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Interpretation of the Large Red-and-White Visual Analog Scale by Children Compared With Adults
INTERNATIONAL PEDIATRIC NURSING Column Editor: Bonnie Holaday, DNS, RN, FAAN
Interpretation of the Large Red-and-White Visual Analog Scale by Children Compared With Adults Katri Hamunen, MD, DSc Eeva-Liisa Maunuksela, MD, DSc Klaus T. Olkkola, MD
The red-and-white visual analog scale (VAS) is a modification of the traditional VAS. The purpose of this study was to compare how children of various ages and adults rate their anticipatory pain intensity on the red-and-white VAS. One hundred children were interviewed as part of the anesthesiologist’s preoperative visit before elective eye surgery. For comparison, 50 healthy adults were interviewed in a similar manner. The medians and ranges describing mild, moderate, and severe pain, or pain intensity at which medicine would be requested, did not differ between preschool children, young schoolchildren, and adolescents or between children and adults. The median score of anticipated need for pain medication was 50% of the maximum for children. n 2008 Elsevier Inc. All rights reserved.
EASUREMENT OF PAIN is an integral part of patient care and analgesic studies. Also, in children, self-report of pain is the gold standard whenever possible. Red-and-white visual analog scale (VAS) is a modification of the traditional VAS. The red-and-white, 50-cm-long VAS (Tigerstedt & Tammisto, 1988) is used as a pain assessment tool in clinical practice and analgesic studies both in adults and children (Kalso et al., 1991; Maunuksela, Olkkola, & Korpela, 1987). Postoperative pain intensity scores that children report on this scale correlate well with their verbal description and with the observer’s
M
From the Department of Anaesthesia and Intensive Care Medicine, Helsinki University Central Hospital, Helsinki, Finland, Eye Hospital, Helsinki University Central Hospital, Helsinki, Finland, and Department of Anaesthesiology and Intensive Care, Turku University Central Hospital, Turku, Finland. Corresponding author. Katri Hamunen, Department of Anaesthesia and Intensive Care Medicine, Helsinki University Central Hospital, P.O. Box 340, FIN-00029 HUS Helsinki, Finland. E-mail: [email protected]. 0882-5963/$ - see front matter n 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.pedn.2006.05.014
142
assessment of pain (Maunuksela et al., 1987). The purpose of this study was to compare how children of various ages and adults rate their anticipatory pain intensity on the red-and-white VAS.
METHODS After institutional approval, as part of the anesthesiologist’s preoperative visit, the scale was introduced to 100 consecutive boys and girls aged 5 to 16 years coming to elective inpatient eye surgery. Children participating in the study were classified according to the American Society of Anesthesiologists’ physical status (I–III) and were free of mental and physical disease that might interfere with pain perception or verbal communication. They were interviewed by the same person (E.-L.M.), using standard questions. Previous medical or pain experience was not recorded. The red-and-white, 50-cm-long VAS used in this study is shown in Figure 1. On the backside of the scale, there is a 0–50 scale for the numeric recording of pain intensity. First, the scale was introduced to the child by asking which color, red or white, represents pain for him or her. If the child answered
Journal of Pediatric Nursing, Vol 23, No 2 (April), 2008
143
RED-AND WHITE VAS BY CHILDREN COMPARED WITH ADULTS
Figure 1. The red-and-white, 50-cm-long VAS used in this study.
