Development of the Bleeding and Pelvic Discomfort Scale for Use in Women With Heavy Menstrual Bleeding Associated With Uterine Fibroids.

OBJECTIVES

This study aimed to define a cardinal symptom burden measure based on items from the Uterine Fibroid Symptom and Quality of Life questionnaire for use as a clinical trial endpoint.

METHODS

Exploratory factor analysis was computed to assess the Uterine Fibroid Symptom and Quality of Life symptom severity scale factor structure, using phase 2 data. Pooled blinded data from phase 3 studies were used for the confirmatory factor analysis and the psychometric evaluation of the new measure. Exit interviews in 30 patients from phase 3 studies provided additional qualitative evidence. A meaningful change threshold was determined using anchor-based analyses supported by patient feedback in the exit interviews.

RESULTS

Three factors emerged from the exploratory factor analysis. Factor 1, called the bleeding and pelvic discomfort (BPD) scale, consists of cardinal symptoms, measuring menstrual distress owing to heavy bleeding, passing blood clots, and feeling tightness or pressure in pelvic area. Patients generally understood the items in the scale and the recall period as intended. The BPD scale had good item performance and internal consistency reliability, strong item-to-total correlations, good item discrimination, known-groups validity, and ability to detect change. A 20-point change on the BPD scale was determined as the clinically meaningful change threshold.

CONCLUSIONS

The BPD scale assesses symptom burden owing to bleeding, passing blood clots, and pelvic pressure. The subscale is based on a subset of items selected to measure the cardinal symptoms of uterine fibroids in a clinical trial setting. The responder threshold evaluates whether patients experience a meaningful treatment benefit over the on-treatment period.