Search

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.

There is strong evidence that psychosocial variables, including pain catastrophizing, influence parental and child ratings of pain, pain expression, and long-term outcomes among children with chronic pain. The role of these factors among children who have communication deficits due to cerebral palsy (CP) and other intellectual and developmental disabilities is currently unclear. In this study, parental pain catastrophizing was assessed before intrathecal baclofen (ITB) pump implantation for spasticity management in 40 children and adolescents with CP, aged 4 to 24 years. Pain was assessed before and after surgery with two methods: a parent-reported pain interference scale, and behavioral pain signs during a standardized range of motion exam. Linear mixed models with clinical/demographic factors and scores from the Pain Catastrophizing Scale for Parents (PCS-P), and child spoken language ability as predictors and the pain variables as the outcomes were implemented. On average, both pain outcomes improved after surgery. Only child spoken language ability predicted change in behavioral reactivity scores, with children with phrase speech showing an increase in reactivity at follow-up compared to pre-surgery levels, on average. A significant interaction between PCS-P scores and spoken language ability on change in pain interference scores over time showed that dyads with children with phrase speech whose parents reported high PCS-P scores reported the least improvement in pain interference at follow-up. Due to the preliminary nature of the study, future work is needed to investigate the parental behaviors that mediate the relationships between parental catastrophizing and pain outcomes in this population.

Biomarkers are commonly used in clinical care and research as indicators of diseases and physiological states. Preferably, a biomarker should be readily accessible, low in cost, easy to interpret, highly specific, and sensitive to health and disease. Owing to the complexity of the pain system, no unidimensional reliable biomarker for pain has been identified that meets all of these criteria to date. In children, neurologically dependent developmental changes, maturation of physiological stress reactivity systems, and life experience add additional layers of complexity to the use of biomarkers of pain. Nevertheless, readily available and reliable biomarkers reflecting function of the pain system would greatly enhance timely and appropriate understanding and treatment of pain, especially in infants and children with communication, cognitive, and motor disabilities. This chapter examines currently available pain-related biomarkers, their use, and limitations.

Objective For people who experience social inequities and structural violence, pain and related care are inexorably linked to experiences of injustice and stigma. The purpose of this study was to examine in greater depth the experiences of pain and discrimination and stigma across diverse marginalized communities in order to recommend equity-oriented healthcare approaches. Methods This community-based qualitative study reports on four focus groups that included 36 people living with pain. All participants identified with one of three groups known to experience high levels of inequities and structural violence including an Indigenous group, a LGBTQ2S group, and two newcomer and refugee groups. Results Pain was entangled with and shaped by: social locations and identities, experiences of violence, trauma and related mental health issues, experiences of discrimination, stigma and dismissal, experiences of inadequate and ineffective health care, and the impacts of these intersecting experiences. Conclusions Equity-oriented responses to chronic pain would recognize pain not only as a biomedical issue but as a social justice issue. The EQUIP Framework is an approach to integrating trauma- and violence-informed care; culturally-safe care; and harm reduction in health care that may hold promise for being tailored to people experiencing pain and social marginalization.

Background: The 2018 Global Year for Excellence in Pain Education, an initiative of the International Association for the Study of Pain, brought worldwide attention to the need for education that crosses narrow disciplinary boundaries, addresses up-to-date research methods and findings, and encourages teamwork among trainees and mentors at different levels of training and with different perspectives. Aims: This commentary describes the development of Pain in Child Health (PICH), an interdisciplinary training program for researchers in pediatric pain at the undergraduate, graduate, and postdoctoral levels of training. Methods: Based on documentation of the structure, training processes, leadership, and membership of PICH, we outline its organization and its challenges and accomplishments over the first 12 years of its growth into a well-known international program. Results and Conclusions: Pain in Child Health began as a Strategic Training Initiative of the Canadian Institutes of Health Research in 2002 and developed into an international research training consortium featuring cross-site and cross-discipline mentorship and collaboration. PICH trainees and alumni have contributed extensively to the current scientific literature on children’s pain. PICH could serve as a possible model for training and mentorship in other specialized health research domains within and outside thestudy of pain.

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.