white, he or she could not use the scale and was not included. The extremes were told to be bno painQ at the white end and bpain as bad as it can beQ at the red end. Then, the following were asked: bWhere would you point if you mean to tell it hurts a lot?Q, bWhere would you point if you mean to tell it hurts a little?Q, bIs there a pain that is more than a little but less than a lot, like moderate pain, medium strong pain? Where would you point that?Q, and bHow big is the pain when you would like to get pain medicine?Q For comparison, 50 working-age adults, cleaning personnel, secretaries, nurses, and doctors of one operating room not involved in pain research or management were interviewed in a similar manner. The children and adults had a possibility of showing either a point or a range. For statistical analysis, we used analysis of variance and chi-square test to compare variables between the groups; p b .05 was considered to indicate significant difference. RESULTS The demographic data are presented in Table 1. There were more females than males in all groups. The children’s results are presented in three age groups: Group I, b7 years; Group II, 7 to 10 years; and Group III, 11 to 16 years. The medians and ranges describing mild, moderate, and severe pain, or pain intensity at which medicine would be requested, did not differ between age groups or between children and adults (Table 2). However, 34%, 24%, and 10% of Groups I, II, and III, respectively, did not recognize moderate pain. In adults, the frequency was 8%. The difference between children and adults was significant ( p b .025). For mild and severe pain, adults showed significantly more often a range, whereas children showed a point ( p b .001). The pain expression of boys and girls did not differ. The median scores for mild, moderate, and severe pain were 7, 24, and 42.5 for boys and 7, 24, and 41.5 for girls, respectively. The median score of need for pain medication was 25 for both genders. DISCUSSION Pain has been advocated as the fifth vital sign by the American Pain Society. Pain should be measured
and recorded regularly in all hospitalized patients. Also, self-report is the gold standard of pain measurement in children whenever possible. Various self-report scales have been designed for children. These include scales of facial expression, color analog scales, and ordinal rating scales (McGrath & Unruh, 1999). The red-and-white modification, 50-cm-long VAS was originally developed for adults in the 1980s. Since that time, it has been used as a pain assessment tool in clinical practice and analgesic studies both in adults (Kalso et al., 1991) and children (Maunuksela et al., 1987). Because of the size and colors, it is easy for patients following eye surgery to both handle and see it. Therefore, it is used in the clinical practice of our hospital. This study shows that the verbal expression for mild, moderate, and severe pain is interpreted similarly on the VAS by children more than 5 years and by adults, using the red-and-white VAS. However, what children mean by mild, moderate, and severe pain might be very different to adults (McGrath, Cunningham, Goodman, & Unruh, 1986; McGrath & Unruh, 1999). Children in general have less experience of pain than adults. A number of studies have shown that younger children rate acute needle pain higher compared with older children (Arts et al., 1994; Fradet, McGrath, Kay, Adams, & Luke, 1990; Goodenough et al., 1999). The reason for this is not entirely clear (Goodenough et al., 1999). To our knowledge, there are no direct comparisons between children and adults. Previous studies in children have reported pain treatment thresholds from 39% (Demyttenaere, Finley, Johnston, & McGrath, 2001) to 53% of the maximum (Gauthier, Finley, & McGrath, 1998). These thresholds are in the same range as the thresholds of the maximum found in this study (48–58%). In this study, there was no difference in the anticipatory pain treatment thresholds between children and adults. VAS scores describing mild and moderate pain (14% and 46% of the maximum, respectively) were somewhat lower than in two previous reports in adults. Severe pain was 85% of the Table 1. Demographic Data of the Participants
Children Total b7 years 7–10 years 11–16 years Adults
n
Male/Female
100 34 46 20 50
39/61 13/21 17/29 9/11 19/31
Age in Years, Median (Range)
8.7 6.0 8.9 12.8 32.6
(5.0–16.9) (5.0–6.9) (7.0–10.9) (11.3–16.9) (20–59)
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Table 2. VAS Pain Scores Describing Mild, Moderate, and Severe Pain and Pain Intensity at Which Medicine Would Be Requested in Children and Adults on a 0–50 Scale n
Children b7 years 7–10 years 11–16 years Adults
34 46 20 50
Mild Pain
Moderate Pain
8 7 7 7
24.0 25.0 21.5 23.0
(0–39) (0–21) (2–20) (0–19)
(5–30) (18–31) (19–35) (12–35)
Severe Pain
42.5 42.0 41.5 42.5
(32–48) (30–50) (28–50) (33–47)
Pain Medication Requested/Percentage of Maximum
25.5 (10–46)/51% 29.0 (4–48)/58% 24.0 (15–40)/48% 24.5 (8–43)/49%
Note. Data are expressed as median (range).
