Intra- and inter-rater agreement of the Genital Injury Severity Scale.

Introduction: The Genital Injury Severity Scale (GISS) is a clinimetrically-tested tool in use for quantifying and qualifying external genital injury after sexual intercourse.

Purpose: To evaluate inter- and intra-rater agreement of the GISS amongst examiner/raters in an urban, ethnically diverse, emergency department based sexual assault center.

Methods: The study was conducted in three phases. Six examiners with various years of experience rated their own cases and each others' cases greater than one year after the initial exam. They rated the photographs and documentation of each case at least one year apart. Another six raters utilized a combination of the photos and documentation simultaneously from the same cases. The evaluation method was the completion of the GISS for each phase.

Results: Based on the experience level of the rater, the differences in overall agreement were not significant. Strength of agreement was highest with the combination of photos and documentation with W ranging from 0.60501 (substantial) to 0.91056 (almost perfect). The GISS variables with the highest level of agreement were tissue break type and toluidine blue uptake type, both with photo evaluation alone and combination of documentation and photos (W = 0.72051 and 0.74599, respectively).

Conclusion: The Genital Injury Severity Scale is a reliable tool to quantify and qualify the severity of external genital injury when used to evaluate a combination of photos and documentation utilizing midlevel providers trained as sexual assault forensic examiners with various years of experience.