Reducing the prevalence of low-back pain by reducing the prevalence of psychological distress: Evidence from a natural experiment and implications for health care providers.

OBJECTIVE: To determine whether exogenously reduced psychological distress reduces reported low-back pain (LBP) and is associated with reduced medical visits for LBP. DATA SOURCES: National Health Interview Survey, National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, 1998-2004. STUDY
DESIGN: We estimate a fuzzy regression discontinuity model in which a discontinuity in the prevalence of psychological distress is identified by exogenous national events. We examine whether this discontinuity induced a corresponding discontinuity in the prevalence of LBP. We additionally estimate a regression discontinuity model to determine associated changes in medical visits with LBP as the primary complaint. PRINCIPAL
FINDINGS: The prevalence of LBP was discontinuously reduced by one-fifth due to the exogenous national discontinuous reduction in psychological distress. This discontinuity in LBP cannot be explained by discontinuities in employment, insurance, injuries/poisoning, general health status, or other factors. We find an associated three-fifth discontinuous reduction in medical visits with LBP as the primary complaint.
CONCLUSIONS: On a monthly basis, 2.1 million (P < .01) adults ceased to suffer LBP due to the national reduction in psychological distress, and associated medical visits with LBP as the primary complaint declined by 685 000 (P < .01). © Health Research and Educational Trust.