ABSTRACT Introduction The Consortium to Research Individual, Interpersonal and Social Influences in Pain (CRIISP) is a 4‐year UK university collaboration investigating how thoughts and feelings, personal relationships and lifestyle can affect chronic pain. Patient and public involvement in research recognises that researchers' conceptions of health and illness can be enriched and sense‐checked by those of people experiencing a health condition. Published literature reports a gap in meaningful patient and public involvement in research into chronic pain, for example, during early study design. Input in this formative stage aimed to ensure the research proposed had a patient‐centred focus which may benefit study implementation. We describe how the authors sought to address this gap and established a diverse public involvement (PI) network to support the CRIISP research. Methods Thirty‐six adult public contributors were appointed to work alongside the research teams. Lessons learned are presented under the themes: optimising collaborative working, recruitment of public contributors, supporting public involvement throughout CRIISP and the retention of public contributors. Throughout this paper, we refer to the term ‘public involvement’ rather than ‘patient and public involvement’ in accordance with the NIHR definition which incorporates people with a range of experiences. Results Working in partnership with our public contributors, we have embedded PI throughout a chronic pain research programme using an innovative and collaborative process. Conclusion This model may inform others to maximise the potential of PI within their research. Patient or Public Contribution The paper reports the collaboration between public contributors with a lived experience of chronic pain and the Consortium to Research Individual, Interpersonal and Social influences in Pain (CRIISP) researchers, by means of a large public involvement network.

Sex and gender contribute to the variation in pain experience. A range of biological, psychological, and social factors are relevant, which point to potential pain mechanisms and the reasons for this sex/gender-based variation. This review provides a brief critical overview of the evidence for these patterns. It draws on both experimental and clinical studies and identifies some of the biological and psychosocial factors that are thought to impact on men and women's pain. There are limitations and gaps in understanding, and numerous challenges exist, ranging from difficulties with concepts through to methodology. There is a focus on gender as a dimensional set of psychosocial constructs, as this offers one approach to help enhance our understanding of men and women's pain.

Multiple large longitudinal cohorts provide opportunities to address questions about predictors of pain and pain trajectories, even when not anticipated in design of the historical databases. This focus article uses two empirical examples to illustrate the processes of assessing the measurement properties of data from large cohort studies to answer questions about pain. In both examples, data were screened to select candidate variables that captured the impact of chronic pain on self-care activities, productivity and social activities. We describe a series of steps to select candidate items and evaluate their psychometric characteristics in relation to the measurement of pain impact proposed. In UK Biobank, a general lack of internal consistency of variables selected prevented the identification of a satisfactory measurement model, with lessons for the measurement of chronic pain impact. In the English Longitudinal Study of Ageing, a measurement model for chronic pain impact was identified, albeit limited to capturing the impact of pain on self-care and productivity but lacking coverage related to social participation. In conjunction with its supplementary material, this focus article aims to encourage exploration of these valuable prospectively collected data; to support researchers to make explicit the relationships between items in the databases and constructs of interest in pain research; and to use empirical methods to estimate the possible biases in these variables. Perspective This focus article outlines a theory-driven approach for fitting new measurement models to data from large cohort studies, and evaluating their psychometric properties. This aims to help researchers develop an empirical understanding of the gains and limitations connected with the process of re-purposing the data stored in these datasets.

Self-initiated actions often generate sensory signals perceived to be less intense than identical signals generated externally. This phenomenon, known as sensory attenuation, is particularly robust for nonpainful tactile sensations. For pain, however, even if the stimulation is self-generated and predictable, it remains painful, albeit sometimes slightly less intense. This difference may reflect the functional divergence between pain and nonpainful sensations, with the sense of agency playing a central role in this distinction. Across 2 experiments involving 61 pain-free adults, we investigated the attenuation of self-induced pain and nonpainful sensations across different stimulation modalities, contexts, and agency levels. We found that self-induced attenuation depended on stimulation modality rather than intensity, with significant reductions for modalities involving strong motoric components and high spatiotemporal alignment (eg, mechanical pressure), in line with the internal forward model. Individuals' trait agency played a pivotal role, with stronger agency associated with enhanced attenuation of nonpainful sensations and mild pain, but reduced attenuation of intense pain. Sex differences also emerged with stronger attenuation effects in men, who also reported higher levels of agency. This study is the first to show that trait-level agency differentially modulates attenuation for painful and nonpainful sensations and the first to explore sex differences. By comparing pain with nonpainful touch, we proposed that self-induced sensations are not attenuated uniformly but shaped by evolutionary priorities such that socially or playfully mediated sensations are more readily suppressed, while high-threat sensations like pain resist qualitative suppression to preserve their protective function.

