An observational cross-sectional study was conducted by distributing an online survey to all individuals, both Saudi and non-Saudi, who are currently living in Riyadh city, using e-cigarettes, and aged above 18 years old. The minimum sample size needed for the study was determined to be 385 participants, based on an estimated sampling size at a 95% confidence level and a margin of error of 5%.

Data was collected between October 2022 and May 2023. Participants were excluded from the study if they did not live in Riyadh, were under 18 years old, or did not use e-cigarettes. The Institutional Review Board at Princess Nourah bint Abdulrahman University approved the study [HAP-01-R-059].

The self-reported questionnaire was distributed non-probably using convenience-sampling techniques to adults who use e-cigarettes in Riyadh through social media channels such as Twitter and WhatsApp, and their consent was obtained before participating in the study.

The structured questionnaire aims to examine the associations between e-cigarette use and psychological distress, as well as the perceived effects of electronic cigarette use on participation in activities of daily living (ADL) among Saudi adults in Riyadh. The first section of the questionnaire includes questions designed to assess sociodemographic characteristics, such as gender, age, academic level, chronic diseases, and employment status. This section is adapted from a previous study and is used with permission (4). The second section includes questions that evaluate the reasons, duration, amount, and status of using e-cigarettes, which are derived from a prior study with a similar goal to this one with permission (18). The third section, which is about perception on effects of electronic cigarette use on ADL, uses seven items, which include personal hygiene, financial management, health management, sleep quality, work performance, social participation, and participation in religious and spiritual activities, with responses ranging from strongly disagree = 1 to strongly agree = 5. A relevant score was created by summing up the individual coded items, and the overall score ranged between 7 and 35. Higher scores indicated perceived higher negative effects on ADL. Regarding psychological distress, data was collected using the Kessler 6 (K6) scale as a nonspecific mental health tool, which has six items measuring depression, hopelessness, everything was an effort, restlessness, nervousness, and worthlessness in the past 30 days (19). The responses were coded from 0 (none) to 4 (all). The psychological distress score was calculated by summing up these items, and the score ranged between 0 and 24. The validity of the questionnaire was assessed by five experts in the pulmonary medicine and rehabilitation field, who evaluated the questionnaire items on their linguistic, content, and relevance. They evaluated the questionnaire and suggested certain changes that the authors complied with. The experts verified the face and content validity of the questionnaire. The reliability was reached by pilot testing the questionnaire with 30 participants who matched the inclusion criteria, and they reported that the questionnaire was clear, understandable, and easy to answer. The internal consistency of the data was assessed, and a Cronbach’s coefficient alpha of 0.85 showed a high level of internal consistency.

Statistical analysis was carried out using R Studio (R version 4.1.1). Frequencies and percentages were used to present categorical data, whereas continuous data were expressed as the median and interquartile range (IQR). The internal consistency of perceived effects on ADL and the psychological distress assessment was checked using a Cronbach’s alpha test. To investigate the independent factors associated with the outcomes, two multivariate linear regression models were constructed. The first model had the negative ADL score as the dependent variable, and the following independent variables were entered: demographic characteristics (gender, age, educational level, monthly income, marital status, employment status, and chronic conditions), history of tobacco smoking, and patterns of e-cigarette use (the reasons for using e-cigarettes, current use of e-cigarettes, time at which the first e-cigarette was used, symptoms encountered during e-cigarette use, and family history of e-cigarette use). For the second model, the psychological distress score was the dependent variable, and the same independent variables were used as in the first model, plus ADL score. The results of the regression analysis were expressed as beta coefficients and their respective 95% confidence intervals (95% CIs).

Patterns of e-cigarette use were examined in the study. Less than half of the sample reported using e-cigarettes every day (45.7%). Additionally, 133 participants (33.6%) used e-cigarettes on some days, with 58.6% using e-cigarettes for one day and 41.4% using them for twenty days. The most common reasons for using e-cigarettes were to quit tobacco smoking (29.5%) and to use a safer way of smoking than tobacco cigarettes (16.2%). More than half of the respondents (56.3%) reported smoking their first e-cigarette within 30 minutes of waking up ( Table 2 ). The most frequently reported symptoms during e-cigarette use were cough (44.1%) and shortness of breath (42.3%), ( Figure 1 ). Additionally, 56.3% of the participants reported having a family member who smoked e-cigarettes. Roughly one-third of the respondents had never smoked a tobacco cigarette, while 23.7% and 23.2% were active every-day and some-day smokers, respectively ( Table 2 ).

