aerosol is subsequently inhaled by the user. Despite the lack of long-term epidemiological studies, currently-available evidence from chemistry, toxicology and few short-term clinical studies suggests that electronic cigarettes are by far less harmful than smoking [26
]. This is mostly related to the lack of combustion and the low temperatures of evaporation, resulting in far lower toxic emissions compared to tobacco cigarette smoke [28
]. The efficacy of electronic cigarettes on smoking cessation has been questioned. Two randomized controlled trials have shown a small effect of electronic cigarettes on smoking cessation [31
]. However, both used outdated and ineffective products. Moreover, the design of randomized controlled trials, which dictates the use of a single product by all participants, may be inappropriate to evaluate the overall efficacy of electronic cigarettes on smoking cessation considering that switching from smoking to electronic cigarette use is related to a behavioral change and that there is a huge variability of electronic cigarette products which are selected by users based on self-preference. A recent study using more advanced products showed substantially higher cessation rate [33
], while a population study in the UK showed that they are substantially more effective compared to nicotine replacement therapies [34
The role of healthcare professionals in properly advising and guiding the smoking population has long been established. A meta-analysis of 31 studies which included over 26,000 smokers found that even brief advice increased the chances of smoking cessation [35
]. Another meta-analysis concluded that counseling of smokers by nurses increases the chances of quitting by 29% [36
]. A prerequisite for effective counseling to smokers is proper education and knowledge of healthcare professionals about the effects of smoking on health and about all the available methods and products that could contribute to smoking reduction or cessation. Healthcare professionals are the most important source of information about the relative risks of different products for smokers, due to the respect and corresponding confidence enjoyed by society. Current evidence shows that the knowledge and concepts of healthcare professionals about smoking and nicotine are not always appropriate and science-based. A study of physicians from UK and Sweden showed that a large proportion (40%) of respondents incorrectly believed that nicotine was the most important or second most important cause of smoking-related disease [37
]. This can have negative effects on the management of smokers. For example, it could discourage smokers from using pharmaceutical nicotine preparations or other nicotine-containing products which are less harmful than smoking. Studies in Norway and in other countries showed that the population overestimates the harmful effects of smokeless tobacco (snus) [38
] and nicotine replacement therapies [41
] compared to smoking, and this seems to be related to misconceptions about the relative risks of different products by healthcare professionals [42
Considering the exponential growth in awareness and use of electronic cigarettes over the past few years [43
], it is expected that, over time, more smokers will seek advice from healthcare professionals about these alternative to smoking products. Therefore, the purpose of this study was to evaluate the concepts and beliefs of a convenient sample of Greek healthcare professionals about nicotine, nicotine replacement therapies and electronic cigarettes through an online questionnaire.
A questionnaire was developed by the researchers and was uploaded to an online survey tool (www.surveymonkey.com
). Initially, participants had to read a brief presentation of the research purpose and agree to an informed consent. Then they were transferred to the questions of the survey. The questionnaire had five main sections, asking for information about: (1) demographics of the participants, including age, gender, profession, working time and working sector (public or private); (2) smoking status of the participants; (3) perceptions and knowledge about the contribution of nicotine to smoking-related disease; (4) knowledge about the efficacy and dependence potential of nicotine replacement therapies, and; (5) knowledge about electronic cigarettes. Concerning nicotine, the main purpose was to evaluate the perceived relative risk of nicotine exposure compared to exposure to other smoking-related toxins, and its contribution to smoking-related disease. For nicotine replacement therapies, questions were mainly focused on the willingness to propose the long-term use as smoking substitutes (as suggested by recent guidelines [45
]), their dependence potential compared to smoking and the knowledge about their efficacy in smoking cessation. Since electronic cigarettes are novel products, our purpose was to evaluate the knowledge about their functional and design characteristics, nicotine source in e-liquids and pending EU regulation, and evaluate whether healthcare professionals would recommend them as a substitute for smoking in those unable or unwilling to quit with other methods. Finally, participants were asked to report what they would consider appropriate regulation for electronic cigarettes. The questionnaire of the survey is presented in Supplementary materials
. To improve the questionnaire design and ensure the comprehension of the survey items, five healthcare professionals (two cardiologists, one respiratory physician, one general practitioner and one nurse) were recruited and the assessment of the questionnaire was performed using the method of cognitive interviewing [48
]. This process occurred before the questionnaire was released online. The study was approved by the ethics committee of the National School of Public Health in Athens, Greece (Ethics Committee Approval Code: 1701/16-12-2014). The questionnaire was anonymous and participants were informed through the consent form that they could exit the questionnaire at any time. The IP addresses were recorded with the only purpose to remove double entries.
