Purpose: This study was conducted to investigate the association between low income and substance use disorders (SUDs), Methods: Data were collected from the National Health Insurance Research Database (NHIRD). A total of 1,824,491 people were followed from 2001 to 2010. Cox proportional hazards regression models were used for analysis. Results: The incidence rates of SUD were higher in low-income than in non-low-income earners. The hazard ratios (HRs) and 95% confidence intervals (CIs) for SUD were 1.535 (1.316-1.791) and 1.812 (1.420-2.313) in low-income men and 2.706 (2.228-3.287) and 3.512 (2.221-5.553) in women in the 18-44 and 45-64 age groups, respectively. The HRs for SUD were higher in low-income females than in low-income males. Conclusion: Low income is a risk factor for SUD in both men and women. The incidence of substance use is higher in low-income men than in low-income women, whereas HRs are higher in women than in men aged 18-64 years.
