Exploration and Validation of Behavioral Pain Measures and Physiological Pain Measures Factor Structure Extracted From the Pain Assessment Tool Item Scores for Infants Admitted to Neonatal Intensive Care

Abstract

Objective: The objective of the study was to explore and then validate the factor structure of the Pain Assessment Tool (PAT). Materials and Methods:A retrospective medical record review was performed of all infants who were admitted to a neonatal intensive care unit between 2008 and 2018 and had 1 PAT assessment (n = 2111). Scores on items of the PAT were collected. Infants were randomized to either the principal component analysis (n = 1100) to explore the factor structure or confirmatory factor analysis (n = 1011).Results: Infants in the 2 samples were demographically comparable. A 2-factor model, consisting of factors Behavioral and Physiological Pain Measures, was extracted, explaining 39.8% of the total variance. There was a low interfactor correlation (r = 0.12), and both Behavioral (r = 0.59) and Physiological Pain (r = 0.37) Measures factor scores were correlated with nurses' perception of pain scores. When the frequencies in the gestational age at birth categories were compared between upper and lower quartile score infants, there was more with pain at preterm than at term (χ 2 (3) = 44.9, P < 0.001) for the Physiological Pain Measures factor, whereas Behavioral Pain Measures frequency was higher at term than at preterm (χ 2 (3) = 8.1, P < 0.043). A similar pattern was observed for postmenstrual age at assessment categories: Behavioral Pain Measures (χ 2 (3) = 41.8, P < 0.001) Physiological Pain Measures (χ 2 (3) = 46.1, P < 0.001). The 2-factor correlated model performed better at explaining the observed variances: (χ 2 (13) = 41.6, P < 0.001) compared with rival models.Discussion: The PAT assesses both Behavioral Pain and Physiological Pain Measures, and these dimensions need to be considered separately when assessing pain in infants in the neonatal intensive care unit. Behavioral item scores may be insufficient for detecting pain in premature infants if used alone.

Neonatal pain assessment: Do we have the right tools?

“…The identified studies assess several internationally used, pain assessment instruments including ALPS-Neo ( 3 ), BPSN ( 10 , 11 ),CHIPPS ( 10 ), COMFORT-B/neo ( 1 ), COVERS ( 15 ), EDIN ( 3 )/EDIN6 ( 7 ), NFCS-R ( 10 ), NIAPAS ( 16 ), NIPE ( 17 , 18 ), NIPS ( 4 , 10 ), N-PASS ( 1 , 4 , 10 , 16 ), PAT ( 13 15 ), and PIPP-R ( 2 , 10 , 16 , 19 ). The tools assessed had varying results in correspondence to the eight categories upon which they were evaluated ( Table 2 ).…”

“…PIPP-R is revised by scoring the contextual factors (gestational age and behavioral state) only if there is a change in behavioral and physiologic factors after the painful event ( 12 ). Researchers found that the PIPP-R was proficient in measuring behavioral and physiological parameters, distinguished distress and pain, and could measure continuous, chronic, and acute pain, but lacked inter-rater reliability and presumed that because low gestational age infants could not express pain, that they did not feel pain ( 13 , 16 ).…”

“…Another study compared the usage of EDIN and EDIN6, where it was determined that EDIN6 pain assessment readings were 3 times greater than that of EDIN ( 7 ). One study evaluated the effectiveness of PIPP-R, N-PASS, and NIAPAS in a 60-bed NICU in China ( 13 ) and reported that all three scales were correlated with one another, with 55.9% of nurses giving preference to N-PASS, and 23.5% and 20.6% to NIAPAS and PIPP-R respectively, making N-PASS the most feasible and functional amongst the three pain assessment tools evaluated ( 13 ).…”

“…One barrier to the development of a standardized pain assessment tool is age-dependent variation in pain response. For example, preterm infants may lack the motor skills to express pain compared to a full-term infant ( 1 , 7 , 13 ). Another barrier to the standardization of pain assessment tools is the non-specific nature of pain symptoms, for example crying can indicate hunger, the need to be held, agitation, or a soiled diaper in addition to pain ( 4 ).…”

Comparison of Pain Score in Patients with Brain Disorders Using Care Pain Observation Tool (CPOT) and Nonverbal Pain Scale (NVPS)

“…Nevertheless, in unconscious patients, pain assessment depends on the skills of the medical staff, especially nurses, and the type and validity of the instrument. Behavioral Pain Scale, Critical Care Pain Observation Tool (CPOT), and Nonverbal Pain Scale (NVPS) are some of the tools used to assess pain in unconscious patients (10,11).…”