A personal invitation to participate, together with the link to the questionnaire, was sent by email to a convenient sample of physicians and nurses working at the seven largest (in terms of bed capacity) hospitals and eight primary care centers located in Athens, Greece. Additionally, private practice physicians and nurses were selected through online search tools. The purpose of the hospitals and primary care centers selection was to cover all major districts of Athens, while private practice physicians and nurses were selected from the same areas. In an effort to balance the selection process, a similar number of public and private sector professionals were invited from each Athens district. The selection was based on availability of email addresses, and no other communication tool (telephone, personal contact) was used for survey participation. A total of 865 healthcare professionals were contacted. For physicians, general practitioners, cardiologists, dentists, internists, pediatricians and respiratory physicians were asked to participate. The main reasons for recruiting cardiologists and respiratory physicians were that they treat the most common smoking-related diseases (cardiovascular and respiratory diseases) and that they are directing smoking cessation centers in Greece. Other specializations were also selected based on their interaction with smokers and smoking-related disease. The only exclusion criteria were not responding to the question about occupation (Supplementary materials, question 3
) and responding to less than 80% of the questions.
Results were reported for the whole sample, with categorical variables presented as number (%) and continuous variables as mean (SD). Subsequently, comparisons were made between smokers (current and former) and never-smokers, between physicians and nurses and between a subgroup of physicians working in tobacco cessation in Greece (cardiologists and respiratory physicians) and all other participating healthcare professionals. The reason for dividing the sample into these subgroups is related to the expectation that smokers would have better knowledge about the study subject due to personal experience and use, physicians would be better educated about health issues related to smoking and cardiologists and respiratory physicians would also be better educated since they are responsible for treating the major causes of smoking-related morbidity and mortality and they manage the smoking cessation clinics in Greece. Comparisons between groups were performed with independent-samples t
-test, one way ANOVA and χ2
test. A “knowledge score” was calculated for each participant, by scoring 1 point for every correct answer of the participants in some of the questions (see Supplementary materials
). Univariate and multivariate linear regression analysis was performed to explore the association between the knowledge score and various characteristics of the study participants. All variables with p
< 0.05 in univariate analysis were included in the multivariate model. A p
value of <0.05 was considered statistically significant and all analyses were performed with commercially available software (SPSS v22.0, Chicago, IL, USA).
3.1. Descriptive Analysis of the Study Sample
The results of the descriptive analysis of the whole study sample are shown in Table 1
. From the 865 healthcare professionals invited, 316 entered the survey questionnaire. After excluding double entries (through the IP addresses), rejections to the informed consent, participants not responding to the question about profession and participants responding to less than 80% of the questions, a total of 262 subjects (77 were nurses and 185 were physicians) were included in the analysis (response rate of 30.3%). Healthcare professionals from all hospitals and primary care centers participated in the study. There was no statistical difference in gender, profession and working sector between the participants and those who were excluded or did not enter the survey. Most physicians were cardiologists, followed by respiratory physicians. More than half of the participants were working in the public healthcare sector, while the average working time was 12 years. The vast majority said they had daily contact with smoking patients in their working environment, while a high proportion considered they had very of fairly high level of knowledge about smoking. More than 50% were current or former smokers. Among former smokers, most had stopped smoking without the use of any aid, while seven participants reported smoking cessation with the use of electronic cigarettes.
Participants were asked to score the risk for several tobacco and alternative products, using a scale from 1 (minimum risk) to 10 (maximum risk). The following products were listed: tobacco cigarettes, snus, electronic cigarettes, nicotine replacement therapies and oral smoking cessation medications. Significant differences were found in risk scores among different products (p < 0.001). As expected, participants gave the highest risk score to tobacco cigarettes. The risk score for snus was very close to that of tobacco cigarettes while the risk score for electronic cigarettes was lower than both tobacco cigarettes and snus. Nicotine replacement therapies and oral smoking cessation medications had the lowest scores, with no statistically significant difference between them.
