Search

Diverse behavioral cues have been proposed to be useful cues in infant pain assessment, but there is a paucity of evidence on the basis of formal psychometric evaluation to establish their validity for this purpose. We aimed to examine 2 widely used coding systems, the Neonatal Facial Coding System (NFCS) and the Modified Behavior Pain Scale (MBPS), by examining their factor structures with confirmatory factor analysis using a large archival data set. The results indicated that an item-reduced NFCS scale with 3 items produced a 1-factor pain model that maintained the good psychometric properties of the 7-item scale. In addition, it was found that MBPS also has challenging internal consistency, with items that are weakly correlated as well as highly redundant. One item of the MBPS may be able to capture the construct of pain equally well or potentially improve its psychometric properties. Redefinition of the MBPS with cry as a sole indicator was suggested. This analysis provides 2 new iterations of the NFCS and MBPS that improve construct validity and internal consistency. These shorter versions also improve the feasibility of both measures and increase their potential for clinical use because less time is required for their administration., Perspective: This article presents new iterations of the NFCS and MBPS scales. These revised measures improve the internal consistency of the measures, feasibility of use of the tools in research settings, and the efficiency of the coding process. The revised tools could also improve the feasibility of coding within clinical settings., (Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.)

Objective pain assessment is required for appropriate pain management in the clinical setting. However, clinical gold standard pain assessment is based on subjective methods. Automated pain detection from physiological data may provide important objective information to better standardize pain assessment. Specifically, electrodermal activity (EDA) can identify features of stress and anxiety induced by varying pain levels. However, notable variability in EDA measurement exists and research to date has demonstrated sensitivity but lack of specificity in pain assessment. In this paper, we use timescale decomposition (TSD) to extract salient features from EDA signals to identify an accurate and automated EDA pain detection algorithm to sensitively and specifically distinguish pain from no-pain conditions.

Some pain behaviors appear to be automatic, reflexive manifestations of pain, whereas others present as voluntarily controlled. This project examined whether this distinction would characterize pain cues used in observational pain measures for children aged 4-12. To develop a comprehensive list of cues, a systematic literature search of studies describing development of children's observational pain assessment tools was conducted using MEDLINE, PsycINFO, and Web of Science. Twenty-one articles satisfied the criteria. A total of 66 nonredundant pain behavior items were identified. To determine whether items would be perceived as automatic or controlled, 277 research participants rated each on multiple scales associated with the distinction. Factor analyses yielded three major factors: the "Automatic" factor included items related to facial expression, paralinguistics, and consolability; the "Controlled" factor included items related to intentional movements, verbalizations, and social actions; and the "Ambiguous" factor included items related to voluntary facial expressions. Pain behaviors in observational pain scales for children can be characterized as automatic, controlled, and ambiguous, supporting a dual-processing, neuroregulatory model of pain expression. These dimensions would be expected to influence judgments of the nature and severity of pain being experienced and the extent to which the child is attempting to control the social environment., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

Background: Current pain assessment methods in youth are suboptimal and vulnerable to bias and underrecognition of clinical pain. Facial expressions are a sensitive, specific biomarker of the presence and severity of pain, and computer vision (CV) and machine-learning (ML) techniques enable reliable, valid measurement of pain-related facial expressions from video. We developed and evaluated a CVML approach to measure pain-related facial expressions for automated pain assessment in youth., Methods: A CVML-based model for assessment of pediatric postoperative pain was developed from videos of 50 neurotypical youth 5 to 18 years old in both endogenous/ongoing and exogenous/transient pain conditions after laparoscopic appendectomy. Model accuracy was assessed for self-reported pain ratings in children and time since surgery, and compared with by-proxy parent and nurse estimates of observed pain in youth., Results: Model detection of pain versus no-pain demonstrated good-to-excellent accuracy (Area under the receiver operating characteristic curve 0.84-0.94) in both ongoing and transient pain conditions. Model detection of pain severity demonstrated moderate-to-strong correlations (r = 0.65-0.86 within; r = 0.47-0.61 across subjects) for both pain conditions. The model performed equivalently to nurses but not as well as parents in detecting pain versus no-pain conditions, but performed equivalently to parents in estimating pain severity. Nurses were more likely than the model to underestimate youth self-reported pain ratings. Demographic factors did not affect model performance., Conclusions: CVML pain assessment models derived from automatic facial expression measurements demonstrated good-to-excellent accuracy in binary pain classifications, strong correlations with patient self-reported pain ratings, and parent-equivalent estimation of children's pain levels over typical pain trajectories in youth after appendectomy., (Copyright © 2015 by the American Academy of Pediatrics.)