The perceived effect of e-cigarettes use on activities of daily living was assessed using a questionnaire with a maximum score of 35. The median score (IQR) was 18.0 (12.8 to 23.0), with excellent internal consistency reliability (alpha = 0.898 based on 7 items). Health management activities such as physical fitness (44.5%), financial management (35.9%), and sleep quality (31.6%) were the most frequently reported negatively affected daily activities during e-cigarette use ( Figure 2A ).

The psychological distress of participants was evaluated using the K6 scale, which has a maximum score of 24. The median (IQR) K6 score was 11.0 (6.0 to 15.0), and the internal consistency reliability was excellent (alpha = 0.912 based on 6 items). Participants frequently reported feeling restless or fidgety (37.4%), that everything was an effort (33.4%), and being nervous (32.8%) ( Figure 2B ). Correlation analysis showed a significant positive correlation between the ADL and K6 scores (Spearman’s r = 0.364, p < 0.001, Figure 3 ).

The results of the multivariate regression analysis for predictors of perceived negative effects on activities of daily living and psychological distress are presented in detail in the = ( Supplementary Table S1 , S2 , respectively), and the significantly associated independent factors are summarized in Table 3 . The analysis revealed that perceived negative effects on activities of daily living were independently associated with having a history of COPD (beta = 0.35, 95% CI, 0.04 to 0.67, p = 0.029), experiencing cough (beta = 0.12, 95% CI, 0.02 to 0.22, p = 0.023), and shortness of breath (beta = 0.12, 95% CI, 0.01 to 0.23, p = 0.027) during e-cigarette use. Conversely, participants who perceived e-cigarettes as safer than tobacco cigarettes (beta = -0.17, 95% CI, -0.31 to -0.03, p = 0.021) and had other reasons for using e-cigarettes (beta = -0.18, 95% CI, -0.31 to -0.05, p = 0.006) were less likely to report negative effects on activities of daily living.

Regarding psychological distress, the multivariate regression model showed that participants aged 25 to 34 years (beta = -1.93, 95% CI, -3.72 to -0.15, p = 0.034) and 35 to 64 years (beta = -3.88, 95% CI, -6.82 to -0.95, p = 0.010) had lower psychological distress scores. Conversely, higher psychological distress scores were independently associated with being female (beta = 3.25, 95% CI, 1.81 to 4.69, p < 0.001), being widowed or divorced (beta = 4.52, 95% CI, 0.18 to 8.87, p = 0.041), having a history of arthritis (beta = 4.38, 95% CI, 0.50 to 8.25, p = 0.027), experiencing cough during e-cigarette use (beta = 1.55, 95% CI, 0.14 to 2.95, p = 0.031), and having higher scores of perceived negative effects on activities of daily living (beta = 0.26, 95% CI, 0.17 to 0.35, p < 0.001, Table 3 ).

A greater understanding of the characteristics of e-cigarette usage would enable more targeted preventive and treatment actions (20). In this study, smoking E-cigarettes was more prevalent among males aged 18 to 24 who had completed college or higher education. Similarly, a prior study conducted in Saudi Arabia in 2019 found that the majority of e-cigarette smokers were highly educated males aged around 18-24 (4). In this study, the most frequently reported reasons for using e-cigarettes in this study were quitting tobacco use and finding a safer alternative to traditional cigarettes. Consistent with previous research, health issues were identified as a common reason for initiating e-cigarettes use (21). It has been reported that tobacco smokers utilize electronic cigarettes to quit smoking traditional cigarettes, with e-cigarettes serving as a substitute (13). The findings of this study indicate that smoking e-cigarettes is associated with a perceived negative effect on respiratory health, as participants reported coughing, shortness of breath, and chest pain while using electronic cigarettes. Chaffee et al, reported a significant association between e-cigarette use and high rates of respiratory symptoms, including bronchitis and shortness of breath, among young people in the United States (22). This study revealed that e-cigarettes use is common among smokers with chronic illnesses such as asthma and hypertension, and around half of the participants had a family member who used e-cigarettes. A previous study found a higher prevalence of e-cigarette use among patients with comorbid disorders such as asthma and cardiovascular disease. As they believed that electronic cigarettes could aid them quit smoking, reduce combustible cigarette consumption, and mitigate the adverse effects of smoking (23). A recent study also found that individuals with smokers in their families are more likely to become smokers than those without smokers in their families (24). Therefore, it can be inferred that people are influenced by their family members and mimic their smoking practices. These results highlight the necessity of involving peers and family in interventions, as they play a significant role in shaping attitudes and behaviors related to e-cigarette use.

