Background/Purpose : The relationship between poverty and SLE damage has been observed in several cross-sectional studies. The aim of the present study was to use longitudinal data to examine the effects of poverty status, dose of poverty, and exiting poverty on subsequent disease damage.

Methods: Data are from the UCSF Lupus Outcomes Study. Study participants were recruited from diverse sources in 2003 and followed through 2015 through annual structured surveys. SLE diagnoses were confirmed by medical record review.  In each year we characterized the respondents’ poverty status in the surveys based on household income and family size.  Beginning in 2009, the survey included a validated measure of disease damage, the Brief Index of Lupus Damage.  We used ordinary least squares regression to estimate the impact of 1) poverty in 2009, 2) the dose of poverty defined as the percentage of years in poverty between 2003 and 2009, and 3) the effect of permanently leaving poverty by 2009 on change in damage between 2009 and 2015, with and without adjustment for potential confounding variables (demographics, education, SLE duration, characteristics of health care, and health behaviors).  To account for attrition and missing variables, multiple imputation was used.

Results: In 2009, there were 783 respondents to the Lupus Outcomes Study annual survey, of whom 94% were female, 35% non-white, and 15% were in poverty. They were 49.8(SD12.3) years of age and had had SLE for 16.9(SD8.3) years. Damage scores averaged 1.9(SD2.0, range 0-12). Table 1 shows the effect of poverty in 2009, dose of poverty between 2003 and 2009, and exiting poverty permanently by 2009 on change in damage, with and without adjustment. Those in poverty had greater increases in damage as did those continuously poor vs. poor some years vs. never poor.  Exiting poverty was associated with change in damage scores closer to that among those who were never poor with the passage of as little as a year and smaller than those who remained poor. In all analyses, adjustment had minimal effect on results, indicating that the effect of confounding variables was minimal.  

Conclusion: Persons with SLE who were poor in all years experience greater accrual of damage than those who were poor only some years and those who were never poor, but exiting poverty is associated with a decreased accrual of damage. Income support policies may be critical to reducing damage in SLE.