My research and clinical career followed a trajectory of increasing appreciation for the importance of social factors as determinants of pain experience and expression. The social contexts of children's lives determine whether infants and children are exposed to pain, how socialization in family and ethnocultural contexts lead to pain as a social experience, comprised of thoughts and feelings as well as sensory input, how others shape pain experience and expression, less so for automatic/reflexive features than purposeful representations, and how other's appraisals of children's pain reflect the observer's unique background and capacities for intervening in the child's interests. A greater understanding of the social dimensions of pain, as reflected in the social communication model of pain, would support innovation of psychological and social interventions.

Pain is often poorly recognized, inadequately assessed, and unsuccessfully managed among people in mainstream society,7,40 but this is particularly the case for people who have been historically, economically, and socially marginalized,39,46 although access to pain management is considered a basic human right.10,53 People who are indigenous, recent immigrants or refugees, of colour, LGBTQ2S, less well educated, living with mental health or substance-use challenges, or have experienced violence and trauma, among others, are vulnerable to a higher prevalence of painful medical conditions, relative to nonmarginalized people, as well as to experiencing barriers to pain management services.80,86 This study addresses the challenges of providing access to pain management for people who have been socially and economically marginalized and emphasizes the need for care at the intersection of 2 bodies of knowledge: the broad biopsychosocial model of health, given that social determinants of pain are of conspicuous importance in these populations,8,21,22,54,87 and the growing understanding of the intersections between trauma, violence, substance use, and pain.67 Those who face stigmatization and marginalization are at risk for not receiving health and social benefits broadly available to the population at large.5,6,34,38,64,85

Accurately determining pain levels in children is difficult, even for trained professionals and parents. Facial activity provides sensitive and specific information about pain, and computer vision algorithms have been developed to automatically detect Facial Action Units (AUs) defined by the Facial Action Coding System (FACS). Our prior work utilized information from computer vision, i.e., automatically detected facial AUs, to develop classifiers to distinguish between pain and no-pain conditions. However, application of pain/no-pain classifiers based on automated AU codings across different environmental domains results in diminished performance. In contrast, classifiers based on manually coded AUs demonstrate reduced environmentally-based variability in performance. In this paper, we train a machine learning model to recognize pain using AUs coded by a computer vision system embedded in a software package called iMotions. We also study the relationship between iMotions (automatically) and human (manually) coded AUs. We find that AUs coded automatically are different from those coded by a human trained in the FACS system, and that the human coder is less sensitive to environmental changes. To improve classification performance in the current work, we applied transfer learning by training another machine learning model to map automated AU codings to a subspace of manual AU codings to enable more robust pain recognition performance when only automatically coded AUs are available for the test data. With this transfer learning method, we improved the Area Under the ROC Curve (AUC) on independent data from new participants in our target domain from 0.67 to 0.72.

The current study examined youths' and their parents' perceptions concerning participation in an investigation of spontaneous and induced pain during recovery from laparoscopic appendectomy. Youth (age range 5-17 years) and their parents independently completed surveys about their study participation. On a 0 (very negative) -to-10 (very positive) scale, both parents 9.4(1.3) [mean(SD)] and youth 7.9(2.4) rated their experience as positive. Among youth, experience ratings did not differ by pain severity and survey responses did not differ by age. Most youth (83%) reported they would tell another youth to participate. Ethical issues regarding instigation of pain in youth for research purposes are examined.

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.

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.

Lifespan stage must be considered among the innumerable biological, cognitive, emotional, behavioral, and social determinants of individual variations in pain. Pain experience and expression are dynamic products of interactions among biological inheritance and daily living within diverse physical and social environments that vary substantially over the course of a lifetime. This chapter presents an overview of basic concepts needed to understand developmental changes in both intrapersonal and interpersonal features of pain in complex human environments. While one’s physiology, genetics, maturational stage, nutritional history, disease and injury exposure, and other features of biological well-being are important determinants of pain experience and expression, at all stages of life the social environment has powerful impacts on whether there is exposure to pain, how pain is experienced and expressed, how others react and deliver care to the person and, frequently, whether pain is controlled. Consideration is given to the relevance of these concepts for developmentally appropriate care and to addressing their relevance for pain assessment and management.

Understanding the impact of the social environment on human pain is essential to development of pain prevention and intervention strategies. Social factors determine whether there is exposure to pain, how it is experienced and expressed, and whether adequate treatment is provided. Inadequate prevention, assessment, and treatment are common, leading to high levels of needless pain. The importance of social factors as determinants of pain appears particularly the case for humans. The evolved human brain permitted adaptations to complex social environments and considerable sensitivity to social contexts with an impact on how pain is experienced. Cognitive and social processes assume more important roles in experiencing and responding to pain with humans than is the case with less complex species. The social communications model of pain integrates an understanding of social determinants of pain with psychological and biological systems. The biological systems evolved to support healthy behavioral adaptations to the challenges of living in complex environments.