Participants were also asked to score the risk from several tobacco cigarette components, again using a scale from 1 (minimum risk) to 10 (maximum risk). The following components were listed: nicotine, inhaled smoke, carbon monoxide, tar and tobacco. Statistically significant differences were observed in risk scores among the different components (p < 0.001). The highest score was recorded for tar while slightly lower scores were given for smoke and carbon monoxide, without statistically significant difference between them. The risk score for nicotine was 8.0 (2.1) and was ranked 4th in terms of risk among the five components of smoking listed. Tobacco was considered by the participants as the component with the lowest risk.
More than half of the participants reported that nicotine has an extremely or very important contribution to the development of smoking-related diseases, mainly lung cancer and atherosclerosis, while approximately 45% considered extremely or very important the contribution of nicotine to the development of cancer to other than the lung organs. Almost four out of five participants considered nicotine replacement therapies less harmful than smoking; 6.5% said they did not know and 17.0% considered them equally or more harmful than smoking. About one out of three participants considered nicotine replacement therapies more addictive than smoking. Participants overestimated the efficacy of nicotine replacement therapies on smoking cessation, with just 23% correctly responding that their success rate is less than 10% at one year. The vast majority believed that nicotine in nicotine replacement therapies is synthetically-produced rather than extracted from the tobacco plant. Only one out of five participants would recommend the long-term (over 6 months) use of nicotine replacement therapies as an aid to reduce or quit smoking.
Concerning electronic cigarettes, one out of three participants reported that they have recommended the use of the electronic cigarettes to smokers in the past. The majority believed that electronic cigarettes are less harmful than smoking; only 1.5% of the participants considered them more harmful than smoking. Almost half, however, considered electronic cigarettes equally or more addictive than smoking. As with nicotine replacement therapies, most participants thought that the nicotine present in electronic cigarettes is synthetically-produced. One out of three believed that electronic cigarettes involve combustion, while the majority believed that the ingredients are approved for inhalational use. More than half reported they would recommend electronic cigarette use to smokers who have failed to stop smoking by other means, while about 55% would also recommend it to smokers who refuse to use pharmaceutical methods for smoking cessation. Ιt was noteworthy that less than 15% of the respondents knew the EU legislation on electronic cigarettes. The majority believed that electronic cigarettes sales to minors should be banned, while about 40% recommended to ban nicotine, ban advertising, be licensed as pharmaceutical products and include a warning on the label that they are equally harmful to smoking.
3.2. Comparison between Smoking and Never Smoking Participants
The results of the comparison between smoking (current and former) and never smoking participants are presented in Table 2
. There was no difference between groups in the number of physicians and nurses, working time and the frequency of contact with smokers at work. Small differences were observed in the responses between the two groups. Specifically, never smokers gave higher risk score to snus and nicotine compared to smokers, although both groups gave a fairly high risk score. Similar perceptions about the contribution of nicotine to smoking-related disease, the dependence potential of nicotine replacement therapies and electronic cigarettes and the origin of nicotine in replacement therapies and electronic cigarettes were observed in both groups. More never smokers compared to smokers supported the ban of nicotine use in electronic cigarettes, while more smokers supported the ban of flavors.
3.3. Comparison Between Physicians and Nurses
The results of the comparison between physicians and nurses are presented in Table 3
. Physicians were older and had more working time than nurses. More nurses were current smokers compared to physicians. Physicians reported a better level of information about smoking. Both groups, however, reported mostly very or fairly high level of knowledge about smoking.