Sex and gender are important variables in research, but they are inconsistently explored. The international PAINDIFF Network makes 13 recommendations for studying sex and gender as variables in pain research, which are applicable across the spectrum of biopsychosocial research. Five universal recommendations apply to the majority of research studies: (1) include males and females as standard practice, (2) account for sex in randomization or counterbalancing and testing order, (3) power for sex differences when sex is a primary experimental variable, (4) include detailed reporting of experimental design, and (5) conduct sex-disaggregated analysis and reporting. Three additional recommendations specifically for preclinical studies and five additional recommendations for human and clinical studies are included. Recommendations for stakeholders, such as editors, reviewers, funding bodies and policymakers, have also been developed. Wide adoption and implementation of these recommendations will reduce variability, improve reproducibility and enhance the translatability of research findings within and beyond the field of pain.

ABSTRACT:Pain is not experienced in isolation; it is affected by and affects other people. Interactions between parents and partners and people living with pain affect beliefs, emotions and behaviours, and pain progress and change. We searched systematically for longitudinal studies of associations between specific familial, dyadic, interpersonal factors and quantitative pain transitions. We coded studies for risk of bias. For the narrative synthesis, we grouped findings by dyads-parents and children, and people with pain and their partners (usually spouses), and then by the psychosocial mechanism/s. We described certainty of evidence for each pain transition and each mechanism. Patient and public contributors were involved throughout. Of 52 studies, 38 were of parents and children (27,814 dyads) and 14 of partners (4904 dyads). Three groups of predictive factors were identified for parent and child studies: parent mental health, parent cognitions, and parent behaviours. Parental anxiety (but not depression) predicted children's onset of pain and worsening; the evidence was of moderate certainty and almost exclusively involved mothers. Evidence that some parental behaviours, such as protective behaviours, were associated with worse child pain was of very low certainty. The evidence for partners was of poor quality, precluding synthesis. The review highlights that most interpersonal pain research fails to capture the complex dynamics of longstanding relationships and highlights the difficulty of doing so using simple models.

Pain states fluctuate over time and across situations. Similarly, there is variation in risk and protective factors and how they impact on these pain-related transitions. We are interested in whether such variations are more than random, and whether they can be accounted for by observed variables. The availability of large longitudinal datasets, such as UK Biobank (https://www.ukbiobank.ac.uk/), offers a unique opportunity to study these variations at scale. However, such datasets bring a high risk of bias (eg, confounding) and danger of over-interpretation. It is therefore important to be transparent about our causal thinking. Directed acyclic graphs (DAGs) are graphical representations of the hypothesized causal relationships between variables. They are used to identify the smallest set of variables that need to be adjusted to remove confounding bias in estimating the causal effect of an exposure on an outcome. However, use of DAGs in pain research is not common, despite their potential to guide study design and data analysis. In this article, we present a workflow for building a DAG using domain knowledge from 3 different sources: researchers (theory-based), people with lived experience (person-based), and the literature (evidence-based). We created a DAG for the putative effect of executive function on the maintenance of chronic high-impact pain. The resulting DAG provides a valuable framework for guiding future research on the role of executive functioning in pain, and it underscores the broader potential of using DAGs to improve causal inference in pain research.

