Assessing prescribing trends of adjuvant medication therapy in outpatients with a diagnosis of noncancer chronic pain

Background: Chronic pain affects over 100 million adults in the United States, yet continues to be difficult to treat. Concerns continue to mount over the use of opioids to treat noncancer chronic pain (NCCP). Guidelines support the use of adjuvant medications as one of the preferred options for treating chronic pain over opioids. Objectives: To examine reported usage of adjuvants in the treatment of chronic pain via the National Ambulatory Medical Care Survey (NAMCS). Materials and Methods: A retrospective, cross-sectional study evaluating reported usage of adjuvant pain medications for the treatment of NCCP was conducted using NAMCS data from 2000 to 2007. Weighted samples were analyzed with regard to several patient variables. Logistic regression models provided 95% confidence intervals and an adjusted odds ratio to determine statistically significant differences in reported usage for the evaluated patient variables. Results: In total, 244,797,406 weighted visits were included for analysis. The analysis showed an almost 2-fold increase in adjuvant use during the study period. Statistically significant differences were identified for several factors evaluated. Younger age, female sex, care from a nonprimary care physician, comorbidities with pain, and >5 current medications were associated with higher rates adjuvant therapy use. Discussion: Overall adjuvant usage dramatically increased during the study period. Analysis of data demonstrated adjuvant use in chronic pain varied based patient-specific characteristics. These results may allow clinicians, policy makers, and medical educators to identify potential gaps in adjuvant use in certain populations and target areas for clinical, populations-based, and educational improvements in managing NCCP.