Authors:
Lynn B. Clutter, MSN,
RNC
Kristie Nix, EdD, RN
Donna L. Wong, PhD, RN, CPN, PNP, FAAN
Traditionally, pediatric pain has been inadequately treated. One reason for this problem has been the difficulty in assessing pain in young children. Since the most valid measure of pain is self-report, several instruments have been developed to help children describe how much they are hurting. The use of cartoon faces, such as the Wong-Baker FACES Pain Rating Scale, provides a simple method for measuring pain in children as young as 3 years of age.
A previous study showed that there were no significant differences in 4- and 5- year old children's rating of injection pain using the original FACES's instructions, which include affective words (happy, sad, feeling), and a revised set without the affective words. The findings support the ability of the instrument to measure pain intensity. In addition to use of the original instructions, health professionals may at times use minimal explanation. However, there is no data to support the validity of the FACES using abbreviated instructions.
Health professionals, particularly nurses, need simple, quick, reliable, and valid methods of assessing pain in children. The FACES has demonstrated validity, reliability, and children's, parents', and nurses' preference for the tool among other scales with its original instructions for measuring pain intensity in children from 3 to 18 years and in adults. This study was intended to provide evidence for an even simpler, quicker way to use the scale and offer additional data for construct validity of the FACES.
This study investigated the influence of two types of instruction, the original set and an abbreviated set, on children's ability to use the FACES to rate injection pain. To provide additional evidence of the instrument's construct validity, the two sets of instructions were used pre- and post- injection with children 4 and 5 years of age.
A convenience sample of 150 English-speaking children ages 4 and 5 years was used. The children were receiving parenteral immunizations at 5 city/county health department immunization clinic sites in Tulsa, Oklahoma.
The study used an experimental design with subjects randomly assigned by coin toss to Group 1 (original instructions) or Group 2 (abbreviated instructions). Group 2 abbreviated instructions are in two parts: Part A. These FACES show how much hurt you have now (point to FACES). How much hurt do you have now? Pause for response; if none, say part B: Point to FACE 1 and say, "This FACE has no hurt." Slide your finger to FACE 5 and say, "This FACE hurts as much as you can imagine, although you don't have to be crying to feel this bad. Choose the face that best describes how you are feeling."
After the instructions were given, the child responded with an immediate, pre-injection pain rating. After receiving one or more immunization injections, the child gave a post-injection pain rating.
Using the binomial approximation to the normal distribution the following were found to be significant at the 95% confidence interval: 1) difference in the proportions that require further explanation between Group 1 and Group 2; with Group 2 requiring more explanation; 2) difference in the mean pre-scores for the two groups; 3) difference in the proportion giving non-zero pre-scores between Group 1 and Group 2 with a greater number of non-zero scores in Group 2.
Based on the t-test analysis, the difference between the mean pre-scores and mean post-scores were significant for both instruction groups (p<.05). However, in Group 1, there were two pre-scores reported as greater than the post-scores, and in Group 2, five such scores; the difference was not significant. Linear correlation analysis on age and pain scores revealed no significant relationships in either group.
The results support the known-groups construct validity for both sets of instructions, in that they differentiated between the pain rating before and after application of the stimulus. However, the instructions yielded different pain intensity scores. The difference was most obvious in the pre-score rating. Based on these findings, it is recommended that the original instructions for the FACES be used with children 4 and 5 years old. Additional research is needed to determine the influence of abbreviated instructions with older children. Since validity of the tool for measuring pain intensity was supported with 4 and 5 year olds, its clinical use in the assessment of pain is recommended.
(Unpublished, 1995)
March 15, 2002
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