Objectives: Assessing pain in young children requires astute judgment by observers. Multidimensional observational scales for pediatric pain contribute by providing behavioral cues believed to characterize pain in children; yet, few measurement items have undergone rigorous psychometric evaluation. This is the case with facial expression, which has been widely recognized as the most sensitive and specific nonverbal indicator of pain. The criteria for identifying facial expressions of pain differ substantially across scales and are frequently inconsistent with empirical descriptions., Materials and Methods: The present study compared observer ratings of children's (aged 1 to 6 y, inclusive) videotaped postoperative pain reactions using the facial activity items from 6 widely used pediatric pain assessment scales and an anatomically based and empirically validated measure, the Child Facial Coding System. We hypothesized that facial expression items that did not correspond to empirical descriptions would lead to less reliable and divergent pain estimates. Intercoder reliability, criterion validity (empirical and convergent), content validity, and face validity were examined., Results: Findings supported hypotheses and indicated that variation in cues proposed for assessing facial expression led to widely ranging scores that could be insensitive to differences in children's pain intensity., Discussion: The facial items varied considerably in coder judgment reliability as well as criterion (empirical and convergent), content, and face validity. Observational scales should provide behavioral cues that correspond to empirical descriptions of the facial expression of pain.

Chronic pain is highly prevalent in the ageing population. Individuals with neurological disorders such as dementia are susceptible patient groups in which pain is frequently under-recognised, underestimated, and undertreated. Results from neurophysiological and neuroimaging studies showing that elderly adults are particularly susceptible to the negative effects of pain are of additional concern. The inability to successfully communicate pain in severe dementia is a major barrier to effective treatment. The systematic study of facial expressions through a computerised system has identified core features that are highly specific to the experience of pain, with potential future effects on assessment practices in people with dementia. Various observational-behavioural pain assessment instruments have been reported to be both reliable and valid in individuals with dementia. These techniques need to be interpreted in the context of observer bias, contextual variables, and the overall state of the individual's health and wellbeing., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Unlabelled: Major efforts to develop objective measurement tools for neonatal pain assessment have been made. However, the challenge of measuring pain in neonates remains suggesting that contextual factors (cFs) might alter their responses to pain. Although the role of cFs is increasingly discussed as crucial for pain assessment, they are not well described in the literature and are rarely considered in the clinical setting despite their importance., Aim: To systematically examine studies investigating the impact of cFs on pain response in preterm infants., Method: A literature search was undertaken for the period from 1990 to 2009. Studies reporting the relation between one or more cFs and pain response in preterm infants during a heelstick procedure were considered for inclusion., Results: Twenty-three studies satisfied inclusion criteria. The studies varied relative to their design, sample, analysis procedures, and variables examined. Six categories of cFs emerged: age, pain exposure, health status, therapeutic interventions, behavioral status, and demographic factors. The examined cFs varied in the strength of their association with pain response, although none were invariably related, as evidenced by contradictory findings. In some cases the inconsistencies appeared attributable to methodological limitations in studies. Behavioral and physiological pain responses were not always in agreement as would be expected., Conclusion: This review supports the influence of some cFs on pain response. However, the results remain inconclusive which may be, in part, related to the heterogeneity of the studies. Contextual factors need further investigation for a better understanding of the magnitude of their effect on pain response., (Copyright © 2011 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.)

