Risk perception stands as a pivotal construct in numerous health behavior theories, representing an individual's thoughts and beliefs concerning the potential harms which could be caused by a particular behavior, such as smoking (28). This study was undertaken to assess the perceived risk of lung cancer and COPD among Iranian cigarette smokers. The findings of this study indicate that, overall, the subjects had a moderate level of perception regarding the risk of developing these two diseases due to their smoking habit. This aligns with the results of Oncken et al.'s study which was conducted in the United States, indicated a higher perceived risk of lung cancer compared to various smoking-related disease (e.g., cardiovascular and oral disease) risks among their subjects (29) which could be due to numerous population level educational programs in western countries to increase public awareness about role of smoking in causing lung cancer. In the broader context, researchers posit that a lower perceived risk towards health risk of smoking and tobacco products may contribute to increased initiation for non-smokers and decreased efforts to quit among smokers (30–32). On the other hand, a higher perceived risk could act as a preventive factor, deterring initiation in non-smokers or prompting cessation among smokers. These presumptions about the critical role of perceived risk are important in guiding the development of educational programs with the aim of reducing the burden of these disease among smokers and also for people who are in risk of becoming smokers (e.g., youth).
In finding of the study conducted by Zarghami et al., the average risk score for lung cancer was 12.97 out of 20, which was slightly higher than the present study (20). The collective evidence from various studies consistently underscores the tendency of smokers to underestimate their risk of developing diseases due to smoking (17, 18). For instance, a study with 2,785 participants from 12 North Carolina family practices revealed that smokers tend to underestimate their risk of COPD and lung cancer when compared to non-smokers and concludes that smokers may not understand the weight of health risks posed by smoking (19).
Regarding the age variable, the analysis revealed that the perceived risk of lung cancer increases by 0.12 points with each additional year of age among the subjects which means that older smokers have higher perceived risk compared to young participants. Similarly, for COPD, the perceived risk increases by 0.10 points per one year of increasing age when these findings align with prior research conducted by Hahn et al.(33), Ayanian and Cleary (18), and Romer and Jamieson (34) where these three studies also consistently demonstrate that older individuals tend to have a higher perceived risk of developing lung cancer compared to their younger counterparts. This reaffirms the consistency of the results observed in the present study.
Age at first use
The outcomes of the regression analysis revealed a significant difference in perceived risk for both lung cancer and COPD based on the age of smoking initiation. For instance, individuals who commenced smoking at the age of 20 or older exhibited a significantly lower perceived risk compared to those who started smoking before the age of 20 which could be interpreted as the longer is the duration of smoking, the higher is the perceived risk. Conversely, individuals who initiated smoking under the age of 20 had a higher perceived risk which could be due to their long duration of smoking at the time of conducting this study. In future studies this could be verified and tested by comparing participants who started smoking at age under 20 who had different duration of smoking at the time of study; eighter due to different ages or different combined years of smoking in their lifetime.
Overall, further investigation is warranted to delve into the factors contributing to this observed difference which helps to have comprehensive understanding of the underlying causes or other contributing factors.
Duration of smoking
Conversely, individuals with a smoking duration of 20 years or more, and particularly those with a smoking history exceeding 30 years, reported a significantly lower perceived risk compared to individuals with a smoking duration of less than ten years. In essence, as the duration of smoking increased in terms of years, the perceived risk among these individuals decreased which could justify why they have not been able to quit over these years. This finding is consistent with the results of Zarghami et al.'s study, where individuals who had smoked cigarettes for an extended period of time exhibited a lower perceived risk of lung cancer (20). However, it's noteworthy to mention that the results of a study by Chen et al. in America contradicted these findings, demonstrating an increase in the perceived risk of lung cancer with an extended duration of smoking (35). This inconsistency emphasizes the nuanced nature of factors influencing perceived risk which warrants further exploration. The observed difference in perceived risk between studies conducted in different countries may be attributed to the concerted efforts of media and information campaigns in America or other western societies. Because in the last decades non-profit organizations and the United States government have actively addressed the harms of smoking with the aim to increase awareness and understanding of the risks associated with smoking. In contrast, the societal focus on smoking and its dangers in our context might be comparatively lower which could be due to low socioeconomic or educational background of participants for this study or their lack of exposure to such campaigns or health educational programs.
In discussion on those who smoked for some years but don’t have any plans to quit yet, it must be noted that over time, when these individuals have not encountered specific clinical or immediate consequences of smoking, they may tend to underestimate or ignore the risk of smoking. This tendency could stem from a belief that, despite their prolonged duration of smoking, the absence of specific health issues might manifest as a lower risk of contracting diseases due to smoking (21). Conversely, existing research has consistently shown that the incidence of diseases such as lung cancer typically occurs in individuals aged 65 and older, with instances among those under 45 being a rare case (36). Consequently, the likelihood of developing lung cancer at the age of approximately 45 is considerably low. Therefore, it's crucial to note that the observed differences in the perceived risk in this study could be due to the lower average age in this study (35.57 ± 12.05 years), which is a relatively young age for developing lung cancer. In other words, participants of this study have lower risk of lung cancer because they are relatively younger and might not have developed any symptoms due to their smoking yet.
Number of consumed cigarettes
In addition to smoking duration, another influential variable in the perceived risk of developing diseases like lung cancer is the number of cigarettes consumed per day. The United States Preventive Services Task Force (USPSTF) identifies individuals aged 55 to 80 who have smoked 30 cigarettes per day as being at high risk of developing lung cancer (37). Accordingly, the USPSTF recommends screening for lung cancer among these group (37). It's also important to note that this study did not evaluate individuals' underlying diseases, such as heart conditions or oral cancer, where smoking is a significant risk factor.
Stage of Change,
One notable result from this study is the absence of a significant relationship between perceived risk and the stages of change among smokers which contradicts with previous research. For instance, Hahn et al. discovered that individuals in the preparation and contemplation stages of quitting smoking exhibited a heightened perceived risk of lung cancer and demonstrated a greater willingness to undergo lung cancer screening, compared to those in the pre-contemplation stage (33). The absence of a significant relationship between perceived risk and the stages of change in this study could be related to the lack of screening services for lung cancer in Iran.
Similarly, Ziebarth et al.'s study indicated that individuals who had no intention to quit smoking tended to perceive their risk of lung cancer as lower which could be in the line with the discussion above for those who have smoked for many years with low perceived risk (38). In the study conducted by Zarghami et al., individuals with an intention to quit smoking reported a higher level of perceived risk (20). These results are in contrast to the present study and underscore the complexity and variability in the relationship between perceived risk and the stages of change in smoking which needs further investigation.
Study limitations
While yielding significant results, this study is subject to certain limitations that should be considered when generalizing its findings. First, the cross-sectional nature of the study introduces inherent limitations commonly associated with this study design. Second, reliance on self-reporting of participants to the questionnaires introduces potential biases inherent in such methods. Third, the use of a questionnaire with a scoring range of 0–10, as opposed to alternative scales such as scales with the range of 0-100, may influence the precision of risk perception assessment. Finally, this study did not assess the potential underlying diseases of participants that might have impacted their perception of the risk. For instance, the study did not measure psychological and emotional factors, such as anxiety and depression, which could potentially influence the perception of risk among study subjects.