Racial and Socioeconomic Differences in Chronic Low Back Pain

Project Summary/Abstract Low back pain is one of the most common disabling conditions in the world. The worldwide point prevalence of activity-limiting (acute and chronic) low back pain is approximately 12%, which equates to approximately 933 million people globally suffering with low back pain at any given time. Chronic low back pain (cLBP) refers to pain lasting at least twelve weeks or longer, and it is consistently among the top five most common reasons for primary care physician visits. Although some individuals with cLBP have clear pathoanatomic causes of pain, the vast majority of cLBP is “non-specific” and is not accompanied by readily identifiable pathology of the spine or related tissues. Without a clear target for treatment of cLBP, effective pain management can be difficult to achieve. Because objective measures of disease activity have not consistently been strong predictors of clinical symptoms, cLBP provides an excellent model for investigating the influence of social determinants such as racial background and social stress on the progression of pain and disability over time. During our previous funding cycle, we found evidence that non-Hispanic Black (NHB) individuals with cLBP reported significantly greater pain severity and disability than their non-Hispanic White (NHW) counterparts. In addition, we observed racial differences in pain-related psychosocial and biological measures, which were significantly associated with racial group disparities in cLBP severity. Furthermore, racial disparities in cLBP were exacerbated by low socioeconomic status (SES), such that NHBs with low SES demonstrated the absolute greatest burden of cLBP. While our findings demonstrate clear racial differences in cLBP severity and disability between NHBs and NHWs, the findings are largely indirect and cross-sectional. Differences in how cLBP progresses over time between NHBs and NHWs, as well as factors that contribute to cLBP progression, remain poorly understood. Among the multiple factors that inevitably contribute to racial group differences in cLBP, social stress represents a potentially important social determinant of greater cLBP severity and disability in NHBs. For this proposed follow-up study, we will elucidate the contribution of social stress and its biological consequences (i.e., allostatic load) to racial group disparities in cLBP by prospectively assessing the two-year progression of clinical pain and disability, as well as pain-relevant psychosocial functioning among NHBs and NHWs with cLBP. We will use minority stress theory to guide the study aims related to the progression of racial group disparities in cLBP; however, we will also use a recently developed resilience framework to guide inclusion of psychosocial resilience factors that may mitigate the effects of social stress on cLBP in NHBs and/or NHWs.