INTRODUCTION

Electronic cigarettes (e-cigarettes), also known as ‘e-cigs’ and ‘vapes’, have become a new threat to public health since their introduction into the market in the past two decades¹. E-cigarettes are battery-powered devices that allow users to inhale nicotine into the lungs through vapor². Besides nicotine, e-cigarette aerosol can also contain other substances such as cancer-causing chemicals, volatile organic compounds, and heavy metals that can harm health^3,4.

As e-cigarette use is relatively new in the population, the long-term effects of its use are still being studied, though growing evidence suggests several potential health risks^5,6. Prolonged nicotine exposure can lead to addiction, and studies have also raised concerns about the potential for e-cigarettes to act as a gateway to traditional cigarette smoking, particularly among adolescents⁷. Research also indicates that long-term e-cigarette use may contribute to cardiovascular diseases by damaging blood vessels and promoting inflammation⁶. Chronic exposure to e-cigarette aerosol has been linked to measurable airway inflammation and biological alterations in human lung tissue, including increases in inflammatory markers⁸.

The use of e-cigarettes, especially among adolescents, has risen substantially in recent years^2,9. In Malaysia, the first national survey conducted in 2016 reported that 9.1% of adolescents aged 10–19 years were current e-cigarette users¹⁰. Evidence from previous reviews indicates that individual factors such as older age, male sex, and concurrent use of conventional cigarettes are associated with a higher likelihood of e-cigarette use among adolescents¹¹. Besides individual determinants, peer influence¹¹ and parental factors such as parental use of tobacco or nicotine products, have also been consistently linked to adolescent e-cigarette uptake¹². Monitoring the prevalence and trends of e-cigarette use is therefore critical for informing public health strategies aimed at preventing nicotine addiction among young people. This study examines changes in the prevalence of e-cigarette use among adolescents in Malaysia across three national surveys conducted between 2016 and 2022.

METHODS

This study is a secondary analysis of three nationally representative school-based surveys conducted among adolescents in Malaysia: Tobacco and E-cigarette Survey among Malaysian Adolescents (TECMA) 2016, National Health and Morbidity Survey (NHMS) 2017, and NHMS 2022. The NHMS 2017 and NHMS 2022 had a similar target population, which consisted of adolescents aged 13–17 years (Forms 1–5, corresponding to lower and upper secondary school levels), while the target population for TECMA was adolescents aged 10–19 years. In studying the trend, data on adolescents aged 13–17 years were extracted from the TECMA 2016 dataset and reanalyzed to make it comparable to the NHMS data.

The surveys used a two-stage stratified cluster sampling design to select a representative sample of school-going adolescents in Malaysia. Stratification was according to the states in Malaysia. Two-stage sampling was performed within each state, with schools as the primary sampling unit (PSU) and classes within the selected schools as the secondary sampling unit (SSU). Schools from each stratum were randomly selected via a probability-proportionate-to-size (PPS) method, and classes were randomly selected from each selected school. All students from the selected classes were included in the survey.

Ethical approval was obtained from the Medical Research and Ethics Committee (MREC), Ministry of Health Malaysia [TECMA 2016 (NMRR-16-108-28789), NHMS 2017 (NMRR-16-698-30042), NHMS 2022 (NMRR-21-157-58261)]. Informed consent was obtained from all subjects and, for subjects under 18 years, from a parent and/or legal guardian. All methods were carried out in accordance with relevant guidelines and regulations.

RESULTS

A total of 13162, 27497, and 33523 respondents participated in TECMA 2016, NHMS 2017, and NHMS 2022, with response rates of 88.7%, 89.2%, and 89.4%, respectively. Out of 13162 respondents, 8924 data of individuals aged 13–17 years were extracted from TECMA 2016 for this study. Table 1 shows the sociodemographic characteristics of the respondents from each survey in this study.

The surveys showed that 12.0%, 9.8%, and 14.9% of adolescents aged 13–17 years were current e-cigarette users in 2016, 2017, and 2022, respectively, corresponding to approximately 238000, 211000, and 307000 adolescents nationwide based on weighted population estimates. The prevalence of e-cigarette users was consistently higher in males (15.5–23.5%) compared to females (2.8–6.2%), rural dwellers (11.2–20.8%) compared to urban dwellers (8.8–13.5%), and increased with age in all three surveys (Table 2).