Pain assessment conventionally has been viewed hierarchically with self-report as its "gold-standard." Recent attempts to improve pain management have focused on the importance of assessment, for example, the initiative to include pain as the "fifth vital sign." We question the focus in the conceptualization of pain assessment upon a "vital sign," not in terms of the importance of assessment, but in terms of the application of self-report as a mechanistic index akin to a biologic measure such as heart rate and blood pressure. We synthesize current inclusive models of pain and pain assessment and propose a more comprehensive conceptualization of pain assessment as a transaction based on an organismic interplay between the patient and clinician.

Facial expression is widely used as a measure of pain in infants; whether nonhuman animals display such pain expressions has never been systematically assessed. We developed the mouse grimace scale (MGS), a standardized behavioral coding system with high accuracy and reliability; assays involving noxious stimuli of moderate duration are accompanied by facial expressions of pain. This measure of spontaneously emitted pain may provide insight into the subjective pain experience of mice.

Unlabelled: Recent developments in clinical, cognitive, and behavioral sciences as well as in social neuroscience can provide new perspectives on our understanding of different forms of pain expression and the social reactions of observers to various types of pain expression. Studies indicate that pain expression is governed by both automatic (unintentional, reflexive) and controlled (intentional, purposive) neuroregulatory systems. Reciprocal mechanisms in observers responsible for automatic (unintentional, reflexive) and controlled (intentional, reflective) reactions also are important. Observers appear more likely to display immediate "visceral" emotional reactions to unintentional, reflexive expression, whereas controlled expression characterized by purposive behavior appears more likely to elicit reflection on the nature and origins of the person's pain. This review summarizes research within the context of a theoretical model for understanding how pain is perceived in others., Perspective: People attempting to understand another person's pain may have access to the person's spontaneous behavioral reaction as well as verbal report and other purposive communications. The former instigates reflexive and emotional reactions, whereas the latter tends to be perceived as confounding expression of experience with response to situational demands., (Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Background: Research suggests that caregivers' beliefs pertaining to infant pain and which infant pain cues are perceived to be important play an integral role in pediatric pain assessment and management., Objectives: Following a recent quasi-experimental study reporting on caregiver background and age differences in actual infant pain judgments, the present study clarified these findings by analyzing caregivers' pain beliefs and the cues they use to make pain assessments, and by examining how the wording of belief questions influenced caregivers' responses., Methods: After making pain judgments based on video footage of infants between two and 18 months of age receiving immunizations, parents, nurses and pediatricians were required to respond to questionnaires regarding pain beliefs and importance of cues., Results: Parents generally differed from pediatricians. Parents tended to have less optimal beliefs regarding medicating the youngest infants, were more influenced by question wording, and reported using many more cues when judging older infants than other caregiver groups. In terms of beliefs, influence of question wording and cue use, nurses tended to fall in between both groups; they displayed similarities to both parents and pediatricians., Conclusions: Paralleling the original findings on pain judgments, these findings suggest that parents differ from pediatricians in their pain beliefs and the cues they use to make pain judgments. Moreover, some similarities were found between parents and nurses, and between nurses and pediatricians. Finally, caution must be taken when interpreting research pertaining to beliefs about infant pain because question wording appears to influence interpretation.

The biasing effect of pain sensitivity information and the impact of facial activity on observers' judgements of pain intensity of children with autism were examined. Observers received information that pain experience in children with autism is either the same as, more intense than, or less intense than children without autism. After viewing six video clips of children with autism undergoing venepuncture, observers estimated pain intensity using a visual analogue scale. Facial activity as coded by Chambers et al. (Child Facial Action Coding System Revised Manual, 1996) had a significant impact on observers' estimates of pain intensity; pain sensitivity information did not. These results have important implications for the assessment and management of pain in children with autism.