Significant differences were observed between the two groups in their responses. Physicians gave higher risk scores to conventional cigarettes and lower to nicotine replacement therapies and oral smoking cessation medications compared to nurses. They also gave a lower risk score to nicotine and a higher score to inhaled smoke. Nicotine was ranked fourth by physicians in terms of the risk among all components of smoking listed, while nurses ranked nicotine third, with a slightly higher risk score compared to inhaled smoke. More nurses considered extremely or very important the contribution of nicotine to the development of smoking-related diseases compared with physicians. More physicians than nurses considered that nicotine replacement therapies were associated with lower health risk compared to smoking. Both groups overestimated the smoking cessation rates of nicotine replacement therapies and thought that nicotine in these products is synthetically produced rather than extracted from the tobacco plant. A greater proportion of physicians compared to nurses would recommend the long-term use of nicotine replacement therapies, although the rates were very low in both groups. About one out of three participants in both groups had recommended electronic cigarette use to smokers in the past; however, more nurses compared to physicians would recommend electronic cigarettes as smoking substitutes for smokers who are not willing to use other smoking cessation aids. More nurses than physicians believed erroneously that electronic cigarettes contain chemical additives approved for inhalation and that established quality certificates exist. More physicians than nurses suggested bans on electronic cigarettes use in public places as well as bans in advertising. Finally, more physicians than nurses said they knew the EU legislation on electronic cigarettes, although the rate of knowledge in both groups was extremely low.
3.4. Responses by Cardiologists and Respiratory Physicians
The responses of cardiologists and respiratory physicians compared to all other healthcare professionals are presented in Table 4
. Participants of the former subgroup were older and had more working time. They also had more frequent contact with smokers in their working environment and reported better level of information about smoking, while fewer were current smokers.
Significant differences were observed between the two groups in their responses. Cardiologists and respiratory physicians gave higher risk scores to conventional cigarettes and to electronic cigarettes, and marginally lower risk score (p = 0.049) to oral smoking cessation medications compared to all other healthcare professionals. They also gave a slightly higher risk score to inhaled smoke. Nicotine was ranked fourth among all smoking components listed by both groups. More than half of the participants of both groups considered the contribution of nicotine to smoking-related disease in general and to atherosclerosis as extremely or very important. The vast majority in both groups considered that nicotine replacement therapies were associated with lower health risk compared to smoking. Additionally, both groups overestimated the smoking cessation rates of nicotine replacement therapies and thought that nicotine in these products is synthetically produced rather than extracted from the tobacco plant. Fewer cardiologists and respiratory physicians compared to all other participants had recommended electronic cigarette use to smokers in the past and a lower proportion would recommend electronic cigarettes as smoking substitutes for smokers who are unable or unwilling to quit smoking with approved smoking cessation aids. A higher proportion of cardiologists and respiratory physicians compared to all other participants considered that electronic cigarettes were not effective in substituting smoking and proposed a ban on sales to youngsters, on use in public places and on advertising. More physicians than nurses suggested bans on electronic cigarettes use in public places as well as bans in advertising. Finally, more cardiologists and respiratory physicians said they knew the EU legislation on electronic cigarettes, although the rate of knowledge in both groups was very low.
3.5. Knowledge Score
To assess the knowledge about nicotine, nicotine replacement therapies and electronic cigarettes, a ”knowledge score“ was calculated for each participant. The correct answers to specific questions were scored with 1 point, while no point was given or deducted for wrong answers. Questions 12–20, 22–24, 27, 28 and 30 were used to generate the knowledge score (see Supplementary materials
The total knowledge score for all participants was 7.7 ± 2.4 points out of a maximum of 16 points. Males had higher knowledge score than women (8.3 ± 2.3 vs. 7.2 ± 2.3, p < 0.001). Furthermore, physicians had higher knowledge score than nurses (8.1 ± 2.4 vs. 6.8 ± 2.0 respectively, p < 0.001). Significant differences were found among participants depending on the profession and their specialty (one-way ANOVA p < 0.001). General practitioners (9.1 ± 1.9), respiratory physicians (8.6 ± 2.4) and pediatricians (8.5 ± 2.5) had higher knowledge scores, while nurses had the lowest score. No association was found between the knowledge score and the frequency of contact with smokers at work or the self-perceived level of knowledge about smoking. Also, there were no differences between smokers (current and former) and never smokers. A statistically significant but weak correlation between the knowledge score and working time was found (Pearson's r = 0.153, p = 0.013). In multivariate analysis (linear regression) high knowledge score was associated with male gender (β = 0.755, 95% CI = 0.153–6.041, p = 0.014) and general practitioners (β = 1.780, 95% CI = 0.533–3.008, p = 0.004), pediatricians (β = 1.415, 95% CI = 0.231–2.599, p = 0.019) and respiratory physicians (β = 1.379, 95% CI = 0.437–2.321, p = 0.004).