Multivariable logistic regression analysis of NHMS 2017 and NHMS 2022 data revealed that, after controlling for gender, age, ethnicity, parents’ smoking status, and parents’ e-cigarette use, the adjusted odds ratio (AOR) of e-cigarette use showed a substantial increase from 2017 to 2022 among adolescents who smoke (from 15.25 to 56.29) and among Malays (from 1.78 to 3.71) and the ‘other ethnicities’ (from 2.05 to 3.83). The AOR also increased with age (school form) and among students whose parents smoke. However, the association between adolescents’ e-cigarette use and their parents’ e-cigarette use decreased, with the AOR decreasing from 3.78 to 1.64 (Table 3).

DISCUSSION

This study describes changes in the prevalence of e-cigarette use among adolescents across three national school-based health surveys conducted between 2016 and 2022, conducted in Malaysia. Although the prevalence fluctuated over the years, there was an overall increase during this period, with higher rates observed across all sociodemographic groups in 2022 compared to the earlier surveys in 2016 and 2017. This rising trend is concerning, as e-cigarette use may expose adolescents to nicotine, potentially leading to addiction and increasing the likelihood of cigarette smoking initiation among non-smokers^14,15. The prevalence of e-cigarette use also increased in the US from 0.6% in 2011 to 4.9% in 2018 among middle school students and from 1.5% to 20.8% among high school students¹⁶. Based on the Global Youth Tobacco Survey from 2012 to 2020, 7 of 10 countries with 2 waves of data showed a significant increase in the adjusted prevalence of e-cigarette use, i.e. Georgia (from 5.7% to 12.2%), Italy (from 7.8% to 17.3%), Latvia (from 9.7% to 18.3), Albania (from 5.5% to 9.2%), Nicaragua (from 5.2% to 8.5%), Paraguay (from 3.6% to 12.5%), and Peru (from 2.2% to 6.6%)¹⁷. However, the adjusted prevalence of e-cigarette use had decreased in Iraq from 10.8% to 7.1%¹⁷. This overall increasing trend could be attributed to several factors, including aggressive and appealing characteristics of e-cigarette marketing targeting young people^18,19, perceptions that e-cigarettes are less harmful than traditional cigarettes^18,20, along with social influences and curiosity^19,21.

Alarmingly, the prevalence of e-cigarette use among adolescents in Malaysia was higher than the global average of 9.2%²² and ranked among the highest in Asian countries²¹. Other countries that reported high adolescent e-cigarette use included Canada, with a national average of 31.4%²³, Poland 17.1%²³, Italy 17.5%¹⁶, Latvia 18.0%¹⁶, and United Kingdom 13.3%²³. In Southeast Asia, the Philippines and Indonesia also reported high prevalence rates of current e-cigarette use, at 14.1%²¹ and 11.8%, respectively²⁴. The increase in e-cigarette use observed in 2022 should also be interpreted in the context of Malaysia’s regulatory environment during the study period. Prior to recent legislative efforts, e-cigarettes were subject to relatively limited regulation, which may have contributed to increased availability, marketing exposure, and uptake among adolescents.

In this study, among adolescents in Malaysia, being a current smoker is a very strong determinant of ecigarette use: the NHMS 2022 found an AOR of 56.29 for ecigarette use among adolescents who smoke. This represents a significant increase compared to NHMS 2017, where an AOR of 15.25 for current smokers versus non-smokers was reported. The extremely high adjusted odds ratio observed among current cigarette smokers likely reflects strong clustering of nicotine-use behaviors among adolescents in 2022. Youth who already smoke cigarettes may be more willing to experiment with alternative nicotine products such as e-cigarettes. In addition, overlapping behavioral and social risk factors may contribute to concurrent use of multiple nicotine products among adolescents. The large magnitude of the association should be interpreted cautiously, as cigarette smoking and e-cigarette use represent closely related nicotine-use behaviors and may occur concurrently among adolescents^25,26. Comparatively, in other Southeast Asian countries and more broadly, smoking status is also a strong correlate of ecigarette use, though the odds tend to be lower than Malaysia’s latest estimate. In Thailand, a study of seventhgrade students found that current cigarette smoking was associated with current ecigarette use, with an AOR of about 4.28²⁷. Globally, the 2012–2019 Global Youth Tobacco Survey data show that youth who smoke cigarettes had an AOR of about 7.18 for ecigarette use compared to nonsmokers²².

