A FUNCTIONAL ANALYSIS OF THE WONG-BAKER AND FPS-R FACES PAIN SCALES: MAKING GROUND FOR DEVELOPMENTALLY-BASED METRICS
The developmental suitability of facial pain scales for children below 8-years-old has been under question. This study assumes that any valuable pain metrics is at least interval level. It uses integration tasks and FM methodology to examine how children of 6-7 years-old integrate pain related information. In one experiment, the WB and the FPS-R pain scales were taken as factors, with their constituent faces as levels, in a factorial design. Participants were presented with pairs of faces (one from each scale), said to represent the pain of two children, and evaluated the overall amount of pain in each pair. Virtually every child used an extremity weighting averaging rule for the integration. In two further experiments, inner features (eyes, eyebrows, mouth) of the hand drawn faces composing each scale were used as factors (varied along three levels). For most children, these features were integrated according to an averaging rule.