A COMPARISON OF 2 MEASURES OF FACIAL ACTIVITY DURING PAIN IN THE NEWBORN CHILD

Facial activity is strikingly visible in infants reacting to noxious e vents. Two measures that reduce this activity to composite events, the Neonatal Facial Coding System (NFCS) and the Facial Action Coding Sys tem (FACS), were used to examine facial expressions of 56 neonates res ponding to routine heel lancing for blood sampling purposes. The NFCS focuses upon a limited subset of all possible facial actions that had been identified previously as responsive to painful events, whereas th e FACS is a comprehensive system that is inclusive of all facial actio ns. Descriptions of the facial expressions obtained from the two measu rement systems were very similar, supporting the convergent validity o f the shorter, more readily applied system. As well, the cluster of fa cial activity associated with pain in this sample, using either measur e, was similar to the cluster of facial activity associated with pain in adults and other newborns, both full-term and preterm, providing co nstruct validity for the position that the face encodes painful distre ss in infants and adults.