DEVELOPMENT OF A DIRECT WEIGHTING PROCEDURE FOR QUALITY-OF-LIFE DOMAINS

The Schedule for the Evaluation of individual Quality of Life allows i ndividuals to nominate the domains they consider most important to the ir quality of life and to use their own value system when describing t he functional status and relative importance of those domains. The wei ghts for domain importance are derived through a procedure called judg ement analysis. As judgement analysis is impractical for individuals w ith cognitive impairment and in many clinical situations, a shorter, d irect weighting procedure has been developed. To test the new procedur e, 40 healthy individuals completed both direct and judgement analysis weightings, at t(1) and 7-10 days later (t(2)). After a further 7-10 days (t(3)) they were asked to identify the weight profiles they had p reviously produced using each method. The weights produced by the two methods differed on average by 7.8 points at t(1) and 7.2 points at t( 2). The direct weights changed on average by 4.5 points from t(1) to t (2), while the judgement analysis weights changed by 8.4 points. At t( 3), 55% of individuals were able to identify the direct weights they h ad previously produced. The new procedure demonstrates stability and v alidity but is not interchangeable with judgement analysis. The most a ppropriate ways of using and interpreting both procedures are discusse d.