Section 11 Value tree in combination with preference weights

Value tree from BRAT framework with added preference weights

Short name	Description
Name/rubric	Value tree with preference weights
Created in	BRAT Lotus notes program plus power point
Message	To display qualitative listing of available key benefits and risks criteria for the decision model and the description of their measurements in a hierarchical way. Patient preferences on each criterion are also displayed. Colours are used to indicate level of criteria.
Intended audience	Regulators , Physicians, not patients.
Knowledge required	Needs Medical knowledge (terminology of the medical terms; for judging whether selected benefits and risks make sense), no statistical knowledge needed. Understanding of the meaning and role of weights on the value tree is required.
Unintentional message	Risks are weighted very high compared to benefits. Since the probability of event is missing, individuals may quickly judge that risk clearly outweighs benefit.
Message not communicated	The way parameters were measured in the trial (ALT Units etc.) is unclear (but included in value tree in Section 7.4.9. It is also unclear which treatments are being compared, and whose preference weights are being represented.
Proposed improvement	The axis for preference weights should be labelled and the scale is to be made explicit. Whose preference weights are being represented should be made clear through the axis label. The criteria could be ordered by magnitude of weights within the hierarchy. The graph should be accompanied by the frequency of events to allow for appropriate judgment to be made.