Kathryn A. Birnie

Systematic review and meta-analysis of distraction and hypnosis for needle-related pain and distress in children and adolescents.

OBJECTIVE To systematically review the evidence (and quality) for distraction and hypnosis for needle-related pain and distress in children and adolescents. To explore the effects of distraction characteristics (e.g., adult involvement, type of distracter), child age, and study risk of bias on treatment efficacy.  METHODS 26 distraction and 7 hypnosis trials were included and self-report, observer-report, and behavioral pain intensity and distress examined. Distraction studies were coded for 4 intervention characteristics, and all studies coded for child age and study risk of bias.  RESULTS Findings showed strong support for distraction and hypnosis for reducing pain and distress from needle procedures. The quality of available evidence was low, however. Characteristics of distraction interventions, child age, and study risk of bias showed some influence on treatment efficacy. CONCLUSIONS Distraction and hypnosis are efficacious in reducing needle-related pain and distress in children. The quality of trials in this area needs to be improved.

Sex differences in experimental pain among healthy children: a systematic review and meta-analysis.

Summary A meta‐analysis found that girls had increased pain intensity on the cold pressor task, and lower pain tolerance and threshold in response to heat pain. ABSTRACT Sex differences in response to experimental pain are commonly reported in systematic reviews in the adult literature. The objective of the present research was to conduct a systematic review and meta‐analysis of sex differences in healthy childrens responses to experimental pain (eg, cold pressor, heat pain, pressure pain) and, where possible, to conduct analyses separately for children and adolescents. A search was conducted of electronic databases for published papers in English of empirical research using experimental pain tasks to examine pain‐related outcomes in healthy boys and girls between 0 and 18 years of age. Eighty articles were eligible for inclusion and were coded to extract information relevant to sex differences. The systematic review indicated that, across different experimental pain tasks, the majority of studies reported no significant differences between boys and girls on pain‐related outcomes. However, the meta‐analysis of available combined data found that girls reported significantly higher cold pressor pain intensity compared to boys in studies where the mean age of participants was greater than 12 years. Additionally, a meta‐analysis of heat pain found that boys had significantly higher tolerance than girls overall, and boys had significantly higher heat pain threshold than girls in studies where the mean age of participants was 12 years or younger. These findings suggest that developmental stage may be relevant for understanding sex differences in pain.

Contemporary Use of the Cold Pressor Task in Pediatric Pain Research: A Systematic Review of Methods

UNLABELLED The cold pressor task (CPT) is an ethical experimental pain task widely used by pediatric pain researchers to examine a variety of important theoretical and clinical questions. The purpose of this systematic review was to describe contemporary use of the CPT in pediatric pain research to identify possible methodological and procedural inconsistencies and inform future research. All papers using the CPT to examine pain-related outcomes in children ≤18 years old published after 2005 were identified, 2005 being when published pediatric CPT studies were last reviewed and guidelines for pediatric use of the CPT were published. Information related to samples, CPT methodology, and pain outcomes was recorded. Thirty-six published papers, involving 2,242 children (aged 3-18 years) from both healthy and clinical samples, met review inclusion criteria. Several aspects of CPT methodology with significant potential to impact pain outcomes were found to be inconsistently implemented and reported, including water temperature, use of informed versus uninformed ceilings, and the presence of observers during the CPT. Self-report child pain intensity and pain tolerance were common outcomes. A number of refinements for use of the CPT in pediatric pain research are suggested. PERSPECTIVE The cold pressor task is a commonly used experimental method in pediatric pain research. This systematic review reveals important methodological inconsistencies in its use and suggestions for improvements to previously published guidelines.

The Cold Pressor Task: Is it an Ethically Acceptable Pain Research Method in Children?

OBJECTIVES The cold pressor task (CPT) is an experimental method of inducing pain. Ethical concerns have been raised regarding the nontherapeutic induction of pain in children. The objectives of this study were to describe the ethical challenges and acceptability of the CPT from the perspective of researchers, children and parents. METHODS Study 1:16 researchers completed a survey regarding their experiences obtaining ethical approval and use of the CPT in pediatric research. Study 2: 175 children and 194 parents answered questions about their experiences participating in studies that used the CPT. RESULTS Full ethics board review was generally required. Adverse events were rare and transient. The majority of researchers, children, and parents reported positive experiences with the CPT. CONCLUSIONS The CPT is judged by researchers, children, and parents to be an acceptable research method. The CPT can be used ethically in pediatric research with appropriate study safeguards.

