Anderson SW, et al. - This study was intended to compare emergency department (ED) length of stay (LOS) between patients treated with opioid analgesia vs non-opioid analgesia for low back pain (LBP) in the ED. Researchers performed a secondary analysis of National Hospital Ambulatory Medical Care Survey data (2014–2015). They enrolled, in the final study sample, adults (age ≥ 18 years) who presented to the ED with a reason for visit or primary diagnosis of LBP. They classified patient visits into two groups based on whether they received opioid analgesia (with or without non-opioid analgesia) or non-opioid analgesia only in the ED. Applying a multivariable linear regression analysis, the correlation between opioid use and ED LOS was tested. From 2014 to 2015, the research sample consisted of a national estimate of approximately 8.6 million ED visits for LBP. It was shown that use of opioids in the ED was correlated with an increased ED LOS, in a nationally representative sample of patient visits to ED due to LBP in the US.