Validation of VascuQol-6 Spanish Version

Study Overview
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Brief Summary
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VascuQol (VQ) is a specific questionnaire to assess the quality of life of patients with critical limb ischemia which is also used as an index in vascular registries. The original version has 25 items (VQ-25), divided into 5 subscales or domains: pain, symptoms, activity, social and emotional. The shortened version, VascuQol-6 (VQ-6) is made up of 6 questions and 4 possible answers, which score from 1 (worst quality of life perceived by the patient) to 4 (best quality of life perceived by the patient). The total score is between 6 and 24, and a higher value is related to better health. While the VQ-25 questionnaire has been translated and validated in 21 languages, the shortened version VQ-6 has been translated and validated in some languages, not including Spanish. As it is a fast and easy-to-use tool iwhich has demonstrated statistical validation to measure PAD in other versions of the same questionnaire (other languages), a cross-cultural adaptation and statistical validation of the questionnaire from English to Spanish will be carried out.

Official Title
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Cross-cultural Adaptation and Validation of the VascuQol-6 Spanish Version

Conditions
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Peripheral Artery Disease

Intervention / Treatment
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* Other: VascuQol-6 questionnaire Spanish version


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients over 18 years of age With a diagnosis of Peripheral Arterial Disease (intermittent claudication and critical lower limb ischemia) Whose first language is Spanish Who sign the informed consent. Exclusion Criteria: Patients with cognitive impairment that difficults understanding of the questionnaire

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pre-test group<br>After translation to Spanish, VQ-6 questionnaire is given to 20 patients to assess understanding by the patient. | Other: VascuQol-6 questionnaire Spanish version<br>* VascuQol-6 questionnaire was translated by two professional translators into Spanish.<br>|
| Test and re-test group<br>80 patients will be recruited to answer VQ-6 questionnaire and SF-12 questionnaire. After 3-4 weeks, these patients will be re-asked with the same questionnaires. | Other: VascuQol-6 questionnaire Spanish version<br>* VascuQol-6 questionnaire was translated by two professional translators into Spanish.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reliability | Reliability refers to the degree to which an instrument is capable of measuring without errors. It measures the proportion or variation in the measurements that is due to the diversity of values adopted by the variable and not to the possible systematic or random error. Reliability will be assessed trough Cronbach's alpha coefficient measured for every item of the questionnaire. | 3 -4 weeks from basal | 
| Reproducibility | Reproducibility of intra-observer reliabilty refers to the repeatibility of the instrument, when it is administered with the same method to the same population at two times. Kappa Index will be measured | 3-4 weeks from basal | 
| Validity | Validity is the ability of the questionnaire to measure the construct for which it has been designed. Pearson correlation between the domains of the questionnaire and ABI from each patient will be measured | 3-4 weeks from basal |