Removal of Non-economic Damage Caps Is Not Associated with Reductions in Early Imaging for Low Back Pain

Background: Supporters of medical liability reform contend that caps on non-economic damages will decrease defensive medicine. Questions/Purposes: We examined whether removal of caps on non-economic damages affect one type of defensive medical practice, early imaging for new-onset low back pain. Patients and Methods: Using administrative claims data, we retrospectively studied adult patients evaluated for new-onset low back pain from 2007 to 2012. We included patients from two states that had caps on non-economic damages struck down in 2010 (n = 462,604) and patients from adjacent states (n = 781,963). Using a difference-in-differences approach, we evaluated the impact of non-economic damage caps on early imaging while adjusting for physician specialty, patient characteristics, and year- and state-level fixed effects. Results: There was no association between non-economic damage caps and early imaging for low back pain among all providers. Removal of a non-economic damage cap was also not associated with a significant change in early imaging within the two cap-removal states. Subgroup analysis by physician specialty demonstrated significantly increased use of early imaging for low back pain by orthopedic or neurological surgeons in the first 12 months following cap removal in one state (but this difference did not persist beyond 12 months). In the other cap-removal state, early imaging increased among orthopedic and neurological surgeons more than 12 months after cap removal. Conclusion: We found no association between caps on non-economic damages and early imaging for low back pain among all physicians. However, our subgroup analysis suggests that physician specialties may respond to non-economic damage cap policies differently.