This paper represents an expert-based consensus statement on pain assessment among older adults. It is intended to provide recommendations that will be useful for both researchers and clinicians. Contributors were identified based on literature prominence and with the aim of achieving a broad representation of disciplines. Recommendations are provided regarding the physical examination and the assessment of pain using self-report and observational methods (suitable for seniors with dementia). In addition, recommendations are provided regarding the assessment of the physical and emotional functioning of older adults experiencing pain. The literature underlying the consensus recommendations is reviewed. Multiple revisions led to final reviews of 2 complete drafts before consensus was reached.

Accurate pain assessment is the foundation for effective pain management in children. At present, there is no clear consensus regarding the age at which young children are able to appropriately use self-report scales for pain. This study examined young children's ability to use the Faces Pain Scale-Revised; (FPS-R; [Hicks CL, von Baeyer CL, Spafford PA, van Korlaar I, Goodenough B. The Faces Pain Scale-Revised: toward a common metric in pediatric pain measurement. Pain 2001; 93: 173-83]) for pain in response to vignettes and investigated the role of developmental factors in predicting their ability to use the scale. One hundred and twelve healthy children (3-6 years old) were assessed for their ability to accurately use a common faces scale to rate pain in hypothetical vignettes depicting pain scenarios common in childhood. Accuracy was determined by considering whether children's judgements of pain severity matched the pain severity depicted in the various vignettes. Children were also administered measures of numerical reasoning, language, and overall cognitive development. Results indicated that 5- and 6-year-old children were significantly more accurate in their use of the FPS-R in response to the vignettes than 4-year-old children, who in turn were significantly more accurate than 3-year-old children. However, over half of the 6-year-olds demonstrated difficulties using the FPS-R in response to the vignettes. Child age was the only significant predictor of children's ability to use the scale in response to the vignettes. Thus, a substantial number of young children experienced difficulties using the FPS-R when rating pain in hypothetical vignettes, although the ability to use the scale did improve with age.

Objectives: Although self-reports are a commonly used means of assessing pain in clinical settings, little is understood about the nature of children's spontaneous verbal expressions of pain. The purpose of this study was to describe verbalizations of pain among children receiving a preschool immunization and to examine how pain verbalizations correspond to children's facial expressions and self-reports of pain intensity., Methods: Fifty-eight children between the ages of 4 years 8 months and 6 years 3 months (67% female) were videotaped while receiving their routine preschool immunization. Global ratings of facial expression and detailed transcription and coding of pain verbalizations were undertaken. Children provided self-reports of pain using a 7-point faces pain scale., Results: Fifty-three percent of children used verbalizations spontaneously to express their pain. The modal verbalization was the interjection "Ow!," which expressed negative affect and was specific to the experience of pain. Older children were less likely to use verbalizations to express their pain. Children who used verbalizations to express pain displayed greater facial reactions to pain and rated their pain experience as being more intense than children who did not use words to express their pain., Discussion: Results indicate that many young children do not spontaneously use verbalizations to express pain from immunization. When 5-year-olds use verbalizations to express pain, the verbalizations are most often brief statements that express negative affect and directly pertain to pain. Knowledge of how children verbalize pain may lead to an improved ability to assess and manage pediatric pain.

Objectives: Faces scales are commonly used to obtain self-reports of pain intensity from children. Previous research using hypothetical vignettes and pain following venepuncture has found differences in children's pain ratings as a function of the type of faces scale used. The purpose of the present study was to determine whether scales beginning with a smiling rather than neutral "no pain" face would produce higher ratings in the assessment of postoperative pain intensity in children and to compare ratings using different faces scales to those reported with an additional independent measure of pain intensity., Methods: Participants were 78 children between the ages of 5 and 13 years undergoing surgery, one of their parents, and their postoperative care nurse. Following surgery, children were asked to provide a rating of their current pain intensity using a set of 5 successively administered faces scales and the Colored Analog Scale (CAS). Parents and nurses provided independent ratings using the same measures., Results: Results showed that parents and nurses rated significantly more pain when using scales with a smiling rather than a neutral "no pain" face. This pattern was not as clear for the children's ratings, although their highest ratings were provided when using a smiling "no pain" faces scale. Children's and nurses' ratings on the CAS were generally more similar to their ratings using scales with neutral "no pain" faces, whereas parents' CAS ratings tended to fall in between ratings provided on the smiling and neutral "no pain" faces scales. Scale preference, age and sex differences in pain ratings, and child-parent-nurse agreement in pain ratings are also examined., Discussion: Children's and parents' ratings of postoperative pain intensity are influenced by the presence of a smiling "no pain" face at the beginning of faces scales, with such scales producing significantly higher ratings than scales with neutral "no pain" faces. Ratings on the independent CAS measure were more comparable to those provided on faces scales with neutral "no pain" faces. Nurses are also susceptible to the influencing effect of a smiling face at the beginning of a faces scale.

