A COMPARISON OF DIFFERENT ITALIAN CF-EQ VAS VERSIONS: MARKING, SCORING OR DRAWING A LINE?

Rationale Within the Child-Friendly (CF) EQ harmonization project the VAS is still considered a research topic that needs investigation. UK CF-EQ 5D version (Hennessy and Kind, 2002) utilises the standard VAS version (i.e. “draw a line from the box to the scale”) with modified language in order to be suitable for children. No consideration was made in terms of which task methodology is better in order to let the children better comprehend and right execute the VAS instructions. Question Since previous experiences in child administration show that a correct completion of the VAS prove difficult, (Hale et al, 2004) within Italian translation and testing project of the CF EQ 5D questionnaire the reasons of these difficulties were questioned. The present work will pertain the comparison of different VAS options: • 3 tasks: “drawing a line” (a modified version of) vs “marking” vs “scoring” • 2 different graduated scale formats: 10 by 10 vs 5 by 5 units graduated format. Objective We aimed at testing some psychometric proprieties of the 3 tasks and investigating the attraction effect of the 2 different scale formats. Study sample : A sample of children and adolescents aged between 8 and 15 years was selected, resident in several geographic areas of Italy and partly healthy and partly non healthy. A parent of some participants were also interviewed. An informed consent had to be signed from both the child/adolescent invited to participate and his/her parent. Results and discussion According to the results of questionnaire submission and with the contribution of cognitive interviews we can say that the completion of Italian version of the UK CF-VAS questionnaire shows problems with the comprehensibility and the feasibility. Most of the young people and some parents required the help of the interviewer and several interviewees wrongly completed the instrument. On the other hand, the scores obtained with the VAS by the young respondents directly correlated with the vote given to their health: these findings would suggest that the VAS is a valid questionnaire for young people. Notice that the interviewer often helped the interviewees during completion, probably clarifying the kind of information required, then allowing the right scoring of their own health. TASKS: The feasibility and the comprehensibility of every task appears quite poor. Anyway some differences must be highlighted. Although children show preferences towards the scoring task (in their opinion it is easier because you just have to write the number in the box) evidence on the feasibility of the exercise suggest the marking task as the most appropriate (lowest frequency of wrong exercises). The reason is probably attributable, at least in part, to the fact that marking the scale can be more intuitive: in fact some respondents marked the scale before reading all the instructions in the instruments. SCALE FORMATS: Since children seems to be influenced by the graduated scale format, 5 by 5 units scale format allows respondents to indicate a more specific value, furthermore they declare to have a wider choice with this format. It could be interesting to take into consideration this aspect in the context of the detection of Minimal Important Differences of QoL levels. SEQUENCE OF INSTRUCTION: The first sentence of the VAS section that states:”Indicate on this scale how good or bas is your health..” might induce respondents to execute the task before reading the next instructions. Sentences on this section should follow logical sequence of specification of: objective (what we would like to know), introduction and description of instrument and how to do the task. In order to encourage and to guide the respondents to read all the content of and to correctly complete the instrument, we arranged a proposal of a new Italian CF VAS questionnaire.