An assessment of the association between smoking status, pain intensity, and functional interference in patients with chronic pain.

BACKGROUND: This article examines the association between smoking and pain intensity and functional interference in a heterogeneous group of patients evaluated at a tertiary outpatient pain clinic. Current smoking is associated with less favorable clinical presentations.
OBJECTIVE: This study was conducted to determine if the smoking status of patients seen in an outpatient pain clinic is associated with differences in pain intensity and interference.
METHODS: Surveys were mailed to 500 consecutive new patients evaluated at an outpatient pain clinic. Measures included the Brief Pain Inventory (BPI) and the Fagerström Test for Nicotine Dependence (FTND). Univariate analyses compared BPI scores between smokers and non-smokers. Mean BPI scores were compared between smoking status via analysis of covariance (adjusted for demographic variables which differed significantly by smoking status). A p value < or = 0.05 was accepted as significant.
RESULTS: Survey completion rate was 46%, and 14.7% were current smokers. Smokers were younger, and more likely to be male and unemployed. Smokers had higher scores on all the pain intensity BPI scales (p < 0.01), and higher scores (indicating greater functional impairment) on the general activity (p = 0.007), mood (p = 0.003), normal work (p = 0.02), relationships (p = 0.04), sleep (p < 0.001), and life enjoyment (p = 0.03) BPI functional impairment scales. Severe nicotine dependence was associated with greater pain now, (p = 0.05), and greater functional interference on mood (p = 0.005), normal work (p = 0.02) and life enjoyment (p = 0.04) BPI scales.
CONCLUSION: In patients who completed evaluation in an outpatient pain clinic, current cigarette smokers reported significantly greater pain intensity and pain interference with functioning. Symptoms were more pronounced in smokers with more severe nicotine dependence.