Development and Internal Validation of the Postoperative Analgesic Intake Needs Score: A Predictive Model for Post-Operative Narcotic Requirement after Spine Surgery.

Study Design: Retrospective Cohort.

Objective: The aim of this study was to develop a clinical tool to pre-operatively risk-stratify patients undergoing spine surgery based on their likelihood to have high postoperative analgesic requirements.

Methods: A total of 1199 consecutive patients undergoing elective spine surgery over a 2-year period at a single center were included.

Genetic live vaccines mimic the antigenicity but not pathogenicity of live viruses.

The development of an effective HIV vaccine is both a pressing and a formidable problem. The most encouraging results to date have been achieved using live-attenuated immunodeficiency viruses. However, the frequency of pathogenic breakthroughs has been a deterrent to their development.