Does the Neonatal Facial Coding System Differentiate Between Infants Experiencing Pain-Related and Non-Pain-Related Distress?

The Neonatal Facial Coding System (NFCS) is widely accepted as a measure of infant pain-related distress in known pain-specific contexts. It has clearly shown the ability to distinguish between facial reactivity in no-pain and pain-related situations. The primary purpose of this study was to explore whether NFCS differentiates between pain-related and non-pain-related distress. Two groups of 35 infants (1 group was distressed before injection whereas the other group was not distressed before injection) were coded using NFCS before and after an immunization procedure. Within-group analyses of infants who were distressed before immunization suggested that NFCS was not able to discriminate between pain-related and non-pain-related distress. However, between-group analyses showed NFCS discriminated between potential gradations of distress in infants after immunization. Results suggest that NFCS has the ability to discriminate between intensities of distress but not between pain-related and non-pain-related distress. Perspective: Adding to the NFCS validity literature, this study suggests that while able to distinguish between no-distress and pain-related distress, facial actions of NFCS may not distinguish between pain-related and non-pain-related distress expressions. However, NFCS was able to discern infants presumed to have higher pain-related distress due to experiencing pre-needle distress. (c) 2009 by the American Pain Society