This study aimed at investigating the effect of factors related to HL based on the constructs of HBM about smoking prevention among students. The results of this study indicated that the three constructs of HBM had significant effects on HL. The study findings were consistent with the hypotheses of the researchers, which included the potential effects of HL on constructs of HBM (
16), as well as the various roles of HL among the constructs of HBM, such as creating perfect knowledge and enough perceived susceptibility; the relationship between education and perceived severity, perceived benefits, and perceived barriers; the relationship between self-efficacy and behavior change; the role of media as a cue to action; and the role patient education can play in building HL (
15).
The results showed that perceived susceptibility was the strongest predictor of HL. Regarding the possible causes of this effect, it can be said that perceived susceptibility has a strong cognitive component and is somewhat dependent on individual knowledge (
21), and the same type with HL. On the other hand, one of the important roles of HL in the HBM is to create enough perceived susceptibility (
15). Therefore, it can be concluded that perceived susceptibility can influence the variables of the type itself, such as HL.
The results showed that perceived benefits had a significant effect on HL. Regarding this effect, it can be said that due to the role of HL in helping the HBM to design training programs tailored for perceived benefits of the audience (
15), this effect is justifiable.
In this study, self-efficacy had a significant effect on HL. Regarding the possible causes of this effect, it can be said that self-efficacy is one of the main dimensions of HL (
22), and HL also plays a role in the relationship between self-efficacy and adoption of behavior (
15). Furthermore, there is a relationship between HL and self-efficacy (
23,
24). Therefore, self-efficacy can influence HL.
The results showed that there was a significant and direct correlation between HL and all the constructs of HBM. Considering the various roles of HL among the constructs of the HBM (
15), this findings imply that the sum of these constructs can help create the skills and abilities necessary for a desirable level of HL.
The results showed that perceived susceptibility and self-efficacy constructs had the highest correlation with HL. Given the important role of HL in creating enough perceived susceptibility (
15) and the relationship between HL and self-efficacy (
23,
24), these results are justifiable.
The results of the present study indicated that the HL in the students was moderate, and the level of HL in more than one-third of the participating students was inadequate and problematic. The results of this study were in contrast with the results of the study by Ramezankhani et al. (
10), in which the HL of more than two-thirds of the students was marginal and inadequate. Among the possible reasons for this discrepancy are the higher number of women than men, the education of different medical sciences and the easier questions of the HELIA questionnaire compared to the Newest Vital Sign (NVS), in this study compared to the study by Ramezankhani et al. The results of the present study were not consistent with the results of the study done by Zhang and Cui (
25), which reported low levels of HL among students. These conflicting results are due the sample of this study, which comprised of students from different disciplines of non-medical sciences, whereas the samples of the present study were from various medical sciences students. Also, the results of the study by Vozikis et al. (
9), in which the level of HL was moderate to high, seems to be consistent with the results of this study; despite the difference between the above study and the present study, in terms of topics, such as the presence of students studied at higher educational levels and also the HL tool (Bostock Query Questionnaire), they had similar results with the present study.
The results of the present study reflected that among independent variables, perceived benefits and self-efficacy received the highest scores, while perceived susceptibility and perceived barriers had the lowest scores. These results were consistent with the results of the study by Li and Kay (
11) and Reisi et al. (
13). In justifying the results of this section, the following points can be made: The high score obtained from the perceived benefits variable may be related to the study of students in medical sciences and their adequate knowledge of the benefits of adoption of smoking preventive behaviors. Regarding the perceived barriers variable, it is possible to say that some of the items used to measure perceived barriers in this study, were probably not considered to be barriers to adoption of smoking preventive behaviors. For this reason, students have scored lower grades. Moreover, a higher score in perceived benefits is associated with reduction in perceived barriers score (
21). On the other hand, perceived barriers and self-efficacy are related, so that if perceived barriers are low, self-efficacy increases regarding preventive behaviors (
21). Therefore, due to the low score of perceived barriers in this study, self-efficacy score was high. Regarding the low level of perceived susceptibility, it can be inferred that given the participants in this study were a group of young people, they did not know the likely risk of illnesses caused by smoking or exposure to smoke.
The results showed that there was a significant relationship between HL and smoking status so that the prevalence of inadequate and problematic HL in smokers was higher in comparison with non-smokers. These findings were consistent with the findings of the study by Hoover et al. (
5), Stewart et al. (
6), Stewart et al. (
7), and Fernandez et al. (
8). According to the findings, it can be said that low HL is a specific conceptual interpretation of inadequate Awareness regarding the harmful impacts of smoking on health. Furthermore, it is related to an inappropriate attitude towards smoking. Thus, low HL can lead to smoking.
In the present study, there was a significant relationship between gender and HL, so that the prevalence of inadequate and problematic HL in males was higher in comparison with females and the prevalence of adequate and excellent HL was higher in females than males. These results were not consistent with the results of most studies (
26,
27). Possible reasons for the higher level of HL of female students include greater respect for health standards, more medical recommendations, such as periodic examinations, and greater female’s interest in learning and obtaining health information. In this case, the results of the present study were consistent with the results of Zhang and Cui (
25) and Shah et al. (
28), and there was a significant difference between the HL level of females and males.
5.1. Limitations of the Study
The limitations of this study include the lack of specific questionnaire for measuring HL regarding smoking. One of most important limitations of this study was the failure of path analysis to predict HL by the constructs of HBM, such as the coexistence between some of the constructs of HBM and HL dimensions and the uniformity of the two questionnaires. The other limitation of the study was that the target group that included undergraduate dormitory students. Thus, the results of current study cannot be generalized to other students and other age groups. Therefore, the study is recommended to be conducted on different groups and populations. Furthermore, participants in the current study were undergraduates of different medical sciences, which are a group with higher HL than common people and this item may have an effect on the results of the study. Another limitation of this study was that the data collection, which was self-reported.
5.2. Conclusions
In conclusion, regarding the relationship between HL and smoking, and considering that perceived susceptibility, perceived benefits and self-efficacy variables were predictors of HL and had a high correlation with HL, it could be suggested that educational programs are based on the HBM with emphasis on the above three constructs, and can be used as a suitable framework for designing and implementing interventions to improve HL and smoking prevention. Eventually, it should be noted that despite the relationship between HL and some constructs of HBM, more studies are still required to determine, which construct is more related to HL.