BACKGROUND:Pain is one of the most prevalent health issues in Europe, yet the quality of pain education for healthcare professionals remains unclear. This study assessed the status of undergraduate and postgraduate pain education for nurses, physicians, psychologists, and physiotherapists across Europe, identifying key strategies to enhance training and improve healthcare outcomes. METHODS:A study using multiple methods was conducted, comprising a scoping review, an online survey of educators, and qualitative interviews with EFIC chapters and professional educational bodies. RESULTS:The scoping review of 11 studies revealed a paucity of evidence, with significant heterogeneity in the hours dedicated to pain training and inconsistencies in both content, teaching, and assessment methods across European curricula. The survey of educators (n = 511) showed wide variability in pain education coverage, with psychology curricula particularly underrepresented compared to the more structured programmes in medicine and physiotherapy. The interviews highlighted curriculum constraints, lack of resources, and limited specialised staff as key barriers. They also underscored the importance of integrating pain education across all disciplines through international and interdisciplinary collaboration to enhance training efforts. CONCLUSIONS:Significant gaps persist in the depth, consistency, and delivery of pain education for undergraduate and postgraduate health professionals across Europe. The absence of standardised, evidence-based curricula underscores the need for consistent pain education across all disciplines. Implementing targeted educational standards, increasing interdisciplinary training, and supporting qualified educators are essential to address this fragmented landscape. Standardising pain education has the potential to greatly improve patient outcomes by equipping healthcare professionals with more effective pain management skills. SIGNIFICANCE STATEMENT:This multiple method study provides an updated and comprehensive overview of the current state of pain education for healthcare professionals in Europe at undergraduate and postgraduate levels. Substantial gaps remain in the depth, consistency, and delivery of pain education for both undergraduate and postgraduate healthcare professionals across Europe. This underscores the need to enhance pain education at the undergraduate level, with EFIC's existing medicine and physiotherapy resources offering potential models, alongside wider efforts to implement comprehensive postgraduate training. Standardising the delivery of targeted pain education has the potential to greatly improve patient outcomes by equipping healthcare professionals with more effective pain management skills.

Background To study pain, data on pain characteristics, possible triggers and consequences - such as the impact of pain on people’s lives - need to be available. When not collated, described and/or organised in a systematic manner, it can be difficult to assess how useful an existing dataset may be for one’s project. This data note describes and categorises the complex and multi-modal indices of pain available in the Avon Longitudinal Study of Parents and Children (ALSPAC). Methods Data from two generations of the ALSPAC cohort; index child participants (Generation 1, G1), their mothers and fathers/mothers’ partners (Generation 0, G0) were used. Search terms such as ‘pain’, ‘ache’, ‘hurt’, ‘sore’, specific pain conditions, labour pain and methods of pain relief were used to identify pain and pain-related variables. These data were extracted from all waves of data collection. We developed pain categories and subsequently categorised variables in an iterative process. Repeated measurements of the same variables over waves of data collection were also identified. Results We identified 21 categories of pain variables, which were subsequently grouped into themes: pain characteristics, extended pain characteristics and causes, treatment for pain, pain interference and pain-related to specific events. Pain and pain-related data have been collected from G1 participants, G0 mothers, and G0 partners, although there are fewer data for the partners. There were some repeated measurements, most commonly, of pain location. As is typical with longitudinal birth cohort studies, maternal proxy-reports were used during participants’ younger years and self-reports were utilised from adolescence onwards. Conclusions Researchers interested in studying pain can feasibly do so in two generations of a regional UK population who have been followed up over 30 years. ALSPAC can be used to study pain from the early years through to young adulthood and in mothers from the perinatal period onwards.

Pain states fluctuate over time, and across situations. Similarly, there is variation in risk and protective factors and how they impact on these pain-related transitions. We are interested in whether such variations are more than random, and whether they can be accounted for by observed variables. The availability of large longitudinal datasets, such as UK Biobank (https://www.ukbiobank.ac.uk/), offers a unique opportunity to study these variations at scale. However, such datasets bring a high risk of bias (e.g. confounding) and danger of over-interpretation. It is therefore important to be transparent about our causal thinking. Directed Acyclic Graphs (DAGs) are graphical representations of the hypothesized causal relationships between variables. They are used to identify the smallest set of variables that need to be adjusted for to remove confounding bias in estimating the causal effect of an exposure on an outcome. However, use of DAGs in pain research is not common, despite their potential to guide study design and data-analysis. In this paper we present a workflow for building a DAG using domain knowledge from three different sources: researchers, people with lived experience, and the literature. We created a DAG for the putative effect of executive function on the maintenance of chronic high impact pain. The resulting DAG provides a valuable framework for guiding future research on the role of executive functioning in pain and it underscores the broader potential of using DAGs to improve causal inference in pain research.