maximum. A meta-analysis of VAS scores from postoperative analgesic studies in adults showed that the mean VAS score for moderate and severe pain was 49 and 75 mm, respectively (Collins, Moore, & McQuay, 1997). In another study (Jensen, Chen, & Brugger, 2003), mean values for mild, moderate, and severe pain were 26–28, 56–58, and 83–87 mm, respectively, depending on the pain model. There were no gender differences in the reported VAS scores. This may partly be explained by the fact that there were more females than males in all study groups. In children, findings on the effect of gender on amount of pain reported
have been very variable (Cepeda & Carr, 2003; Gauthier et al., 1998; Goodenough et al., 1999). In many reports, adult women have reported more pain compared with men (Logan & Rose, 2004; Taenzer, Clark, & Curry, 2000), and gender has been considered as a confounding factor in analgesic studies (Rosseland & Stubhaug, 2004). In conclusion, VAS scores used to describe anticipatory mild, moderate, and severe pain did not differ between children and adults. Further studies are needed to investigate how anticipated pain levels and pain treatment thresholds correlate to those measured postoperatively in children.
REFERENCES Arts, S. E., Abu-Saad, H. H., Champion, G. D., Crawford, M. R., Fisher, R. J., Juniper, K. H., et al. (1994). Age-related response to lidocaine–prilocaine (EMLA) emulsion and effect of music distraction on the pain of intravenous cannulation. Pediatrics, 93, 97 – 801. Cepeda, M. S., & Carr, D. B. (2003). Women experience more pain and require more morphine than men to achieve a similar degree of analgesia. Anesthesia and Analgesia, 97, 1464 – 1468. Collins, S. L., Moore, R. A., & McQuay, H. J. (1997). The visual analog pain intensity scale: What is moderate pain in millimetres? Pain, 72, 95 – 97. Demyttenaere, S., Finley, G. A., Johnston, C. C., & McGrath, P. J. (2001). Pain treatment thresholds in children after major surgery. Clinical Journal of Pain, 17, 173 – 177. Fradet, C., McGrath, P. J., Kay, J., Adams, S., & Luke, B. A. (1990). A prospective survey of reactions to blood tests by children and adolescents. Pain, 40, 53 – 60. Gauthier, J. C., Finley, G. A., & McGrath, P. J. (1998). Children’s self-report of postoperative pain intensity and treatment threshold: Determining the adequacy of medication. Clinical Journal of Pain, 14, 116 – 120. Goodenough, B., Thomas, W., Champion, G. D., Perrott, D., Taplin, J. E., von Baeyer, C. L., et al. (1999). Unravelling age effects and sex differences in needle pain: Ratings of sensory intensity and unpleasantness of venipuncture pain by children and their parents. Pain, 80, 179 – 190. Jensen, M. P., Chen, C., & Brugger, A. M. (2003). Interpretation of visual analog scale ratings and change scores:
A reanalysis of two clinical trials of postoperative pain. Journal of Pain, 4, 407 – 414. Kalso, E., Pfyhi7, R., Onnela, P., Linko, K., Tigerstedt, I., & Tammisto, T. (1991). Intravenous morphine and oxycodone for pain after abdominal surgery. Acta Anaesthesiologica Scandinavica, 35, 642 – 646. Logan, D. E., & Rose, J. B. (2004). Gender differences in postoperative pain and patient controlled. Analgesia use among adolescent surgical patients. Pain, 109, 481– 487. Maunuksela, E.-L., Olkkola, K. T., & Korpela, R. (1987). Measurement of pain in children with self-reporting and behavioural assessment. Clinical Pharmacology and Therapeutics, 42, 137 – 141. McGrath, P. J., Cunningham, S. J., Goodman, J. T., & Unruh, A. (1986). The clinical measurement of pain in children: A review. Clinical Journal of Pain, 221 – 227. McGrath, P. J., & Unruh, A. M. (1999). Measurement and assessment of paediatric pain. In E. D. Wall, R. Melzack, (Eds.) Textbook of pain, 4th ed. (pp. 371 – 394). Edingburgh: Churchill Livingstone. Rosseland, L. A., & Stubhaug, A. (2004). Gender is confounding factor in pain trials: Women report more pain than men after arthroscopic surgery. Pain, 112, 248 – 253. Taenzer, A. H., Clark, C., & Curry, C. S. (2000). Gender affects report of pain and function after arthroscopic anterior cruciate ligament reconstruction. Anesthesiology, 93, 670 – 675. Tigerstedt, I., & Tammisto, T. (1988). A modified visual analog scale (VAS) for evaluation of pain intensity during immediate postoperative recovery. Schmerz Pain Doleur, 9, 27 – 31.
