Hot Off the Press: Hospital Observation Upon Reversal (HOUR) With Naloxone: A Prospective Clinical Prediction Rule Validation Study.

This is a prospective observational study looking to validate a previously derived decision rule designed to help safely discharge opioid overdose patients from the emergency department after 1 hour. They included a convenience sample of 538 adult patients who had received naloxone pre-hospital and compared the Hospital Observation Upon Reversal (HOUR) rule with clinical judgement. The primary outcome of interest was a broadly defined composite of adverse events. The HOUR rule had a sensitivity of 84.1% (95% CI 76.2-92.1%) and a specificity of 62.1% (95% CI 57.6-66.5%), which was very similar to clinical judgement. Clinical judgement would have missed 12 adverse events, while the HOUR rule would have missed 13, although most of those adverse events were probably minor.