What does CIVIQ assess?
The first step recommended by proponents of a specific chronic venous disease (CVD) quality-of-life scale1-4 is the identification of the relevant parameters to assess, based on published information and interviews with experts and patients suffering from CVD. Therefore, venous-related signs and symptoms were combined to assess the impact of disease on the daily life of CVD patients. However, the strength of a quality-of-life questionnaire is determined not only by its content, but also by how it was designed.
Design of CIVIQ
An initial questionnaire was designed to scale the indicators and select the most relevant complaints and their impact on daily life (items). This was done through published information and face-to-face interviews of 24 subjects suffering of CVD. A thousand items were initially collected and a total of 188 most relevant items were selected. The item pool was designed as the basis for the construction of the final questionnaire so it was important to list more parameters than would be used in the final version. The next step was to ask 150 patients suffering from CVD to rank these items in order of importance. The check-list was a 45-item self-administered questionnaire. For each item, two types of questions were formulated. The first concerned the presence and intensity of the impairment experienced, and the second, the level of importance the patient attributed to this impairment. Thus, the ChronIc Venous Insuficiency quality of life Questionnaire (CIVIQ) instrument implicitly integrated patients’ preferences as these constituted the foundations of its structure and were the basis for the choice of the items assessed. This is in line with the recommendations expressed by the Food and Drug Administration (FDA) in the US. With several hundred items initially collected, the CIVIQ questionnaire is likely to cover all aspects of the disease and to reach saturation. According to the FDA, “saturation is reached at the point when no new relevant or important information emerges and collecting additional data will not likely add to the understanding of how patients perceive the concept of interest and the items in the questionnaire.”5 Some experts only include in final questionnaires those items with the highest product between frequency and importance. Others suggest eliminating redundant parameters by principal component analysis and gathering items according to their contribution (loading) to different factors.
In CIVIQ, variables were selected using both methods making it the first CVD-specific quality-of-life questionnaire to be based on such rigorous rules.6-9
References
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- Guyatt GH. Measuring quality of life: a review of means of measurement in clinical trials of new medicines. Pharm Med. 1987;2:49-60.
- Guyatt GH, Veldhuyzen Van Zanten S, Feeny DH, Patrick DL. Measuring quality of life in clinical trials: a taxonomy and review. CMAJ. 1989;140:1441-1448.
- Launois R. A quality-of-life tool kit in venous disorders. Medicographia. 2004;26:152-158.
- US Department of Health and Human Services Food and Drug Administration et al. Guidance for industry patient- reported outcome measures: use in medical product development to support labeling claims.
- Launois R. At the crossroads of venous insufficiency and hemorrhoidal disease: Daflon 500 mg—Repercussions of venous insufficiency on everyday life. Angiology. 1994;45:495-504.
- Launois R, Reboul-Marty J, Henry B. Construction et validation d’un indicateur spécifique de qualité de vie : le cas de l’insuffisance veineuse chronique des membres inférieurs. J Econ Med. 1994;12:109-126.
- Launois R, Reboul-Marty J, Henry B. Construction and validation of a quality of life questionnaire in chronic lower limb venous insufficiency (CIVIQ). Qual Life Res. 1996;5:539-554.
- Launois, R., Mansilha, A., Jantet, G. International psychometric validation of the chronic venous disease quality of life questionnaire CIVIQ-20. Eur J Vasc Endovasc Surg. 2010;40:783-789.