This study evaluated the knowledge and perceptions of healthcare professionals about nicotine, nicotine replacement therapies and electronic cigarettes. Participants had very frequent contact with smokers at work and felt they had high level of knowledge about smoking. However, an overestimation of the risks of nicotine was observed, with a significant proportion of participants considering that it has an extremely or very important contribution to the development of smoking-related diseases, including lung cancer and cancer in other organs, despite the fact that nicotine is not classified as a carcinogen. Additionally, a substantial proportion considered nicotine replacement therapies equally addictive to smoking. The negative perception about nicotine was evident from the fact that the majority would not recommend the long-term use of nicotine replacement therapies to smokers although guidelines from health organizations note that the risk from long-term use of nicotine is minimal and incomparable to continuous smoking [45
]. The knowledge about electronic cigarettes was rather poor, with many thinking that they involve combustion and that their operating temperature is higher compared to the combustion temperature of a tobacco cigarette. Few participants were aware of the pending EU legislation on electronic cigarettes. A significant proportion suggested that appropriate regulation should include banning nicotine and flavors in electronic cigarettes, although studies have shown that they contribute significantly to the smoking cessation effort [49
]. Many proposed that electronic cigarettes should be licensed as medications, despite the fact that they are not used as a therapeutic product by consumers [53
]. Finally, more than 40% would not recommend electronic cigarettes to smokers unable or unwilling to quit smoking by using approved medications, despite the fact that recently the American Heart Association suggested that the effort to quit smoking with the use of electronic cigarettes should be supported in this population of smokers [54
It was noteworthy that more than half of participants reported being current or former smokers. Smoking among healthcare professionals has been a long-standing issue. In fact, one of the first epidemiological studies highlighting the correlation between smoking and cancer was conducted in British physicians [55
]. In past decades, there were even cigarette advertisements from physicians [56
]. In the U.S., 40% of physicians smoked in 1959, with the rate falling to 21% in the 70s and 18% in the 80s [57
]. A meta-analysis of 81 studies examined the prevalence of smoking among healthcare professionals of various countries [60
]. The lowest smoking rates were observed in the U.S., UK and Australia while Greece had the highest rate with a smoking prevalence of 49%. Recently, a study of Greek nurses found that 32% of the participants were current and 14% were former smokers [61
], while another study found high prevalence of smoking and lack of formal training on cessation counseling among healthcare professions students [62
]. Herein, the smoking prevalence was similar to the above-mentioned studies. This is an important problem since healthcare professionals are role models for their patients and society, and the fact that they smoke compromises their potential to persuade their smoking patients to quit.
The differences in responses between smokers (current and former) and non-smokers were examined, assuming that personal experience with the smoking habit would differentiate their perceptions about nicotine and nicotine-containing products. Indeed we found that smokers gave a lower risk score to snus, while fewer supported the ban on the use of nicotine in electronic cigarettes compared with non-smokers. However, both groups overestimated the risk of nicotine and its contribution to smoking-related disease. Additionally, the two groups showed a similar deficit in their knowledge about electronic cigarettes.
Large differences in the responses between physicians and nurses were observed. The nurses felt less informed about smoking. As a result, they considered nicotine replacement therapies and oral medications more hazardous and the contribution of nicotine to smoking-related disease more important compared to physicians. Nurses had a lower knowledge score compared to physicians. Although some physician specialties (general practitioners, pediatricians and lung physicians) were associated with higher knowledge score than nurses, the score of knowledge was relatively low in the whole sample. Given that smoking prevalence is extremely high in Greece and counseling by nurses has been shown to increase the chance of quitting smoking [36
], the present study clearly demonstrates the need for the more thorough education of nurses, but also of physicians, about smoking in order to counsel smokers more effectively.
Significant knowledge gaps were observed in the study sample of cardiologists and respiratory physicians. These physicians treat the most prevalent smoking-related disease conditions and are also responsible for the smoking cessation clinics in Greece. Thus, they are probably considered by smokers as the most reliable source of information about smoking and smoking cessation. There is no doubt that it is preferable for smokers to quit without the use of any aid or with approved smoking cessation medications. However, the survey questions assessed the approach to a specific subpopulation of smokers: those who are unable or unwilling to quit with currently approved methods. These smokers will most likely maintain their smoking habit for a long time; thus, it is important that they receive reliable and unbiased information not only about electronic cigarettes but also about the long term use of nicotine replacement therapies, because these products could have an important role in significantly reducing their health risk.
