Association of excise duty reforms with alcohol per capita consumption and alcohol-attributable life expectancy loss in Malaysia, 2000–2022: An interrupted time-series analysis

Background Malaysia is a predominantly Muslim, upper-middle-income country where approximately 10% of the population consumes alcohol, yet heavy episodic drinking is common among drinkers. Despite multiple excise duty reforms between 2000 and 2022, their population-level impact on alcohol consumption and alcohol-attributable harm remains unclear. This study evaluates the effects of three major excise duty changes on adult alcohol per capita consumption (APC) and estimates alcohol-attributable life expectancy loss over time. Methods A longitudinal ecological design was applied using annual national data (2000–2022) from WHO World Health Statistics 2025. Alcohol-attributable life expectancy loss was estimated by comparing observed WHO Global Health Observatory life tables with a counterfactual scenario of lifetime abstinence, using mortality fractions from a comparative risk assessment based on IHME Global Burden of Disease data. Interrupted time-series analysis with generalised least squares regression assessed the impact of excise duty reforms in 2004, 2012, and 2016 on APC. Results Between 2000 and 2022, gross domestic product per capita at purchasing power parity (GDP-PPP) and life expectancy increased, while alcohol-attributable life expectancy loss averaged 0.30 years. Life expectancy losses were negatively correlated with life expectancy (ρ = –0.626; 95% CI: –0.829 to –0.278) and APC (ρ = –0.557; 95% CI: –0.793 to –0.178). Following the 2004 tax increase, APC temporarily rose above projected levels before resuming a declining trajectory from 2006. The 2012 Excise Duties Order produced a significant immediate reduction in APC, sustained for two years. In contrast, the 2016 Amendment was associated with a significant rise in APC (β = 0.060, p < 0.001), with consumption exceeding the underlying upward trend. Conclusion Excise duty policies can produce short-term reductions in alcohol consumption but are insufficient to sustain long-term declines.