HRQOL measurement To measure HRQOL, we used the Euroqol 5-D instrument (6). The Euroqol 5-D is a widely used and validated generic instrument that has five dimensions:mobility,self care,usual activities,pain/discomfort,and anxiety/depression. Each dimension has three levels : no limitations ,some limitations , and severe limitations. As a result,
there are 243 possible sets of values for the Euroqol 5-D(i.e.,35).All of these possible health states have been valued by the general public in the U.K. using the so called York A-1 tariff,by mean sofa large scale time trade-off study(7).These
“valuations”of the health states represent utility values,an indication of their level of desirability or undesirability.The set of possible values has a range of - 0.549 to 1, where 1 indicates perfect health, 0 indicates death,and - 0.549 indicates the
worst possible health state that is viewed by the general public as considerably worse than death.The utility values found in the U.K. study have since been validated for the Netherlands(8).The valuations of patients’ health states are henceforth referred to as EQ5D utility scores.