The consideration of individual contextual factors in neonatal pain assessment : validation and revision of the Bernese Pain Scale for Neonates

Neonates are dependent on a caregiver to discover that they are in pain and to manage it. Numerous pain assessment scales have been developed, but pain assessment is challenging because neonates of different gestational ages (GAs) have widely varied pain responses. Individual contextual factors such as GA or health status may account for this variability in pain response. The aim of the present dissertation was the validation and revision of the Bernese Pain Scale for Neonates (BPSN) by testing its psychometric properties and analyzing the influence of individual contextual factors on the variability in pain response. The BPSN is a pain assessment tool that is widely used in Swiss neonatal intensive care units. In this prospective multisite validation study, 154 neonates between 24 2/7 and 41 4/7 weeks of gestation were videotaped during 1-5 routine capillary heel sticks in their first 14 days of life. For each heel stick, three video sequences were produced: baseline, heel stick, and recovery. Comprehensive psychometric testing was conducted to examine the BPSN’s underlying factor structure, interrater reliability, concurrent and construct validity, sensitivity and specificity. Single and multiple linear mixed effects analyses were used to examine the influence of individual contextual factors on variability in pain response. The results of the psychometric testing indicated a significant reduction of the scale from nine to four items: crying, facial expression, posture and heart rate. This modified BPSN showed promising reliability and validity, especially when the cut-off that discriminates between no or low pain and moderate to severe pain is adjusted to increase with increasing GA. Apart from the GA, baseline behavioral state and ventilation status were the individual contextual factors which the revised BPSN should account for. The BPSN-Revised is a promising tool for acute procedural pain assessment in full-term and preterm neonates with different GAs. Future studies should test its validity, feasibility and clinical utility.