Page 21 - EVALUATION OF TREATMENT FOR HEAVY MENSTRUAL BLEEDING by Herman, Malou

Pictorial Blood Assessment Chart and endometrial ablation outcome
Introduction
Heavy menstrual bleeding (HMB) is one of the main reasons to consult a general practitioner or gynaecologist and many treatments options, such as endometrial ablation, are available. HMB is defined as menstruation at regular intervals but with excessive flow and duration. Clinically, HMB is defined as blood loss of more than 80mL per cycle and to diagnose HMB the Pictorial Blood Assessment Chart (PBAC) is used1,2. However, it is unclear if we can also use the PBAC score as an evaluation tool for the treatment effect.
The Pictorial Blood Assessment Chart (PBAC) is a semi-quantitative measurement tool. Women are instructed to count their number of used towels or tampons each day and then divide them by level of soiling. The chart is scored using the scoring system devised by Higham et al. This measurement method has a specificity and sensitivity of 80-90% when compared to the gold standard, alkalin hematin method. Most studies use a score >150 points to define HMB. A PBAC score of 150 correlates with >80mL blood loss. Although 150 points is often used as a frequently chosen cutoff point to diagnose HMB, it is uncertain whether women after treatment are satisfied with a score closely below 150 points. Some women might expect amenorrhea while others could be satisfied with, for example, 50% decrease in score. In the literature, many studies use the height or decrease in PBAC as an outcome parameter. It is, however, unknown what the valuation is of these scores by women suffering HMB.
So, although the PBAC is considered a validated tool to diagnose HMB at a cut- off of 80mL blood loss per cycle, it is unknown if it is a useful tool to assess the effectiveness of HMB treatment, both in a research setting as well as in a clinical setting. Therefore, knowledge on the height of these scores in relation to the valuation of outcome of treatment is of great importance.
Method
Data collection
We used raw individual patient data (IPD) of studies that were collected for an analysis coordinated by the Birmingham Clinical Trials Unit. In 2012, Daniels et al. performed a network meta-analysis comparing the effectiveness of endometrial ablation methods. For this purpose, the study group created a database consisting
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