Weak evidence behind how we measure pain in babies

(Press-News.org) A newly-published Cochrane review reveals significant gaps in the clinical rating scales used to assess pain in newborn babies, highlighting the urgent need for improved tools and global collaboration.

Despite the critical importance of accurately measuring pain in newborns, the review found that none of the available scales are backed by the high-quality evidence and methodological safeguards required to confirm their validity and reliability in clinical practice.

Neonatal pain assessment and management presents a challenge for clinical staff worldwide. Over 40 rating scales have been developed and adapted worldwide assessing different parameters and various types of pain.

Six to nine percent of all newborns require admission to a neonatal intensive care unit (NICU) due to either illness of prematurity. These infants endure multiple painful procedures daily, which can lead to long-term negative effects. Due to this, valid tools to support the assessment of pain are of great importance.

Infant pain scales lack robust evidence

The Cochrane review analysed 79 studies involving over 7,000 infants across 26 countries, evaluating 27 different clinical rating scales. All rating scales were found to be supported by very low-quality evidence, indicating major limitations in their effectiveness and clinical applicability.

“Over 70% of rating scales in this review did not assess content and structural validity, and both these factors are essential when selecting a measurement instrument,” says Kenneth  Färnqvist, physiotherapist and PhD candidate at the Department of Molecular Medicine and Surgery at the Karolinska Institute in Sweden. “Without a strong foundation in these areas, other necessary measures, such as reliability, cannot be accurately evaluated. Future studies must prioritise rigorous validation to improve neonatal pain assessment.”

Measuring pain in newborns is particularly complex compared to adults. Such limitations may lead to an over- or under-estimation of pain, resulting in unnecessary sedation or inadequately treated pain, potentially jeopardising infant safety through treatment side-effects, including withdrawal symptoms or prolonged discomfort. Premature infants further complicate matters, as they often have a reduced ability to display robust pain behaviour due to their immaturity. The same is also true for ill or sedated infants.

“It is important to remember that clinical rating scales are only surrogates for pain measurement,” says Roger F. Soll, Professor of Neonatology at the University of Vermont. “Given the uncertainty highlighted in this review, clinical staff should avoid relying too heavily on the rating scales currently in practice and instead strive to decrease painful procedures as much as possible in this vulnerable population.”

Global collaboration needed to improve infant pain assessment

Despite the disappointing results, this review presents an opportunity for progress in neonatal pain assessment, particularly through global collaboration and innovation.

Emma Persad, doctor and PhD candidate at the Department of Women’s and Children’s Health at the Karolinska Institute, sees this as an opportunity for global collaboration and a call to action.

“This is our chance to unite clinicians and methodologists in developing a rigorously validated scale from scratch, one that meets all necessary checks before implementation in research and practice,” Emma says. “We look forward to beginning this impactful work and the implications it will have on assessing and managing neonatal pain worldwide.”

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