Low Income and Nonwhite Race are Strongly Associated with Worse Quality of Life in Patients with Nephrolithiasis.

Kidney stones are a source of significant morbidity which have been shown to negatively impact health related quality of life. We sought to understand the association between health related quality of life, socioeconomic status and race among patients with kidney stones. Patients with stones at a total of 11 stone centers across the United States completed the WISQOL (Wisconsin Stone Quality of Life questionnaire). The patient ZIP Code™ was used to estimate household income. A mixed effects regression model was constructed for analysis with ZIP Code as the random intercept. A total of 2,057 stone formers completed the WISQOL. Lower income was independently associated with significantly lower health related quality of life (β = 0.372, p = 0.014), as were nonwhite race (β = -0.299, p = 0.001), unemployed work status (β = -0.291, p = 0.008), female gender (β = -0.204, p <0.001), body mass index greater than 40 kg/m Lower income, nonwhite race and unemployed work status were independently associated with lower health related quality of life among patients with kidney stones. While clinical characteristics such as body mass and stone disease severity were also associated with health related quality of life, this study shows that socioeconomic factors are similarly important. Further research to understand the specific mechanisms by which socioeconomic status and race impact health may lend insight into methods to optimize clinical treatment of stone formers and patients with other chronic diseases.