Low Back Pain and Substance Use: Diagnostic and Administrative Coding for Opioid Use and Dependence Increased in U.S. Older Adults with Low Back Pain

Objective: Low back pain (LBP) is a leading cause of pain and disability. Substance use complicates the management of LBP, and potential risks increase with aging. Despite implications for an aging, diverse U.S. population, substance use and LBP comorbidity remain poorly defined. The objective of this study was to characterize LBP and substance use diagnoses in older U.S. adults by age, gender, and race. Design: Cross-sectional study of a random national sample. Subjects: Older adults including 1,477,594 U.S. Medicare Part B beneficiaries. Methods: Bayesian analysis of 37,634,210 claims, with 10,775,869 administrative and 92,903,649 diagnostic code assignments. Results: LBP was diagnosed in 14.8±0.06% of those more than 65 years of age, more in females than in males (15.8±0.08% vs. 13.4±0.09%), and slightly less in those more than 85 years of age (13.3±0.2%). Substance use diagnosis varied by substance: nicotine, 9.6±0.02%; opioid, 2.8±0.01%; and alcohol, 1.3±0.01%. Substance use diagnosis declined with advancing age cohort. Opioid use diagnosis was markedly higher for those in whom LBP was diagnosed (10.5%) than for those not diagnosed with LBP (1.5%). Most older adults (54.9%) with an opioid diagnosis were diagnosed with LBP. Gender differences were modest. Relative rates of substance use diagnoses in LBP were modest for nicotine and alcohol. Conclusions: Older adults with LBP have high relative rates of opioid diagnoses, irrespective of gender or age. Most older adults with opioid-related diagnoses have LBP, compared with a minority of those not opioid diagnosed. In caring for older adults with LBP or opioid-related diagnoses, health systems must anticipate complexity and support clinicians, patients, and caregivers in managing pain comorbidities. Older adults may benefit from proactive incorporation of non-opioid pain treatments. Further study is needed.