A biopsychosocial path model linking tobacco smoking to the Native American chronic pain disparity: findings from the Oklahoma Study of Native American Pain Risk

Background Among US groups, Native Americans (NAs) have the highest rates of smoking and chronic pain. No study has examined whether smoking contributes to NA chronic pain disparities. Purpose We tested a biopsychosocial model linking smoking with chronic pain among NAs. Methods Social, psychological, and biological variables associated with chronic pain risk and smoking were assessed in healthy, pain-free NAs and non-Hispanic Whites (NHWs). Participants were followed for 5 years to assess who did (N = 49) and did not (N = 151) develop chronic pain (pain rated ≥3/10 on most days lasting ≥3 months). Results Native Americans had higher odds of smoking and developing chronic pain than NHWs, and smoking predicted chronic pain at 5 years (OR = 3.86, 95% CI, 1.59-9.35), even after controlling for age, sex, income, and education, but NA ethnicity did not confer greater chronic pain risk among those that smoke. A path analysis suggested that smoking contributed to the NA chronic pain disparity via 4 indirect paths. One linked NA ethnicity to chronic pain via smoking. Others suggested that the higher smoking rate in NAs was partially explained by interpersonal discrimination, and that cardiometabolic load (stress-related wear-and-tear on cardiovascular/metabolic systems) and impaired physiological pain inhibition (assessed by quantitative sensory testing) linked smoking to NA chronic pain. Conclusions Smoking fits within a biopsychosocial model of NA chronic pain risk. Discrimination is linked to higher rates of smoking among NAs; smoking is associated with the NA chronic pain disparity; and higher cardiometabolic load and impaired pain inhibition link smoking to NA pain disparities.