When does pain matter? Acknowledging the subjectivity of clinical significance

The International Association for the Study of Pain (IASP) defines pain as ‘‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage,’’ acknowledging that ‘‘pain is always subjective’’ [20]. This definition, based on individual differences in pain perception, is the cornerstone of pain research and practice and is consistent with personalized patient-centered care [21]. Health professionals frequently make judgments about the clinical significance of pain, either to assess treatment effectiveness or inform clinical decision making. Judgments are highly individual, as patients with similar diagnoses may have diverse treatment needs. It follows that our conceptualization of clinically significant pain in research should be more personalized, as would be consistent with the IASP definition and good clinical practice. The discussion of clinical significance in pain has largely centered on the assessment of treatment effectiveness [8,12], although it has also been used to categorize pain intensity [5,9]. Used in these ways, determining the clinical significance of pain is useful for describing pain prevalence or for judging treatment success. However, it begs the question: when should pain be considered clinically significant? How we address this question has significant implications for claims made about well-managed vs undertreated pain. Conceptualizing pain as a subjective experience leads us away from previous methods of determining clinical significance that rely on group-derived comparisons and apply uniform standards to all patients [22]. If pain is subjective, it follows that the clinical significance of pain should also be determined on an individual basis. This review describes interpretations of clinical significance in pain, with particular attention to assessing change in pain after treatment and for classifying pain levels. Existing group-based methods for determining clinical significance for both applications are reviewed, followed by the presentation of alternative and more personalized approaches. We advocate for these modified methods for determining clinical significance that offer greater sophistication in their respect for an individual’s subjective experience of pain.

Offspring of Parents with Chronic Pain: A Systematic Review and Meta-Analysis of Pain, Health, Psychological, and Family Outcomes

Abstract Offspring of parents with chronic pain may be at risk for poorer outcomes than offspring of healthy parents. The objective of this research was to provide a comprehensive mixed-methods systematic synthesis of all available research on outcomes in offspring of parents with chronic pain. A systematic search was conducted for published articles in English examining pain, health, psychological, or family outcomes in offspring of parents with chronic pain. Fifty-nine eligible articles were identified (31 population-based, 25 clinical, 3 qualitative), including offspring from birth to adulthood and parents with varying chronic pain diagnoses (eg, mixed pain samples, arthritis). Meta-analysis was used to synthesize the results from population-based and clinical studies, while meta-ethnography was used to synthesize the results of qualitative studies. Increased pain complaints were found in offspring of mothers and of fathers with chronic pain and when both parents had chronic pain. Newborns of mothers with chronic pain were more likely to have adverse birth outcomes, including low birthweight, preterm delivery, caesarian section, intensive care admission, and mortality. Offspring of parents with chronic pain had greater externalizing and internalizing problems and poorer social competence and family outcomes. No significant differences were found on teacher-reported externalizing problems. The meta-ethnography identified 6 key concepts (developing independence, developing compassion, learning about health and coping, missing out, emotional health, and struggles communicating with parents). Across study designs, offspring of parents with chronic pain had poorer outcomes than other offspring, although the meta-ethnography noted some constructive impact of having a parent with chronic pain.

A practical guide and perspectives on the use of experimental pain modalities with children and adolescents

Use of experimental pain is vital for addressing research questions that would otherwise be impossible to examine in the real world. Experimental induction of pain in children is highly scrutinized given the potential for harm and lack of direct benefit to a vulnerable population. However, its use has critically advanced our understanding of the mechanisms, assessment and treatment of pain in both healthy and chronically ill children. This article introduces various experimental pain modalities, including the cold pressor task, the water load symptom provocation test, thermal pain, pressure pain and conditioned pain modulation, and discusses their application for use with children and adolescents. It addresses practical implementation and ethical issues, as well as the advantages and disadvantages offered by each task. The incredible potential for future research is discussed given the array of experimental pain modalities now available to pediatric researchers.

A comprehensive categorical and bibliometric analysis of published research articles on pediatric pain from 1975 to 2010.

Abstract The field of pediatric pain research began in the mid-1970s and has undergone significant growth and development in recent years as evidenced by the variety of books, conferences, and journals on the topic and also the number of disciplines engaged in work in this area. Using categorical and bibliometric meta-trend analysis, this study offers a synthesis of research on pediatric pain published between 1975 and 2010 in peer-reviewed journals. Abstracts from 4256 articles, retrieved from Web of Science, were coded across 4 categories: article type, article topic, type and age of participants, and pain stimulus. The affiliation of the first author and number of citations were also gathered. The results suggest a significant increase in the number of publications over the time period investigated, with 96% of the included articles published since 1990 and most research being multiauthored publications in pain-focused journals. First authors were most often from the United States and affiliated with a medical department. Most studies were original research articles; the most frequent topics were pain characterization (39.86%), pain intervention (37.49%), and pain assessment (25.00%). Clinical samples were most frequent, with participants most often characterized as children (6-12 years) or adolescents (13-18 years) experiencing chronic or acute pain. The findings provide a comprehensive overview of contributions in the field of pediatric pain research over 35 years and offers recommendations for future research in the area.

