Development and validation of an intraoperative bleeding severity scale for use in clinical studies of hemostatic agents.

BACKGROUND

Clinical studies investigating topical hemostatic agents have not used standardized definitions for intraoperative bleeding. The Food and Drug Administration has recently sought use of a validated, clinician-reported scale to standardized bleeding sites in these clinical studies. The intent of a scale is to reduce patient risk, generate labeling claims, and allow comparisons among study results. We describe the development and validation of an intraoperative bleeding severity scale.

METHODS

A concept phase defined the framework of the scale. A feasibility and validation phase investigated the usability, clarity, relevance, and reliability (ie, intra- and interobserver concordance) among surgeons and surgical specialties as required by the Food and Drug Administration for the validation of a clinician-reported scale. Data were collected using an online tool. A total of 144 surgeons participated in the 3 phases.

RESULTS

The scale developed during the concept phase achieved an average intraobserver concordance of 0.97 and an interobserver concordance of 0.89 in the feasibility phase (N = 33); a concordance of 1.0 is perfect. The scale was refined and then achieved an average intraobserver concordance of 0.98 and an interobserver concordance of 0.91 in the validation phase with unanimous agreement by surgeons from multiple surgical specialties that the scale can be implemented into clinical studies (N = 102).

CONCLUSION

This study validated an intraoperative bleeding severity scale for use in clinical studies investigating hemostatic agents. The scale was usable, clear, and clinically relevant with excellent reliability. The scale fulfills requirements of the Food and Drug Administration for a clinician-reported scale and can be used to generate clinically meaningful labeling claims.