Chronic low back pain (cLBP) is the leading cause of disability, with a significant societal cost. It disproportionately affects non-Hispanic blacks and individuals of lower socioeconomic status. The biopsychosocial framework has been used to study and manage cLBP, yet disparities persist.
The objective of this study was to assess whether self-identified race moderated the relationship between perceived social status and cLBP outcomes (pain interference and pain severity) and investigate whether race moderated the indirect relationship between perceived social status and pain outcomes via depressive symptoms.
Fifty-seven blacks and 48 whites with cLBP were recruited as part of a large ongoing study. Depressive symptoms, objective and subjective measures of socioeconomic status, and pain outcomes were measured. Hayes’ moderated mediation model was used to estimate conditional direct and indirect relationship between these variables.
On average black participants reported significantly more pain interference (4.12 [SD=2.65] vs. 2.95 [SD=2.13]) and severity (5.57 [SD=2.27] vs. 3.99 [SD=1.99]) than white participants, (P<0.05). Race moderated the association between perceived social status and pain interference: higher social status decreases pain interference for white participants, but that trend was not observed in black participants. Moreover, race moderated association of perceived social status with depressive symptoms (P<0.001); which mediates the effects of perceived social status on pain outcomes.
Higher perceived social status is associated with less severe depressive symptoms, which in turn is associated with less pain severity and less pain interference for whites but not for blacks with cLBP.