Socioeconomic mental health disparities and income mobility in Australia: A longitudinal factor decomposition analysis

In recent years mental health disparity has been rising in Australia. The contributing factors to this rising disparity are not well understood. We investigated this by measuring and decomposing socioeconomic mental health inequality in Australia using the Household, Income and Labour Dynamics in Australia (HILDA) panel survey datasets between 2009 and 2017 employing the longitudinal factor decomposition method. In this research, we decompose the Income-Related Health Mobility (IRHM) and the Health-Related Income Mobility (HRIM) index. The IRHM index reflects the effect of the relationship between relative health changes at a constant income level, and the HRIM index represents changes in income ranking or income mobility with a fixed health outcome over time. Our findings suggest that poorer individuals cannot procure private health insurance, experience more long-term health conditions and have larger exposure to life shocks than richer individuals. Thus, long-term health conditions, private health insurance coverage, and number of life disruptions are the primary factors that negatively impact the IRHM index, thereby contributing to an increase in socioeconomic inequality in mental health in Australia. Moreover, the HRIM index exhibits a more pronounced adverse impact from labour force status compared to the relatively weaker positive effects observed in the IRHM index, resulting in a net negative effect from labour force status in this period. To address this, Australian governments should focus on implementing cost-effective intervention policies targeting disadvantaged populations to maximise health system resources and minimise mental health disparity by addressing the socioeconomic determinants of mental health.