Parallel assessment of prolonged neonatal distress by empathy-based and item-based scales

Objective: To evaluate the association between the empathy-based Faces Pain Scale-Revised (FPS-R) and the item-based Neonatal Pain, Agitation and Sedation Scale (N-PASS) when used to assess prolonged distress in term and preterm infants.

Method: Sequential prospective psychometric evaluations of distress, at 4-h intervals during a 48-h time period. FPS-R and N-PASS were employed in parallel by the nurses in charge in 44 term and preterm newborn infants.

Results: During the overall 48-h observation period, median FPS-R declined from 6/10 to 2/10 (p<0.001) while N-PASS did not change significantly. FPS-R and N-PASS showed strong correlation during the first 12h of observation (R(s)=0.786, p<0.001). During each of the following 12-h observation periods, the strength of this association decreased (12-24h: R(s)=0.781; 24-36 h: R(s)=0.675; 36-48 h: R(s)=0.658) while remaining significant (p<0.001). However, when used to categorize infants as being in distress or not, the rate of agreement between FPS-R and N-PASS showed little variation (0-12h: 79.6%, 12-24h: 88.6%; 24-36 h: 89.4%, 36-48 h: 84.9%).

Conclusions: In newborn infants serially assessed over 48 h, there is a progressive divergence between FPS-R and N-PASS. There is, however, reason to extend the use of the FPS-R also to the neonatal arena, as the rate of agreement between N-PASS and FPS-R to categorize an infant as being in distress or not remains stable. Preference of item- or empathy-based assessment may be a question of personal philosophy rather than medical science.