BACKGROUND: Current scales to measure bleeding in clinical trials are inadequate. The aim of this study was to develop a simple, valid, and reliable measurement tool to categorize the severity of bleeding in patients with chemotherapy-induced thrombocytopenia (CIT).

STUDY DESIGN AND METHODS: Measurement theory was used to develop the Bleeding Severity Measurement Scale (BSMS) in four steps: 1) identification of the patient population, 2) item generation and reduction, 3) reviewing the items and formatting the scale, and 4) evaluation of psychometric properties. Feasibility was tested in a pilot study. Content and face validity were assessed by expert review. Psychometric evaluation included determination of intra- and interrater reliability and construct and criterion validity.

RESULTS: The final BSMS defined two grades of bleeding: not clinically significant (Grade 1) and clinically significant (Grade 2). Grade 2 bleeds were defined as bleeds resulting in morbidity, requiring interventions, or directly causing death. The BSMS had excellent interrater (intraclass correlation coefficient [ICC], 0.80) and intrarater (ICC, 1.0) reliability and good construct and criterion validity. The BSMS distinguished between patients with different bleeding severities.

CONCLUSION: Using rigorous methods, we designed a simple bleeding assessment tool with excellent psychometric properties for patients with CIT. Use of this scale in clinical trials should provide valid and reliable assessments of bleeding.