Materials. Consensus report of Working Group 4.

The method used by the working group was an iterative process based upon a structured review of the relevant literature by a group of rapporteurs. The literature was searched using common databanks (e.g., Medline, Pubmed, Cochrane Library etc.), and also by performing manual searches in the non-indexed literature. The review papers were circulated to the members of the group before and during a conference that served as the basis for subsequent discussions. Each paper was subject to detailed collective analysis and subsequently modified on the basis of panel's discussion and referred to additional relevant literature where appropriate. The consensus statements were prepared after a detailed consideration of the papers submitted to the workshop by the working group. The papers were scrutinized, amended and approved by the group. [ABSTRACT FROM AUTHOR]