Reliability Study of the Laparoscopic Skills Index (LSI): a new measure of gynaecologic laparoscopic surgical skills.

Objective: To construct and test the reliability of the Laparoscopic Skills Index (LSI) as a new, multi-item, objective measure of laparoscopic skills in gynaecology.
Methods: Construction of the LSI involved (1). item selection, (2). choosing a method to scale responses, (3). design, and (4). choosing a scoring method. Internal consistency and rater reliability were tested. One community-based gynaecologist (rater A) and 3 teaching faculty gynaecologists (raters B, C, and D) reviewed 20 videotaped gynaecologic laparoscopy operations and scored operator (subject) performance.
Results: Cronbach's a was 0.95, indicating a high level of internal consistency. The intraclass correlation coefficient (ICC) for all 4 raters was 0.51 (95% confidence interval [CI], 0.20-0.76), indicative of moderate interrater reliability. A systematic observer bias was seen wherein rater A's scores closely paralleled, but were consistently higher than, those of raters B, C, and D. The ICC for raters B, C, and D only was 0.77 (95% CI, 0.56-0.90), which is consistent with very good rater agreement.
Conclusion: The LSI appears to have the properties of a reliable, unidimensional index, in which the item variables are true components of the overall attribute, that is, laparoscopic skill.