Interpretation of the Large Red-and-White Visual Analog Scale by Children Compared With Adults Katri Hamunen, MD, DSc Eeva-Liisa Maunuksela, MD, DSc Klaus T. Olkkola, MD
The red-and-white visual analog scale (VAS) is a modification of the traditional VAS. The purpose of this study was to compare how children of various ages and adults rate their anticipatory pain intensity on the red-and-white VAS. One hundred children were interviewed as part of the anesthesiologist’s preoperative visit before elective eye surgery. For comparison, 50 healthy adults were interviewed in a similar manner. The medians and ranges describing mild, moderate, and severe pain, or pain intensity at which medicine would be requested, did not differ between preschool children, young schoolchildren, and adolescents or between children and adults. The median score of anticipated need for pain medication was 50% of the maximum for children. n 2008 Elsevier Inc. All rights reserved.
EASUREMENT OF PAIN is an integral part of patient care and analgesic studies. Also, in children, self-report of pain is the gold standard whenever possible. Red-and-white visual analog scale (VAS) is a modification of the traditional VAS. The red-and-white, 50-cm-long VAS (Tigerstedt & Tammisto, 1988) is used as a pain assessment tool in clinical practice and analgesic studies both in adults and children (Kalso et al., 1991; Maunuksela, Olkkola, & Korpela, 1987). Postoperative pain intensity scores that children report on this scale correlate well with their verbal description and with the observer’s
M
From the Department of Anaesthesia and Intensive Care Medicine, Helsinki University Central Hospital, Helsinki, Finland, Eye Hospital, Helsinki University Central Hospital, Helsinki, Finland, and Department of Anaesthesiology and Intensive Care, Turku University Central Hospital, Turku, Finland. Corresponding author. Katri Hamunen, Department of Anaesthesia and Intensive Care Medicine, Helsinki University Central Hospital, P.O. Box 340, FIN-00029 HUS Helsinki, Finland. E-mail: [email protected]. 0882-5963/$ - see front matter n 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.pedn.2006.05.014
142
assessment of pain (Maunuksela et al., 1987). The purpose of this study was to compare how children of various ages and adults rate their anticipatory pain intensity on the red-and-white VAS.
METHODS After institutional approval, as part of the anesthesiologist’s preoperative visit, the scale was introduced to 100 consecutive boys and girls aged 5 to 16 years coming to elective inpatient eye surgery. Children participating in the study were classified according to the American Society of Anesthesiologists’ physical status (I–III) and were free of mental and physical disease that might interfere with pain perception or verbal communication. They were interviewed by the same person (E.-L.M.), using standard questions. Previous medical or pain experience was not recorded. The red-and-white, 50-cm-long VAS used in this study is shown in Figure 1. On the backside of the scale, there is a 0–50 scale for the numeric recording of pain intensity. First, the scale was introduced to the child by asking which color, red or white, represents pain for him or her. If the child answered
Journal of Pediatric Nursing, Vol 23, No 2 (April), 2008
143
RED-AND WHITE VAS BY CHILDREN COMPARED WITH ADULTS
Figure 1. The red-and-white, 50-cm-long VAS used in this study.