OBJECTIVES Capacities for self-regulation that influence infant adaptation to noxious stimulation require investigation of changes in behavior over time. Prenatal exposure to maternal depression and anxiety (MDA) has been linked to altered infant pain reactivity; however, findings are inconclusive about MDA dynamic impacts on recovery. This study quantified the temporal profile of behavioral response and recovery to routine heel lance (HL) of infants with and without prenatal-MDA exposure. Aims were to examine whether MDA were associated with alterations in time-based measures of infant behavior and sequential patterning in pain expression. MATERIALS AND METHODS Videotaped facial, body, and cry behaviors of 21 full-term newborns were coded second-by-second for the duration of HL (baseline, HL, Post-HL) using validated behavioral coding systems. Mean heart rate and proportion of time infants spent exhibiting behavioral measures were compared between infant groups and over subphases of HL. Simple regressions, latency, and Yule-Q measures of effect size examined which behaviors were predicted by prenatal-MDA and magnitude of sequential association between first and subsequent behavior. RESULTS During HL, all infants reacted immediately and substantially on heart rate, facial, body, and cry measures. Facial reactivity was followed within 2 seconds by body and cry behavior. There were no group differences in magnitude of initial behavioral reactions, but during Post-HL, MDA-exposed infants spent more time crying in a weak/exhausted manner and displayed strained and erratic limb movement and immobility. CONCLUSIONS Temporal measures can further help in understanding of infant complex behavioral responses to pain. Delayed recovery in MDA-exposed infants suggested diminished capacities for self-regulation of noxious distress.

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.

Background: Evidence indicates that medical and demographic contextual factors (cFs) impact pain responses in preterm neonates, but the existing evidence is very heterogeneous. Aim: To explore the effect of cFs on pain responses to heel-stick procedures of preterm infants. Methods: This study was a secondary analysis of data collected during a randomized controlled trial examining pain response to nonpharmacological interventions across repeated heel sticks. Five heel sticks across the first 14 days of life were videotaped. Pain response was rated with the Bernese Pain Scale for Neonates (BPSN) by four raters blinded to the heel-stick phases (baseline, heel stick, recovery). Demographic and medical cFs were extracted from medical charts. Mixed single and multiple regression analyses were performed controlling for the intervention group, site and heel-stick phase. Results: Apgar scores at 1 min were negatively associated with behavioural (p = 0.002) BPSN scores, while Apgar scores at 5 min after birth were positively associated with behavioural (p = 0.006) scores. Accumulated number of painful procedures (p = 0.002) and gender (p = 0.02) were positively associated with physiological scores while continuous positive airway pressure CPAP (p = 0.009) and mechanical ventilation (p = 0.005) were negatively associated. Conclusion: Higher exposure to painful procedures, male infants and having CPAP or mechanical ventilation were cFs associated with physiological response. The only variables significantly associated with behavioural BPSN scores were Apgar scores but these relationships were inconsistent.

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.

We present a detailed framework for understanding the numerous and complicated interactions among psychological and social determinants of pain through examination of the process of pain communication. The focus is on an improved understanding of immediate dyadic transactions during painful events in the context of broader social phenomena. Fine-grain consideration of social transactions during pain leads to an appreciation of sociobehavioral events affecting both suffering persons as well as caregivers. Our examination considers knowledge from a variety of perspectives, including clinical health psychology, social and developmental processes, evolutionary psychology, communication studies, and behavioral neuroscience.

AIM: In this paper the communication model of pain is reviewed and the information then applied to understanding the acute pain experience of children in dentistry, with attention directed to improving the process of pain assessment. BACKGROUND: Expression of pain in children is of great importance as it enables them to engage others who may provide care. The experience of pain, however, is inherently private and not directly accessible to others. Therefore, it requires judgment and skill on the part of observers if pain is to be assessed accurately. In addition, there are striking individual differences in how people react to pain, which makes the assessment of pain in others an even greater challenge. Craig and colleagues [2008] have proposed the use of the social communication model of pain that gives priority to understanding the numerous social factors that affect whether children are successful in communicating painful distress. CONCLUSION: When children’s pain is underestimated or a child’s self-report is not seen as credible, there is a considerable risk of failure to deliver needed dental care.