The findings of this study revealed a median K6 score of 11, indicating a high level of psychological stress among adult e-cigarette users. Several studies have investigated the association between e-cigarette use and psychological distress. Some studies indicate that e-cigarette use increases psychological distress, while others indicate that those who are already experiencing psychological distress are more likely to turn to e-cigarettes as a coping method. A previous study found that former smokers with a high level of psychological distress are more likely to use e-cigarettes (25). Another study reported that individuals with symptoms of anxiety and depression are at high risk of becoming e-cigarette users (26). Additionally, a different study demonstrated that adolescents who use electronic cigarettes exhibit a moderate level of emotional disorders, which is lower than combustible cigarette users but higher than non-smokers (25). Furthermore, a scoping review published in 2022, illustrated that the prevalence of e-cigarettes is increasing among adolescents between 10-21 years old, and their mental health is negatively affected while smoking electronic cigarettes (27). Consistent with previous studies, the majority of the individuals in this study reported feeling anxious, restless, and stressed out about everything. In addition, this study found a strong correlation between being female and experiencing severe psychological distress. This finding is supported by previous studies that reported that female e-cigarette users are more likely to experience negative effects on their mental health (27–29). Moreover, another study found that female adolescents who use e-cigarettes face higher risk of developing mental issues such as suicidal ideation and depression compared to males (27).

Smoking increased the likelihood of experiencing difficulties in activities of daily living (ADL), regardless of cognitive functioning. However, it had a more negative impact on individuals who were already at a higher risk of cognitive impairment (30). A long-term follow-up study found that middle-aged smokers had a twice-as-higher risk of future impaired ADL compared to nonsmokers (31). Regarding the perceived detrimental effect associated with e-cigarette use on activities of daily living, several areas of daily living activity were affected, with the majority of study participants reporting a negative impact on their sleep quality. This is consistent with previous research findings that found a link between poor sleep quality and high e-cigarette use (32), as well as reports that most e-cigarette users e experience more sleep problems than non-smokers (33), and participants who used e-cigarettes had significantly shorter sleep durations (34). Financial management was another area affected by e-cigarette use, with participants reporting difficulties in managing their finances. This finding aligns with previous studies that have highlighted the financial burden associated with e-cigarette use which is more cost-effective than utilizing nicotine replacement medication (35). Health management was also negatively impacted in numerous areas, including physical fitness, as the participants reported In contrast, another study found that e-cigarette users are more likely to be physical activists when compared to cigarette smokers (17). Another study finding indicates that individuals who engage in fewer activities of daily living (ADLs), such as physical fitness, and have poor sleep quality, have a greater influence on their mental health. The study finding aligns with another study that found daily activities (ADL) may play a significant role in the link between poor sleep and mental stress. However, ADL only partially explains the relationship between poor sleep and psychological distress (36). The multivariate regression analysis for predictors of perceived negative effects of e-cigarette use on activities of daily living revealed that having a history of chronic obstructive pulmonary disease (COPD) and experiencing cough and shortness of breath were independently associated with lower ADL scores. Previous research data on the short-term impacts of e-cigarette usage shows that the vapor generated and inhaled by e-cigarette users has an adverse effect on airways and lung health of young people (37, 38). This may, therefore, impact their level of engagement in daily activities.

The results of this study contribute to the existing literature on the factors associated with e-cigarette use and its potential negative impacts on both physical and mental health. These findings have important implications for the development of health education interventions and effective smoking prevention policies in Saudi Arabia. Furthermore, the study highlights the need to raise awareness about the negative impact associated with e-cigarette use on the mental health of adults and their ability to participate in meaningful life activities.