Misconceptions about the relative risk of alternative nicotine-containing products compared to smoking have also been observed in the general public. Kiviniemi and Kozlowski recently reported that only 9% of a nationally representative sample of U.S. adults perceived smokeless tobacco products to be less harmful than smoking [63
]. One of the reasons for such perceptions is related to the “not safe” (in absolute terms) argument, which has been one of the central themes of tobacco control efforts and of various scientific organizations but has been criticized as poor-quality health information [64
]. Herein a significant proportion considered electronic cigarettes equally or even more harmful than smoking. This is expected, since there are scientific societies which have proposed to ban alternative to smoking products such as electronic cigarettes [65
], despite emerging evidence showing clinical benefit for smokers who switch to such products [66
]. The basis for such proposals has been the precautionary principle (based on the lack of long-term studies) which, however, seems to be applied erroneously [68
]. Additionally, there is a strong ideological opposition against the use of products containing nicotine [69
]. Thus, there are confusing reports about the benefits and risks of products such as electronic cigarettes [68
], which are likely influencing the perceptions of healthcare professionals. Moreover, participants were not aware of the pending EU legislation which, once implemented in May 2016, will create some quality standards through a proposed testing regime, will define limits on nicotine content and require consistent nicotine delivery, and will enforce the registration of all products available in the market. Thus, many healthcare professionals may think that electronic cigarettes will remain completely unregulated, creating uncertainty about their safety, quality and efficacy. Finally, there is a well-established lack of education especially at the undergraduate level in medical and nursing schools about smoking and smoking cessation [71
]. Potential improvements in healthcare professionals’ understanding about, and approach to, smoking alternatives are expected through better personal education (undergraduate and postgraduate) and through a reconsideration of the scientific community positioning towards tobacco harm reduction.
One of the limitations of the study is the applicability of the findings to all healthcare professionals in Greece and abroad. Obviously, the study recruited a convenient sample of healthcare professionals, so the findings should be interpreted with caution. However, the observations are not very different from similar surveys (mainly on physicians) evaluating perceptions for electronic cigarettes or other tobacco harm reduction products. Evidence from a study in Norway showed that healthcare professionals overestimate the adverse effects of another tobacco harm reduction product, snus [42
]. Another study among Swedish and British general practitioners found that participants had limited knowledge about nicotine in tobacco products and pharmaceutical nicotine [37
]. Finally, two recent studies found that only 30%–35% of surveyed physicians from the United States have recommended electronic cigarettes to smokers [73
]. Our findings are consistent with all these studies but present the views of a more generalized sample of healthcare professionals, including nurses and several physician specialties. However, future research recruiting a random sample of healthcare professionals would be valuable to further explore this issue. Another limitation of the study is the 30.3% response rate, which appears to be low. However, this is considered acceptable [75
] and comparable to other physician email surveys. Dykema et al.
had a response rate of 7.4% despite using a financial incentive for participation [77
]. Pepper et al.
evaluated the perceptions of physicians who treat adolescents about electronic cigarettes and had a response rate of 28% [78
], while Kandra et al.
performed a similar study among North Carolina physicians and had a response rate of 31% [74
]. General practitioners represented only 6.5% of the study sample. Although for most countries smokers are more likely to visit general practitioners for health-related issues, including smoking, the situation in Greece is different. Patients can visit specialist physicians in primary care on their own initiative (without the need to be referred by a general practitioner), and all medical specialties included in this study are available in primary care centers in Greece. Additionally, it is very common for specialists to have private offices and work as primary healthcare providers. Thus, the low proportion of general practitioners is not surprising. Finally, while a knowledge score was calculated, it does not cover all aspects of scientific information about nicotine and electronic cigarettes, it was a secondary objective of the study and was calculated to provide a rough generalized estimate of knowledge based on the specific questions of the survey. It is not proposed as a validated score to determine such knowledge in future studies.