Everybody is an expert on pain, by virtue of biological preparedness and personal experience. Unfortunately, this expertise fails large numbers of people, and we must improve our understanding through theoretical and research advances. A vast research-based literature on the nature and management of pain is now available, and there have been dramatic advances in our understanding and management of pain. Nevertheless, there continue to be major problems in the management of severe acute pain and chronic pain. It is argued that a formulation of pain that explicitly focuses upon social factors would more readily address human needs than models that focus upon biophysical and/or psychological factors alone (intrapersonal processes). Although ancient protective biological systems provide for escape and avoidance of pain, evolution of human capacities for cognitive processing and social adaptation necessitate a model of pain incorporating these capabilities (interpersonal processes). The more inclusive and comprehensive social communication model of pain is described and illustrated.

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.

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.

Children's efforts to hide or exaggerate facial expressions of pain were compared to their genuine expressions using the cold pressor task. Fifty healthy 8- to 12-year-olds (25 boys, 25 girls) submerged their hands in cold and warm water and were instructed about what to show on their faces. Cold 10 degrees C water was used for the genuine and suppressed conditions and warm 30 degrees C water was used for the faked condition. Facial activity was videotaped and coded using the Facial Action Coding System to provide objective, detailed accounts of facial expressions in each condition, as well as during a baseline condition. Parents were subsequently asked to correctly identify each of the four conditions by viewing each video clip twice. Faked expressions of pain in children were found to show more frequent and more intense facial actions compared to their genuine pain expression, indicating that children had some understanding but were not fully successful in faking expressions of pain. Children's suppressed expressions, however, showed no differences from baseline facial actions, indicating that they were able to successfully suppress their expressions of pain. Parents correctly identified the four conditions significantly more frequently than would be expected by chance. They were generally quite successful at detecting faked pain, but experienced difficulty differentiating among the other conditions. The results indicate that children are capable of controlling their facial expressions of pain when instructed to do so, but are better able to hide their pain than to fake it.

Objective To examine whether caregiver judgments of infant pain would vary systematically with different infant caregiver groups and infant age. Methods A total of 123 caregivers (41 parents, 41 in patient nurses, 41 pediatricians) viewed videotapes of the vigorous behavioral responses of healthy infants (aged 2, 4, 6, 12, and 18 months) to a routine immunization injection and provided ratings of both the affective distress and pain intensity observed. Results A principal components analysis of affective and intensity ratings yielded a weighted pain summary score for each injection event. Older infants were attributed significantly more pain than younger infants, even though the vigor of the behavioral reactions was experimentally controlled across age groups. A profile analysis contrasting observer groups indicated that pediatricians attributed significantly lower levels of pain than parents, while nurses were intermediate to the other groups, not significantly differing from either group. These systematic differences in judgments were consistent across infant age groups. Conclusions The findings reveal systematic sources of significant variations in observer judgments of infant pain. Despite an absence of differences in the behavioral reactions of the children, both the type of caregiver and their knowledge of the child’s age systematically influenced attributions of pain to infants. This work suggests the important role of caregiver role variation and perceived developmental maturity as determinants of infant pain judgments and highlights potential areas of difficulty in controlling the unnecessary suffering of infants.

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 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 nonverbal expression than to patient self-report when judging the location and severity of pain. However, patients can be successful at dissimulating facial expressions of pain, as posed expressions resemble genuine expressions in the frequency and intensity of pain-related facial actions. The present research examined individual differences in the ability to discriminate genuine and deceptive facial pain displays and whether different models of training in cues to deception would improve detection skills. Judges (60 male, 60 female) were randomly assigned to 1 of 4 experimental groups: 1) control; 2) corrective feedback; 3) deception training; and 4) deception training plus feedback. Judges were shown 4 videotaped facial expressions for each chronic pain patient: neutral expressions, genuine pain instigated by physiotherapy range of motion assessment, masked pain, and faked pain. For each condition, the participants rated pain intensity and unpleasantness, decided which category each of the 4 video clips represented, and described cues they used to arrive at decisions. There were significant individual differences in accuracy, with females more accurate than males, but accuracy was unrelated to past pain experience, empathy, or the number or type of facial cues used. Immediate corrective feedback led to significant improvements in participants' detection accuracy, whereas there was no support for the use of an information-based training program.