The assessment of bleeding patterns in postmenopausal women during continuous combined hormone replacement therapy: a review of methodology and recommendations for reporting of the data

Objectives To systematically review methods used to report data on bleeding patterns among postmenopausal women enrolled in clinical trials of continuous combined hormone replacement therapy (HRT); and to propose the use of standardized terms, definitions, and methods for collecting and reporting bleeding data in such trials. Methods A MEDLINE search identified 18 published reports of bleeding patterns among postmenopausal women enrolled in prospective clinical trials that included a continuous combined HRT treatment arm. Only two of these trials were not randomized. Methods for collecting and analyzing bleeding pattern data were collated from these published reports and examined for consistency. Results Comparisons across studies revealed little consistency in definitions and indices utilized to report bleeding patterns among postmenopausal women administered continuous combined HRT regimens in clinical trials. While a majority of the trials incorporated definitions established by the World Health Organization for the evaluation of bleeding with hormonal contraception, a number of the studies expanded on these definitions to reflect additional dimensions of bleeding such as volume. Indices calculated from daily bleeding data to describe bleeding patterns in treatment groups were highly variable among studies. Conclusion Inconsistencies among clinical trials in bleeding pattern definitions and indices limit understanding and comparison of typical bleeding patterns with continuous combined HRT regimens. Standardized definitions, data collection procedures, and indices are proposed to enhance understanding of bleeding patterns with hormone therapy and enrich the quality of patient counselling on HRT.