A Difference-in-Differences Analysis of Low-Value Opioid Utilization for Acute Low Back Pain, 2019-2021

The use of opioids for acute low-back pain (LBP) is considered low-value in most clinical scenarios. Understanding trends in low-value opioid utilization can inform interventions to support guideline-concordant care. This study evaluated the utilization of low-value opioids for acute LBP, and variation by rurality, payer, and sex, before and during the COVID-19 pandemic.

In this retrospective cohort study, we examined opioid claims from Virginia's All-Payer Claims Database among adults with commercial, Medicare Advantage (MA), or Medicaid insurance during 2019-2021. We identified low-value opioid claims for acute LBP and quantified utilization rates per 1,000 patients. Heterogeneous difference-in-differences models generated incidence rate ratios (IRRs) stratified by rurality, payer, and sex to estimate differences between the observed (during-pandemic) and expected (prepandemic) rates.

Among our cohort (n = 853,775), 73.9% of opioids utilized for acute LBP were low-value. Utilization rates declined from 155.0 prescriptions/1,000 patients in 2019 to 107.5 prescriptions/1000 patients in 2021 and were 20.0% lower during the pandemic than expected rates (marginal IRR: 0.80, P = 0.002). Utilization was higher in rural than nonrural areas (marginal IRR: 1.74, P<0.001) without pandemic effect interaction (IRR: 1.02, P = 0.604). The rural effect was smaller for MA beneficiaries (IRR: 0.75, P = 0.046), and larger among males (IRR: 1.25, P<0.001).

The decline in low-value opioid utilization for acute LBP was accelerated during 2020-2021. Utilization was consistently higher in rural than nonrural areas. Findings highlight the need for targeted interventions and policy to reduce low-value opioid utilization, especially in rural areas to ensure equitable, high-value care for acute pain.