Clinicians tend to assign greater weight to non-verbal expression than to patients' self-report when judging the location and severity of pain. Judgments can misrepresent the actual experience because patients can successfully alter their pain expressions. The present research provides a basis for discriminating genuine and deceptive pain expressions by expanding detailed accounts of facial expressions to include previously unexamined variables, including study of temporal patterns and contiguity of facial actions as well as the occurrence of specific deception cues. Low back patients' facial expressions (n=40) were videotaped at rest and while undergoing a painful straight leg raise with instructions to: (1) genuinely express their pain, or (2) pretend that it did not hurt. As well, they were asked to fake pain without moving. The Facial Action Coding System was used to describe and quantify facial activity. The different types of expression were compared on the frequency, type, intensity, temporal pattern and contiguity of facial actions, as well as on the frequency of specific deception cues. Findings confirmed the difficulty of discriminating the facial expressions, but indicated that faked pain expressions show a greater number of pain-related and non-pain-related actions, have a longer peak intensity and overall duration, and the facial actions observed tend to be less temporally contiguous than are those in genuine pain expressions. The differences between masked pain and neutral expressions were subtle, with a greater frequency of mouth opening and residual eyebrow movement in masked pain expressions. Thus, there is an empirical basis for discriminating genuine and deceptive facial displays.

The numerous pain rating scales using faces depicting varying degrees of distress to elicit reports of pain from children fall into two categories; those with a neutral face as the 'no pain' anchor, and those with a smiling face as the 'no pain' anchor. This study examined the potentially biasing impact of these anchor types on children's self-reports of pain in response to a series of vignettes. Participants were 100 children stratified by age (5-6 years, 7-8 years, 9-12 years) and randomly assigned to one of three groups: (1) neutral scale/sensory instructions; (2) smiling scale/sensory instructions; (3) smiling scale/affective instructions. Children completed a faces scale, a VAS, and emotions ratings in response to four scenarios depicting: (1) no pain/negative emotions; (2) pain/negative emotions; (3) no pain/positive emotions: (4) pain/positive emotions. Results showed that children who used the smiling scale had significantly higher pain scores for no pain and pain/negative emotions vignettes and significantly lower faces scale scores for pain/positive vignettes than children who used the neutral faces scale. Instructions varying in focus on sensory or affective qualities of pain had no effect on children's pain ratings. Group differences in children's ratings with the VAS and emotions measure suggested that rating pain with a smiling faces scale may alter a child's concept of pain. Age differences indicated the younger children rated the negative emotion vignettes as more painful than the older children. These findings suggest that children's pain ratings vary depending on the types of faces scale used, and that faces scales with smiling anchors may confound affective states with pain ratings.

