Objective: A dichotomy exists within the treatment of heavy menstrual bleeding (HMB); guidelines and expert opinion recommend that clinical management be guided by subjective, patient-centered measures, yet clinical trials often describe treatment efficacy in terms of objective reductions in menstrual blood loss (MBL). The purpose of this investigation was to correlate subjective and objective aspects of HMB treatment by identifying the minimum change in MBL that would be considered meaningful to women. Research design and methods: Receiver operating characteristic (ROC) curve analyses were performed using data from a multicenter, randomized, double-blind, placebo-controlled, parallel-group study of a novel, oral formulation of tranexamic acid (Lysteda*). The study enrolled women ages 1849 years with a history of cyclic HMB. Menstrual blood loss was measured objectively using the alkaline hematin method and subjectively using the Menorrhagia Impact Questionnaire (MIQ), a patient-reported outcome instrument previously validated in an HMB population. Additional subgroup analyses were performed after stratification by low (80160mL/cycle) or high (>160mL/cycle) baseline MBL. Clinical trial registration: NCT00401193 (NIH Clinical Trials Registry) Results: A total of 278 women were included in the ROC analyses. The best balance of sensitivity and specificity was achieved for predicting a patient-perceived meaningful improvement in MBL, at a cut point of 36mL/cycle. Absolute reductions in MBL that were considered meaningful were more modest in women with lower baseline MBL (22mL/cycle) and greater in women with higher baseline MBL (47mL/cycle). However, an approximately 22 MBL reduction was meaningful to the majority of women in either the low or high baseline MBL subgroups. Conclusions: Reducing measurable MBL by 36mL/cycle, or approximately 22, was considered to be a meaningful improvement for the majority of women with HMB in this study population. © 2010 Informa UK Ltd All rights reserved.