Related Experiment Videos
A new analogue scale for assessing children's pain: an initial validation study
Patricia A McGrath1, Cheryl E Seifert, Kathy N Speechley
1Pediatric Pain Program, University of Western Ontario, Canada Epidemiology Program, Child Health Research Institute and Department of Pediatrics, University of Western Ontario, Canada Department of Communicative Disorders, University of Western Ontario, Canada Biostatistical Resource, Child Health Research Institute, Canada Department of Psychology, Parkwood Hospital, London, Ontario, Canada.
Insights
A new Coloured Analogue Scale (CAS) for children
Area of Science:
- Pediatric Pain Assessment
- Psychometrics
- Clinical Measurement
Background:
- Assessing pain in children requires reliable and valid clinical instruments.
- Existing visual analogue scales (VAS) are effective but can be cumbersome for routine clinical use.
- A novel pocket-sized instrument, the Coloured Analogue Scale (CAS), was developed for assessing children's pain intensity and affect.
Purpose of the Study:
- To determine the validity of the CAS by evaluating its psychophysical properties and discriminant validity.
- To compare the CAS with established visual analogue scales (VAS) in a pediatric population.
- To assess the practicality of the CAS for clinical administration and scoring.
Main Methods:
- A parallel groups design randomized 104 children (ages 5-16) to either the CAS or VAS group.
- Participants completed a calibration task rating circle sizes to evaluate psychophysical properties.
- Children also rated the intensity and affect of painful events using the Children's Pain Inventory (CPI).
Main Results:
- The CAS demonstrated equivalent psychometric properties to the VAS in terms of psychophysical relationships and discriminant validity.
- No significant differences were found in intensity or affective ratings between the CAS and VAS groups.
- The CAS was rated as easier to administer and score than the VAS.
Conclusions:
- The Coloured Analogue Scale (CAS) is a valid and reliable measure for assessing pediatric pain intensity and affect.
- The CAS offers practical advantages over VAS, making it suitable for routine clinical application.
- Further validation through construct validity testing in diverse clinical populations is recommended.
Abstract:
A new instrument was designed to provide a practical clinical measure for assessing children's pain intensity and pain affect. The pocket size measure includes a Coloured Analogue Scale (CAS) to assess intensity and a facial affective scale to assess the aversive component of pain. Both scales have numerical ratings on the back, so that the person administering it can quickly note the numbers that represent a child's pain. This study was conducted to determine the validity of the new instrument by evaluating the psychophysical properties of the intensity scale and by evaluating the discriminant validity of the intensity and affective scales. Since visual analogue scales (VAS) are valid and reliable measures for assessing children's pain, children's ability to use the new analog scale was compared with their performance on a VAS. Children's ability to rate pain affect using an affective scale, in which the 9 faces on a Facial Affective Scale (FAS) are presented in an ordered sequence from least to most distressed, was compared to their performance on the original FAS, in which the same faces were presented in a random order. Using a parallel groups design, 104 children (5-16 years; 60 female, 44 male; 51 healthy and 53 with recurrent headaches) were randomized into two groups: CAS or VAS. Children used the assigned scale to complete a calibration task, in which they rated the sizes of 7 circles varying in area (491, 804, 1385, 2923, 3848, 5675 and 7854 mm2). The psychophysical function relating perceived circle size to actual physical size was determined for the CAS and VAS. Children's CAS and VAS responses on the calibration task yielded similar mathematical relationships: psi cas = 0.035I0.87, psi vas = 0.027I0.89, where psi = perceived magnitude and I = stimulus intensity. The R2 values were 0.921 and 0.922 for the CAS and VAS groups, respectively. Analyses of covariance revealed no significant differences in the characteristics of these relationships, i.e., R2, slope, or y intercept, by scale type. Children used the same scale to complete the Children's Pain Inventory (CPI), in which they rated the intensity and affect of 16 painful events (varying in nature and extent of tissue damage). Children's CAS and VAS responses on the CPI were similar. Analyses of covariance indicated that there were no differences in either intensity or affective ratings by scale type. However, the mean number of painful events experienced by children increased significantly with age (P = 0.0001). Intensity ratings decreased significantly with age (P = 0.002), but affective ratings did not vary with age. The new instrument has equivalent psychometric properties to a 165 mm VAS. However, the CAS was rated as easier to administer and score than the VAS, so it may be more practical for routine clinical use. Since the CAS has fulfilled the first two criteria for a pain measure (psychophysical properties and discriminant validity), it is ethical to proceed with the formal definitive test for construct validity, in which children from various clinical populations use the CAS scale to assess their own pain.