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

Abstract

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.

Keywords: Addiction; Aging; Alcohol; Gender Differences; Geriatrics; Low Back Pain; Nicotine; Opioids; Pain; Substance Use Disorders.

Figure 1.

Flow chart of LBP and SUD estimation from CMS ICD-10 data. Records in the Medicare Carrier claim file containing one or more claims are accessioned. Claims of those younger than 65 are excluded, and data are classed by age and gender. Data were stratified by presence or absence of LBP, and SUD disorders were evaluated. Denominators are specified in the text. Sixty-eight claims with nonsense codes were excluded from study.

Figure 2.

(A) Rates of “Opioid dependence, uncomplicated” (F11.20) are markedly increased in patients with LBP, by gender and age cohort, compared with those not diagnosed with LBP. (B) Total counts of “Opioid dependence, uncomplicated” (F11.20) for males and females without and with LBP by age cohort demonstrate that patients with LBP account for about half of the total number of patients diagnosed with uncomplicated opioid dependence, the most common opioid use disorder diagnosis.

Figure 3.

Relative rates of most common substance use diagnoses for patients with LBP relative to those without a diagnosis of LBP, for females and males more than 65 years of age, including alcohol, opioids, and nicotine classes. For code annotation, see Table 2. Key: Red bars indicate alcohol rates for those with LBP; blue bars, opioid rates for those with LBP; yellow bars, nicotine rates for those with LBP; light red bars, alcohol rates for those without LBP; light blue bars, opioid rates for those without LBP; and light yellow bars, nicotine rates for those without LBP.