Psychological Interventions for Vaccine Injections in Children and Adolescents: Systematic Review of Randomized and Quasi-Randomized Controlled Trials.

Background:This systematic review evaluated the effectiveness of psychological interventions for reducing vaccination pain and related outcomes in children and adolescents. Design/Methods:Database searches identified relevant randomized and quasi-randomized controlled trials. Data were extracted and pooled using established methods. Pain, fear, and distress were considered critically important outcomes. Results:Twenty-two studies were included; 2 included adolescents. Findings showed no benefit of false suggestion (n=240) for pain (standardized mean difference [SMD] −0.21 [−0.47, 0.05]) or distress (SMD −0.28 [−0.59, 0.11]), or for use of repeated reassurance (n=82) for pain (SMD −0.18 [−0.92, 0.56]), fear (SMD −0.18 [−0.71, 0.36]), or distress (SMD 0.10 [−0.33, 0.54]). Verbal distraction (n=46) showed reduced distress (SMD −1.22 [−1.87, −0.58]), but not reduced pain (SMD −0.27 [−1.02, 0.47]). Similarly, video distraction (n=328) showed reduced distress (SMD −0.58 [−0.82, −0.34]), but not reduced pain (SMD −0.88 [−1.78, 0.02]) or fear (SMD 0.08 [−0.25, 0.41]). Music distraction demonstrated reduced pain when used with children (n=417) (SMD −0.45 [−0.71, −0.18]), but not with adolescents (n=118) (SMD −0.04 [−0.42, 0.34]). Breathing with a toy (n=368) showed benefit for pain (SMD −0.49 [−0.85, −0.13]), but not fear (SMD −0.60 [−1.22, 0.02]); whereas breathing without a toy (n=136) showed no benefit for pain (SMD −0.27 [−0.61, 0.07]) or fear (SMD −0.36 [−0.86, 0.15]). There was no benefit for a breathing intervention (cough) in children and adolescents (n=136) for pain (SMD −0.17 [−0.41, 0.07]). Conclusions:Psychological interventions with some evidence of benefit in children include: verbal distraction, video distraction, music distraction, and breathing with a toy.

Simple Psychological Interventions for Reducing Pain From Common Needle Procedures in Adults: Systematic Review of Randomized and Quasi-Randomized Controlled Trials.

Background:This systematic review evaluated the effectiveness of simple psychological interventions for managing pain and fear in adults undergoing vaccination or related common needle procedures (ie, venipuncture/venous cannulation). Design/Methods:Databases were searched to identify relevant randomized and quasi-randomized controlled trials. Self-reported pain and fear were prioritized as critically important outcomes. Data were combined using standardized mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI). Results:No studies involving vaccination met inclusion criteria; evidence was drawn from 8 studies of other common needle procedures (eg, venous cannulation, venipuncture) in adults. Two trials evaluating the impact of neutral signaling of the impending procedure (eg, “ready?”) as compared with signaling of impending pain (eg, “sharp scratch”) demonstrated lower pain when signaled about the procedure (n=199): SMD=−0.97 (95% CI, −1.26, −0.68), after removal of 1 trial where self-reported pain was significantly lower than the other 2 included trials. Two trials evaluated music distraction (n=156) and demonstrated no difference in pain: SMD=0.10 (95% CI, −0.48, 0.27), or fear: SMD=−0.25 (95% CI, −0.61, 0.10). Two trials evaluated visual distraction and demonstrated no difference in pain (n=177): SMD=−0.57 (95% CI, −1.82, 0.68), or fear (n=81): SMD=−0.05 (95% CI, −0.50, 0.40). Two trials evaluating breathing interventions found less pain in intervention groups (n=138): SMD=−0.82 (95% CI, −1.21, −0.43). The quality of evidence across all trials was very low. Conclusions:There are no published studies of simple psychological interventions for vaccination pain in adults. There is some evidence of a benefit from other needle procedures for breathing strategies and neutral signaling of the start of the procedure. There is no evidence for use of music or visual distraction.