white, he or she could not use the scale and was not included. The extremes were told to be bno painQ at the white end and bpain as bad as it can beQ at the red end. Then, the following were asked: bWhere would you point if you mean to tell it hurts a lot?Q, bWhere would you point if you mean to tell it hurts a little?Q, bIs there a pain that is more than a little but less than a lot, like moderate pain, medium strong pain? Where would you point that?Q, and bHow big is the pain when you would like to get pain medicine?Q For comparison, 50 working-age adults, cleaning personnel, secretaries, nurses, and doctors of one operating room not involved in pain research or management were interviewed in a similar manner. The children and adults had a possibility of showing either a point or a range. For statistical analysis, we used analysis of variance and chi-square test to compare variables between the groups; p b .05 was considered to indicate significant difference. RESULTS The demographic data are presented in Table 1. There were more females than males in all groups. The children’s results are presented in three age groups: Group I, b7 years; Group II, 7 to 10 years; and Group III, 11 to 16 years. The medians and ranges describing mild, moderate, and severe pain, or pain intensity at which medicine would be requested, did not differ between age groups or between children and adults (Table 2). However, 34%, 24%, and 10% of Groups I, II, and III, respectively, did not recognize moderate pain. In adults, the frequency was 8%. The difference between children and adults was significant ( p b .025). For mild and severe pain, adults showed significantly more often a range, whereas children showed a point ( p b .001). The pain expression of boys and girls did not differ. The median scores for mild, moderate, and severe pain were 7, 24, and 42.5 for boys and 7, 24, and 41.5 for girls, respectively. The median score of need for pain medication was 25 for both genders. DISCUSSION Pain has been advocated as the fifth vital sign by the American Pain Society. Pain should be measured
and recorded regularly in all hospitalized patients. Also, self-report is the gold standard of pain measurement in children whenever possible. Various self-report scales have been designed for children. These include scales of facial expression, color analog scales, and ordinal rating scales (McGrath & Unruh, 1999). The red-and-white modification, 50-cm-long VAS was originally developed for adults in the 1980s. Since that time, it has been used as a pain assessment tool in clinical practice and analgesic studies both in adults (Kalso et al., 1991) and children (Maunuksela et al., 1987). Because of the size and colors, it is easy for patients following eye surgery to both handle and see it. Therefore, it is used in the clinical practice of our hospital. This study shows that the verbal expression for mild, moderate, and severe pain is interpreted similarly on the VAS by children more than 5 years and by adults, using the red-and-white VAS. However, what children mean by mild, moderate, and severe pain might be very different to adults (McGrath, Cunningham, Goodman, & Unruh, 1986; McGrath & Unruh, 1999). Children in general have less experience of pain than adults. A number of studies have shown that younger children rate acute needle pain higher compared with older children (Arts et al., 1994; Fradet, McGrath, Kay, Adams, & Luke, 1990; Goodenough et al., 1999). The reason for this is not entirely clear (Goodenough et al., 1999). To our knowledge, there are no direct comparisons between children and adults. Previous studies in children have reported pain treatment thresholds from 39% (Demyttenaere, Finley, Johnston, & McGrath, 2001) to 53% of the maximum (Gauthier, Finley, & McGrath, 1998). These thresholds are in the same range as the thresholds of the maximum found in this study (48–58%). In this study, there was no difference in the anticipatory pain treatment thresholds between children and adults. VAS scores describing mild and moderate pain (14% and 46% of the maximum, respectively) were somewhat lower than in two previous reports in adults. Severe pain was 85% of the Table 1. Demographic Data of the Participants
Children Total b7 years 7–10 years 11–16 years Adults
n
Male/Female
100 34 46 20 50
39/61 13/21 17/29 9/11 19/31
Age in Years, Median (Range)
8.7 6.0 8.9 12.8 32.6
(5.0–16.9) (5.0–6.9) (7.0–10.9) (11.3–16.9) (20–59)
144
HAMUNEN, MAUNUKSELA AND OLKKOLA
Table 2. VAS Pain Scores Describing Mild, Moderate, and Severe Pain and Pain Intensity at Which Medicine Would Be Requested in Children and Adults on a 0–50 Scale n
Children b7 years 7–10 years 11–16 years Adults
34 46 20 50
Mild Pain
Moderate Pain
8 7 7 7
24.0 25.0 21.5 23.0
(0–39) (0–21) (2–20) (0–19)
(5–30) (18–31) (19–35) (12–35)
Severe Pain
42.5 42.0 41.5 42.5
(32–48) (30–50) (28–50) (33–47)
Pain Medication Requested/Percentage of Maximum
25.5 (10–46)/51% 29.0 (4–48)/58% 24.0 (15–40)/48% 24.5 (8–43)/49%
Note. Data are expressed as median (range).
