Behavioral and physiological pain structures of PIPP-R and parental stress: structural equation modeling approach

Abstract

Background: Although most non-acute pain assessment tools are multi-dimensional (behavioral and physiological measures) in their approach, the outputs of such tools are considered unidimensional. This study aimed to explore and determine the behavioral and physiological pain structures of Premature Infant Pain Profile-Revised (PIPP-R) for neonates and its association with parental stress. Methods: This cross-sectional study was conducted in 2022-2023 in Isfahan, Iran. We recruited 400 pre-term infants, i.e. with gestational age (GA) of less than 37weeks who were admitted to the NICU of educational hospitals. PIPP-R and Parental Stressor Scale: Neonatal Intensive Care Unit (PSS: NICU) were used for data gathering. The latent structures of pain and its association with parental stress were explored using latent variable modeling approach. Results: A two-factor model, i.e. behavioral and physiological pain factors, was extracted, explaining 65 of the total variance. The results of confirmatory factor analysis showed that the identified structures in the exploratory factor analysis could be nearly replicated (CFI = 0.99, TLI = 0.98, RMSEA = 0.001). Behavioral pain structure, independent from gestational age had a significant direct association with parental stress score (beta = 0.005, SE = 0.002, p = 0.026). Conclusions: The PIPP-R assesses both behavioral and physiological pain factors. We also found that behavioral pain factor was associated with parental stress.