Interval-level measurement with visual analogue scales in Internet-based research: VAS Generator

The present article describes VAS Generator (www.vasgenerator.net), a free Web service for creating a wide range of visual analogue scales that can be used as measurement devices in Web surveys and Web experimentation, as well as for local computerized assessment. A step-by-step example for creating and implementing a visual analogue scale with visual feedback is given. VAS Generator and the scales it generates work independently of platforms and use the underlying languages HTML and JavaScript. Results from a validation study with 355 participants are reported and show that the scales generated with VAS Generator approximate an interval-scale level. In light of previous research on visual analogue versus categorical (e.g., radio button) scales in Internet-based research, we conclude that categorical scales only reach ordinal-scale level, and thus visual analogue scales are to be preferred whenever possibl

Visual Analogue Scales: do they have a role in the measurement of preferences for health states?

Health state preference data are increasingly used to inform national health care resource allocation decisions. In such circumstances it is important to be confident that the data we provide to decision makers is fit for purpose. Whilst there are many unresolved issues in health state preference measurement, there are some areas of agreement on procedures that are inappropriate. The past ten years have seen the publication of a number of papers reporting substantive problems with the use of visual analogue scales to value health states. In this journal Torrance and colleagues reviewed this literature and concluded that Visual Analogue Scales have a limited but useful role in health state preference measurement. In this paper we critically review the arguments advanced by Torrance and colleagues and argue that it is increasingly clear that Visual Analogue Scales are not an appropriate method and that the time has come to accept that VAS should not be used for health state preference measurement

Reducing ceiling effects in the Working Alliance Inventory-Rehabilitation Dutch Version

Purpose: To reduce ceiling effects on domain scores (Task, Goal, and Bond) of the Working Alliance Inventory (WAI)-Rehabilitation Dutch Version by changing response scales and using Visual Analogue Scales (VASs). Methods: Clients, who had at least three treatment sessions prior, randomly received one of the three versions of the WAI-Rehabilitation Dutch Version, using items with a balanced Likert scale, Positive-Packed Likert scale or VAS. Primary outcome was percentage of ceiling effects in total- and domain scores, secondary outcomes were construct validity and internal consistency of the three versions. Results: One hundred and seventy-six clients randomly received a set of questionnaires (one of the three versions of the WAI-Rehabilitation Dutch Version, Session Rating Scale (SRS) and Helping Alliance Questionnaire (HAQ)-II); 152 participants (mean age 51.5 ± 16.3, 106 women) returned the questionnaires. No ceiling effects were present in the total scores of all versions. Significantly fewer ceiling effects were found in the VAS-Version (Goal: 8.0%, Bond: 7.7%) compared to the original (Goal: 18.0%, Bond: 29.8%) and Positive-Packed Version (Goal: 27.1%, Bond: 29.8%). Spearman’s correlations between VAS-Version, SRS and HAQ-II ranged 0.747–0.845. Conclusions: Visual Analogue Scales effectively reduced ceiling effects on domain scores of the WAI-Rehabilitation Dutch Version, while maintaining validity.Implications for RehabilitationVisual Analogue Scales effectively reduced ceiling effects on domain scores of the Working Alliance Inventory-Rehabilitation Dutch Version, while maintaining construct validity.The Working Alliance Inventory version with Visual Analogue Scales can be used in rehabilitation. Visual Analogue Scales effectively reduced ceiling effects on domain scores of the Working Alliance Inventory-Rehabilitation Dutch Version, while maintaining construct validity. The Working Alliance Inventory version with Visual Analogue Scales can be used in rehabilitation.</p

Visual analogue scales for pain assessment in Alzheimer's disease

Background: In earlier studies, pain assessment in patients with Alzheimer’s disease (AD) was conducted by interview, for which reliability is questionable considering the decline in expressive and receptive language abilities in AD. As similar language problems occur in young children, the reliability of pain assessment in this latter population is increased by employing visual analogue scales. Objective: By employing visual analogue scales, the current study investigated whether (1) nondemented elderly persons and AD patients comprehend the purpose of the scales and (2) AD patients, compared to nondemented elderly persons, report suffering less pain intensity and pain affect. Methods: Three visual analogue scales, i.e. the Colored Analogue Scale (CAS), the Faces Pain Scale (FPS), and the Facial Affective Scale (FAS) were administered to patients in an early and midstage of AD and to nondemented elderly persons. Results: The results show that the percentage of subjects who comprehended the CAS, FAS and FPS was for the nondemented elderly persons 100, 75 and 100%, respectively, for the early AD group 100, 50 and 60%, respectively, and for the midstage AD group 80, 20 and 30%, respectively. Furthermore, elderly persons without dementia reported experiencing more intense pain and pain affect than the early and midstage AD group. Interestingly, the early and midstage AD patients did not differ in reporting pain affect. Conclusion: Visual analogue scales may improve pain assessment in those AD patients who fully comprehend the meaning of the scales. As only the minority of midstage AD patients understood the purpose of the FAS and FPS, the search for tools, particularly to assess pain affect in this population, must continue

