CONSTRUCTION AND VALIDATION OF A QUALITY-OF-LIFE QUESTIONNAIRE IN CHRONIC LOWER-LIMB VENOUS INSUFFICIENCY (CIVIQ)

Quality of life may be considerably reduced in patients who are suffer ing from chronic lower limb venous insufficiency, although existing ge neric quality of life instruments (NHP, SF-36 or SIP) cannot completel y identify their specific complaints. The Chronic Venous Insufficiency Questionnaire (CIVIQ) has been developed by iterative process. First, a pilot group of 20 patients was used to identify a number of importa nt features of quality of life affected by venous insufficiency, other than physical symptoms of discomfort. A second study involving 2,001 subjects was used to reduce the number of items. Subjects were asked t o score both the severity of their problems and the importance they at tributed to each problem an a 5-point Likert scale. The importance ite ms found in patients with venous insufficiency were subjected to facto rial analyses (PCA, PAF). The final version is a 20-item self-administ ered questionnaire which explores four dimensions: psychological, phys ical and social functioning and pain. Internal consistency of the ques tionnaire was validated for each dimension (Cronbach's alpha > 0.820 f or three out of four factors). Reproducibility was confirmed in a 60 p atient test-retest study. Pearson's correlation coefficients for both the four dimension subscales and for the global score at 2-week interv als were greater than 0.940. Finally the questionnaire was tested in a randomized clinical trial of 934 patients in order to assess responsi veness and the convergent validity of the instrument, together with th e patient's own quality of life. This study demonstrated that converge nce was valid: Pearson's correlation coefficients between clinical sco re differences and quality of life score differences were small (from 0.199-0.564) but were statistically different from 0 (p < 0.001). Stan dardized response mean (SRM) and effect size (ES) were calculated to a ssess sensitivity to change. SRM and ES both demonstrated considerable responsiveness to change (> 0.80). Reliability, face, content, constr uct validity and responsiveness were also determined for this specific quality of life questionnaire relating to venous insufficiency. Resul ts suggest that this questionnaire may be used with confidence to asse ss quality of life in clinical trials on chronic venous insufficiency.