COMFORT behaviour scale and skin conductance activity: what are they really measuring?

AIM: To assess how efficiently the COMFORT behaviour scale measures acute pain in neonates, in comparison with skin conductance activity, a validated measure of pain and stress.
METHODS: Images of 36 newborns were analysed before, during and after painful heel pricks to measure glucose levels and compared with skin conductance activity variables.
RESULTS: Scale indicators and skin conductance variables were sensitive to changes in the periods 'during-before' and 'during-after' (Wilcoxon's test, p < 0.01). Significant values were found between all scale indicators and number of waves for Kendall's coefficient (p < 0.05), although responses differed when it came to how long they took to increase and correlations varied from fair to moderate (r < 0.6). Facial tension was more closely related to 15 sec after the painful event, while crying and calmness were more closely related to the later intervals (30 and 180 sec).
CONCLUSION: All scale indicators were related to skin conductance activity in all periods, indicating pain perception. Facial tension was the most efficient indicator, while others varied in performance after painful events and possibly indicated stress after trauma. These results are discussed from a phenomenological approach and in an anxiety paradigm. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.