Caretakers intuitively use various sources of evidence when judging infant pain, but the relative importance of salient cues has received little attention. This investigation examined the predictive significance for judgements of painful discomfort in preterm and full-term neonates of behavioural (facial activity and body movement), contextual (invasiveness of the procedure), and developmental (gestational age) information. Judges viewed videotapes showing infants varying in the foregoing characteristics undergoing heel incisions for routine blood sampling purposes. Findings indicated all but the contextual information contributed uniquely to judgements of pain, with facial activity accounting for the most unique variance (35%), followed by bodily activity and gestational age, each accounting for 3% and 1% of the judgmental variance, respectively. Generally, 71% of the variance in ratings of pain could be predicted using facial activity alone, compared to 30% of the variance using bodily activity alone, 19% by relying on context alone, and 8% by referring to gestational age alone. Noteworthy was the tendency to judge early preterm infants to be experiencing less pain even though they were subjected to the same invasive procedure as the older infants. This finding also runs counter to evidence from developmental neurobiology which indicates that preterm newborns may be hypersensitive to invasive procedures.

Objective pain assessment is required for appropriate pain management in the clinical setting. However, clinical gold standard pain assessment is based on subjective methods. Automated pain detection from physiological data may provide important objective information to better standardize pain assessment. Specifically, electrodermal activity (EDA) can identify features of stress and anxiety induced by varying pain levels. However, notable variability in EDA measurement exists and research to date has demonstrated sensitivity but lack of specificity in pain assessment. In this paper, we use timescale decomposition (TSD) to extract salient features from EDA signals to identify an accurate and automated EDA pain detection algorithm to sensitively and specifically distinguish pain from no-pain conditions.

Objective: Pain assessment in children continues to challenge clinicians and researchers, as subjective experiences of pain require inference through observable behaviors, both involuntary and deliberate. The presented approach supplements the subjective self-report-based method by fusing electrodermal activity (EDA) recordings with video facial expressions to develop an objective pain assessment metric. Such an approach is specifically important for assessing pain in children who are not capable of providing accurate self-pain reports, requiring nonverbal pain assessment. We demonstrate the performance of our approach using data recorded from children in post-operative recovery following laparoscopic appendectomy. We examined separately and combined the usefulness of EDA and video facial expression data as predictors of children's self-reports of pain following surgery through recovery. Findings indicate that EDA and facial expression data independently provide above chance sensitivities and specificities, but their fusion for classifying clinically significant pain vs. clinically nonsignificant pain achieved substantial improvement, yielding 90.91% accuracy, with 100% sensitivity and 81.82% specificity. The multimodal measures capitalize upon different features of the complex pain response. Thus, this paper presents both evidence for the utility of a weighted maximum likelihood algorithm as a novel feature selection method for EDA and video facial expression data and an accurate and objective automated classification algorithm capable ofdiscriminating clinically significant pain from clinically nonsignificant pain in children. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the letter "Bridging the Gap Between Pain Assessment and Treatment: Time for a New Theoretical Approach?" by T. Voepel-Lewis.

Analgesic trials pose unique scientific, ethical, and practical challenges in pediatrics. Participants in a scientific workshop sponsored by the US Food and Drug Administration developed consensus on aspects of pediatric analgesic clinical trial design. The standard parallel-placebo analgesic trial design commonly used for adults has ethical and practical difficulties in pediatrics, due to the likelihood of subjects experiencing pain for extended periods of time. Immediate-rescue designs using opioid-sparing, rather than pain scores, as a primary outcome measure have been successfully used in pediatric analgesic efficacy trials. These designs maintain some of the scientific benefits of blinding, with some ethical and practical advantages over traditional designs. Preferred outcome measures were recommended for each age group. Acute pain trials are feasible for children undergoing surgery. Pharmacodynamic responses to opioids, local anesthetics, acetaminophen, and nonsteroidal antiinflammatory drugs appear substantially mature by age 2 years. There is currently no clear evidence for analgesic efficacy of acetaminophen or nonsteroidal antiinflammatory drugs in neonates or infants younger than 3 months of age. Small sample designs, including cross-over trials and N of 1 trials, for particular pediatric chronic pain conditions and for studies of pain and irritability in pediatric palliative care should be considered. Pediatric analgesic trials can be improved by using innovative study designs and outcome measures specific for children. Multicenter consortia will help to facilitate adequately powered pediatric analgesic trials. [ABSTRACT FROM AUTHOR]