Changes in the quality of life in severely disabled people following provision of powered indoor/outdoor chairs

Purpose:To determine the benefits for patients who received an Electric Powered Indoor/outdoor Chair (EPIOC) and to quantify their perceived changes to their quality of life. Method: Community-based cohort study of all patients provided with an EPIOC over 4 months; and followed up about 3 months later in a community served by a regional wheelchair service in North West London (population about 3.1 million) using the EuroQol EQ-5D with visual analogue scales for each of the 5 dimensions of the EQ-5D. Results: Sixty-four wheelchair users were assessed initially and 51 completed follow up. Chair users showed no significant improvement in health state as measured by the EQ-5D after EPIOC provision. The visual analogue scales (VASs) indicated that, although perceived overall health state, independence and social life did not appear to improve, the dimensions of mobility, quality of life and pain/discomfort improved significantly on provision of an EPIOC. Conclusion: EPIOC users reported significant improvements in several important aspects of their lives; not just in mobility (as expected) but also in reduction of pain and discomfort. The use of VASs provided a more holistic set of outcome measures that demonstrate quality of life benefits beyond that of health state alone

Measuring Change with Multiple Visual Analogue Scales: Application to Tense Arousal

International audienceAlthough the visual analogue scale (VAS) may be useful for measuring change on subjective and potentially transient phenomena, there is concern about the reliability and construct validity of the associated measurement variables. The present study reports evidence for tau-equivalence of change scores associated with VASs designed for assessing tense arousal with synonymous indicators. This psychometric property allows an estimation of the truescore structure of the cross-sectional measurement variables in a longitudinal SEM model, including method e ects. Findings suggest that VASs associated with synonymous indicators may yield highly reliable measurement variables. However, imperfect dynamic bipolarity was observed when data based on antonymous indicators were introduced into the analyses, a rather puzzling e ect, which deserves further elaboration

Assessing Mood Change With Visual Analogue Scales: Composite Versus Vectorial Approaches

We examined the assessment of mood change using multiple visual analogue scales from the perspectives of computing a composite difference score and verifying the vectorial comparability of test and retest ratings. The composite approach raises the question of whether the true score can measure mood and whether valid conclusions can be derived from true-score differences within individual data. The vectorial approachallows clinicians to use the data to test the causal and functional conception of ordinal measurability of patients' mood. This falsificationistapproach may lead clinicians to recognize that, in some cases, ratings are not measurements and should be treated as speech acts in a conversational setting

The PedsQL™ Present Functioning Visual Analogue Scales: preliminary reliability and validity

BACKGROUND: The PedsQL™ Present Functioning Visual Analogue Scales (PedsQL™ VAS) were designed as an ecological momentary assessment (EMA) instrument to rapidly measure present or at-the-moment functioning in children and adolescents. The PedsQL™ VAS assess child self-report and parent-proxy report of anxiety, sadness, anger, worry, fatigue, and pain utilizing six developmentally appropriate visual analogue scales based on the well-established Varni/Thompson Pediatric Pain Questionnaire (PPQ) Pain Intensity VAS format. METHODS: The six-item PedsQL™ VAS was administered to 70 pediatric patients ages 5–17 and their parents upon admittance to the hospital environment (Time 1: T1) and again two hours later (Time 2: T2). It was hypothesized that the PedsQL™ VAS Emotional Distress Summary Score (anxiety, sadness, anger, worry) and the fatigue VAS would demonstrate moderate to large effect size correlations with the PPQ Pain Intensity VAS, and that patient" parent concordance would increase over time. RESULTS: Test-retest reliability was demonstrated from T1 to T2 in the large effect size range. Internal consistency reliability was demonstrated for the PedsQL™ VAS Total Symptom Score (patient self-report: T1 alpha = .72, T2 alpha = .80; parent proxy-report: T1 alpha = .80, T2 alpha = .84) and Emotional Distress Summary Score (patient self-report: T1 alpha = .74, T2 alpha = .73; parent proxy-report: T1 alpha = .76, T2 alpha = .81). As hypothesized, the Emotional Distress Summary Score and Fatigue VAS were significantly correlated with the PPQ Pain VAS in the medium to large effect size range, and patient and parent concordance increased from T1 to T2. CONCLUSION: The results demonstrate preliminary test-retest and internal consistency reliability and construct validity of the PedsQL™ Present Functioning VAS instrument for both pediatric patient self-report and parent proxy-report. Further field testing is required to extend these initial findings to other ecologically relevant pediatric environments