In Malaysia, consistent with the pattern observed for conventional cigarette smoking, the trend of e-cigarette use among adolescents demonstrated pronounced sex-related differences^28,29. Since the first national survey on e-cigarettes (TECMA 2016), the prevalence has remained substantially higher among males, reaching approximately 23.5% in 2022. Although the prevalence among females remained lower than that of males, it increased to 6.2% in 2022, representing a twofold rise from the baseline of 3.1% in 2016. This disparity is further supported by findings from multivariable analyses, which showed that the AOR of e-cigarette use was approximately four times higher among males than females. These findings align with global evidence in nearly all countries, where males exhibit a higher prevalence of e-cigarette use than females. In a systematic review of e-cigarette use among adolescents in Southeast Asia, seven out of ten studies identified male gender as a significant risk factor for e-cigarette use among adolescents³⁰. Similarly, a multi-country analysis across 68 nations reported that among youth aged 12–16 years, the prevalence of e-cigarette use averaged 11.7% for males compared to 6.6% for females²². In this context, the 2022 prevalence of e-cigarette use among Malaysian male adolescents (23.5%) placed the country at the higher end of global estimates, while the corresponding rate among females (6.2%) remained comparatively moderate. Nonetheless, the doubling in prevalence among females highlights a concerning upward trend and a gradual narrowing of the sex gap in adolescent e-cigarette use in Malaysia.

Age-related differences in e-cigarette use among adolescents in Malaysia reveal a consistent pattern, whereby older adolescents are more likely to use e-cigarettes than their younger counterparts. From 2016 to 2022, although the prevalence did not increase markedly within specific age groups, the overall pattern indicated an upward trend in e-cigarette use with increasing age. This pattern is further supported by logistic regression analyses, which demonstrated a strengthening association between age and e-cigarette use from 2017 to 2022. A similar age gradient has been observed globally. In the United States, for example, a study among youths aged 13–18 years reported that the prevalence of current e-cigarette use peaked in the age group 16–18 years, approximately 30% in 2019, and remained consistently higher among older adolescents compared to younger ones³¹. Likewise, a global study involving 68 countries found that older youths (12–16 years) were significantly more likely to use e-cigarettes than their younger peers²². Malaysia’s pattern, wherein older adolescents demonstrate higher prevalence and risk of e-cigarette use, therefore aligns with international findings. These observations underscore the importance of designing prevention and intervention strategies that target not only early adolescents but also focus on mid- to late-adolescent groups, where initiation and uptake are more likely to occur.

This study shows that parental smoking status was associated with adolescents’ e-cigarette use in the NHMS 2022, although this association was not observed in the earlier 2017 survey. A similar pattern was also identified for parental e-cigarette use. Globally, adolescents with parents or family members who smoke, consistently show a significantly higher risk of e-cigarette use, a relationship supported by evidence across multiple regions. A meta-analysis of 21 studies found that having any family member who smokes increased the odds of adolescent e-cigarette use (OR=1.47), while the odds associated specifically with parental smoking were 1.41. In Southeast Asia, a systematic review similarly concluded that parental influence, including parental smoking, is a key socio-ecological factor associated with higher e-cigarette use among adolescents³⁰, indicating that this parental effect persists across diverse cultural settings. Parental smoking or e-cigarette use may contribute to adolescent uptake by normalizing nicotine use within the household, lowering adolescents’ perceived harm, and increasing access to nicotine products.

In this trend analysis, Malaysia consistently demonstrates ethnic disparities in adolescent e-cigarette use, with Malays and the ‘other ethnicities’ exhibiting higher prevalence, a pattern that persists across TECMA and NHMS survey waves amid an overall rise in national prevalence. These persistent ethnic differences suggest that population-level prevention strategies alone may be insufficient. Targeted interventions that are culturally appropriate and context-specific, particularly for Malay adolescents, may be necessary to address the higher uptake of e-cigarettes observed in this group.

CONCLUSIONS

The prevalence of e-cigarette use among adolescents has substantially increased over the last decade in Malaysia. Although the patterns of associated sociodemographic factors remain generally consistent, the strength of these associations has changed for some factors over the study periods. These findings highlight the need for continued public health efforts and appropriate regulatory strategies to address e-cigarette use among adolescents in Malaysia.