AIMS AND METHODS: The present study aimed to examine the changes in mean daily cigarette consumption among random samples of the Malaysian current smoker population over 20 years using an age-period-cohort (APC) approach. We conducted APC analysis using a multilevel hierarchical age-period-cohort model and data from four nationally representative, repeated cross-sectional surveys (National Health and Morbidity Survey) conducted in 1996, 2006, 2011, and 2015 among individuals aged 18 to 80 years. Analyses were also stratified by gender and ethnicity.
RESULTS: Overall, mean daily cigarette consumption (smoking intensity) among current smokers increased with age until 60, after which a drop was observed. There were increases in daily cigarette consumption across birth cohorts. Age and cohort trends did not vary by gender but by ethnicity. The decreasing cigarette consumption after age 60 among the current smoker population was consistent with those observed among the Chinese and Indians, a trend that was not observed in Malays and other aborigines. In contrast, the increasing cohort trend was consistent with those observed among the Malays and other bumiputras.
CONCLUSIONS: The present study highlighted important ethnic-specific trends for mean daily cigarette consumption among the current smoker population in Malaysia. These findings are essential in guiding the formulation of interventional strategies or implementation of national tobacco control policies and help achieve the Ministry of Health Malaysia's 2025 and 2045 targets for smoking prevalence.
IMPLICATIONS: This is the first APC study on smoking intensity among current smokers in a multiracial, middle-income nation. Very few studies had performed gender- and ethnic-stratified APC analyses. The ethnic-stratified APC analyses provide useful insights into the overall age and cohort trends observed among the current smoker population in Malaysia. Therefore, the present study could add evidence to the existing literature on the APC trends of smoking intensity. The APC trends are also important in guiding the government to develop, implement, and evaluate antismoking strategies.
METHODS: Data from four population-based National Health and Morbidity Surveys conducted in 1996, 2006, 2010, and 2015 were pooled. Hierarchical Age-Period-Cohort (HAPC) analysis explored the trajectories of BMI and waist circumference across the life course and birth cohorts by sex and ethnicity. These models assumed no period effect.
RESULTS: Generally, BMI and waist circumference trajectories increased across age and birth cohorts. These trajectories varied by sex and ethnicity. Females have more profound increasing BMI and waist circumference trajectories than their male counterparts as they age and as cohort recency increases. Chinese have less profound BMI and waist circumference increases across the life course and birth cohorts than other ethnic groups.
CONCLUSIONS: The profound increasing cohort trajectories of obesity, regardless of sex and ethnicity, are alarming. Future studies should focus on identifying factors associated with the less profound cohort effect among the Chinese to reduce the magnitude of trajectories in obesity, particularly among future generations.