Exposure to secondhand smoke among school-going adolescents in Malaysia: Results from the National Health and Morbidity Survey (NHMS) 2022: Adolescent Health Survey (AHS)

INTRODUCTION The adverse effects of secondhand smoke (SHS) exposure on health have been well established. Using the NHMS 2002: Adolescent Health Survey (AHS), this study attempts to evaluate the extent and factors associated with SHS exposure among Malaysian school-going adolescents. METHODS We conducted the NHMS 2022: AHS to gather a representative sample of school-age teenagers. We employed a cross-sectional study design and a multi-stage sampling procedure. We utilized a pre-validated self-administered questionnaire to collect data from the selected respondents. The data analysis included adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs). Additionally, we investigated the possible two-way interactions between the independent variables. RESULTS The SHS prevalence was 42.0%. Exposure to secondhand smoke (SHS) was associated with male gender (AOR=1.28; 95 CI: 1.20-1.38), older age (AOR=1.46; 95% CI: 1.33-1.60), Malay (AOR=1.88; 95% CI: 1.49-2.37), Bumiputra Sabah (AOR=2.23; 95% CI: 1.67-2.99), Bumiputra Sarawak (AOR=2.43; 95% CI: 1.80-3.28), and Chinese ethnicity (AOR=2.89; 95 CI: % 2.30-3.64), as well as current smoking (AOR=2.78; 95% CI: 2.50-3.09), having separated or divorced parents (AOR=1.12; 95% CI: 1.02-1.23), and parental tobacco product use (AOR=4.75; 95% CI: 4.44-5.08). We found significant interactions between: 1) Age group with gender and ethnicity; 2) Gender and ethnicity; and 3) Parental smoking status with gender, response to tobacco use, parents' marital status, and ethnicity. CONCLUSIONS Parental characteristics, sociodemographic characteristics, and SHS exposure are strongly correlated. In addition, there is evidence of smoking displacement to the house from other areas by parents/guardians. This study offers a fresh perspective on how these variables influence the likelihood of SHS exposure for Malaysian school-age teenagers. More efforts should focus on parental variables and sociodemographic traits, especially parental smoking cessation support.