maximum. A meta-analysis of VAS scores from postoperative analgesic studies in adults showed that the mean VAS score for moderate and severe pain was 49 and 75 mm, respectively (Collins, Moore, & McQuay, 1997). In another study (Jensen, Chen, & Brugger, 2003), mean values for mild, moderate, and severe pain were 26–28, 56–58, and 83–87 mm, respectively, depending on the pain model. There were no gender differences in the reported VAS scores. This may partly be explained by the fact that there were more females than males in all study groups. In children, findings on the effect of gender on amount of pain reported
have been very variable (Cepeda & Carr, 2003; Gauthier et al., 1998; Goodenough et al., 1999). In many reports, adult women have reported more pain compared with men (Logan & Rose, 2004; Taenzer, Clark, & Curry, 2000), and gender has been considered as a confounding factor in analgesic studies (Rosseland & Stubhaug, 2004). In conclusion, VAS scores used to describe anticipatory mild, moderate, and severe pain did not differ between children and adults. Further studies are needed to investigate how anticipated pain levels and pain treatment thresholds correlate to those measured postoperatively in children.
REFERENCES Arts, S. E., Abu-Saad, H. H., Champion, G. D., Crawford, M. R., Fisher, R. J., Juniper, K. H., et al. (1994). Age-related response to lidocaine–prilocaine (EMLA) emulsion and effect of music distraction on the pain of intravenous cannulation. Pediatrics, 93, 97 – 801. Cepeda, M. S., & Carr, D. B. (2003). Women experience more pain and require more morphine than men to achieve a similar degree of analgesia. Anesthesia and Analgesia, 97, 1464 – 1468. Collins, S. L., Moore, R. A., & McQuay, H. J. (1997). The visual analog pain intensity scale: What is moderate pain in millimetres? Pain, 72, 95 – 97. Demyttenaere, S., Finley, G. A., Johnston, C. C., & McGrath, P. J. (2001). Pain treatment thresholds in children after major surgery. Clinical Journal of Pain, 17, 173 – 177. Fradet, C., McGrath, P. J., Kay, J., Adams, S., & Luke, B. A. (1990). A prospective survey of reactions to blood tests by children and adolescents. Pain, 40, 53 – 60. Gauthier, J. C., Finley, G. A., & McGrath, P. J. (1998). Children’s self-report of postoperative pain intensity and treatment threshold: Determining the adequacy of medication. Clinical Journal of Pain, 14, 116 – 120. Goodenough, B., Thomas, W., Champion, G. D., Perrott, D., Taplin, J. E., von Baeyer, C. L., et al. (1999). Unravelling age effects and sex differences in needle pain: Ratings of sensory intensity and unpleasantness of venipuncture pain by children and their parents. Pain, 80, 179 – 190. Jensen, M. P., Chen, C., & Brugger, A. M. (2003). Interpretation of visual analog scale ratings and change scores:
A reanalysis of two clinical trials of postoperative pain. Journal of Pain, 4, 407 – 414. Kalso, E., Pfyhi7, R., Onnela, P., Linko, K., Tigerstedt, I., & Tammisto, T. (1991). Intravenous morphine and oxycodone for pain after abdominal surgery. Acta Anaesthesiologica Scandinavica, 35, 642 – 646. Logan, D. E., & Rose, J. B. (2004). Gender differences in postoperative pain and patient controlled. Analgesia use among adolescent surgical patients. Pain, 109, 481– 487. Maunuksela, E.-L., Olkkola, K. T., & Korpela, R. (1987). Measurement of pain in children with self-reporting and behavioural assessment. Clinical Pharmacology and Therapeutics, 42, 137 – 141. McGrath, P. J., Cunningham, S. J., Goodman, J. T., & Unruh, A. (1986). The clinical measurement of pain in children: A review. Clinical Journal of Pain, 221 – 227. McGrath, P. J., & Unruh, A. M. (1999). Measurement and assessment of paediatric pain. In E. D. Wall, R. Melzack, (Eds.) Textbook of pain, 4th ed. (pp. 371 – 394). Edingburgh: Churchill Livingstone. Rosseland, L. A., & Stubhaug, A. (2004). Gender is confounding factor in pain trials: Women report more pain than men after arthroscopic surgery. Pain, 112, 248 – 253. Taenzer, A. H., Clark, C., & Curry, C. S. (2000). Gender affects report of pain and function after arthroscopic anterior cruciate ligament reconstruction. Anesthesiology, 93, 670 – 675. Tigerstedt, I., & Tammisto, T. (1988). A modified visual analog scale (VAS) for evaluation of pain intensity during immediate postoperative recovery. Schmerz Pain Doleur, 9, 27 – 31.