Abstract Technology offers possibilities for quantification of behaviors and physiological changes of relevance to chronic pain, using wearable sensors and devices suitable for data collection in daily life contexts. We conducted a scoping review of wearable and passive sensor technologies that sample data of psychological interest in chronic pain, including in social situations. Sixty articles met our criteria from the 2783 citations retrieved from searching. Three-quarters of recruited people were with chronic pain, mostly musculoskeletal, and the remainder with acute or episodic pain; those with chronic pain had a mean age of 43 (few studies sampled adolescents or children) and 60% were women. Thirty-seven studies were performed in laboratory or clinical settings and the remainder in daily life settings. Most used only 1 type of technology, with 76 sensor types overall. The commonest was accelerometry (mainly used in daily life contexts), followed by motion capture (mainly in laboratory settings), with a smaller number collecting autonomic activity, vocal signals, or brain activity. Subjective self-report provided “ground truth” for pain, mood, and other variables, but often at a different timescale from the automatically collected data, and many studies reported weak relationships between technological data and relevant psychological constructs, for instance, between fear of movement and muscle activity. There was relatively little discussion of practical issues: frequency of sampling, missing data for human or technological reasons, and the users' experience, particularly when users did not receive data in any form. We conclude the review with some suggestions for content and process of future studies in this field.

Sex differences are a robust finding in many areas of adult health, including cardiovascular disease, psychiatric disorders, and chronic pain. However, many sex differences are not consistently observed until after the onset of puberty. This has led to the hypothesis that hormones are primary contributors to sex differences in health outcomes, largely ignoring the relative contributions of early developmental influences, emerging psychosocial factors, gender, and the interaction between these variables. In this paper, we argue that a comprehensive understanding of sex and gender contributions to health outcomes should start as early as conception and take an iterative biopsychosocial-developmental perspective that considers intersecting social positions. We present a conceptual framework, informed by a review of the literature in basic, clinical, and social science that captures how critical developmental stages for both sex and gender can affect children’s health and longer-term outcomes. The literature on pediatric chronic pain is used as a worked example of how the framework can be applied to understanding different chronic conditions.

Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain remain rarely addressed in the context of pain prevention and management. In this review, we aim to 1) examine the broad scope of social determinants and consequences of pain and their interactions across multiple levels of organization, and 2) provide a framework synthesizing existing concepts and potential areas for future work on social aspects of pain, drawing upon socioecological, intersectional, and life course approaches. Integrating interdisciplinary theory and evidence, we outline pathways through which multilevel social factors and pain may affect each other over time. We also provide a brief summary of intrapersonal aspects of pain, which are thought to operate at the interface between individuals and the social context. Progressing from micro- to macrolevel factors, we illustrate how social determinants of pain can directly or indirectly contribute to pain experiences, expression, risk, prognosis, and impact across populations. We consider 1) at the interpersonal level, the roles of social comparison, social relatedness, social support, social exclusion, empathy, and interpersonal conflict; 2) at the group or community level, the roles of intimacy groups, task groups, social categories, and loose associations; and 3) at the societal level, the roles of political, economic, and cultural systems, as well as their policies and practices. We present examples of multilevel consequences of pain across these levels and discuss opportunities to reduce the burden and inequities of pain by expanding multilevel social approaches in pain research and practice. Perspective Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain are often unclearly defined, hindering their use in pain prevention, management, and research. We summarize the scope of social aspects of pain and provide a framework synthesizing existing concepts and potential areas for future work.

The focus of this article, within this BBI horizons special issue, is on sex, gender, and pain. We summarise what is currently known about sex- and gender-related variations in pain, exploring intersectional biological and psychosocial mechanisms, and highlight gaps in knowledge and understanding. Five key challenges with the exploration of sex and gender in pain research are presented, relating to: conceptual imprecision, research bias, limitations with binary descriptions, integrating sex and gender, and timely adoption/implementation of good research practice. Guidance on how to overcome such challenges is provided. Despite clear evidence for sex and gender differences in pain, there are conceptual and methodological barriers to overcome. Innovation in methods and approach can help develop more effective and tailored treatment approaches for men, women, boys, girls, and gender-diverse people.

1. Introduction We present a framework for the study of states of chronic pain and transitions between those states. We capture in the framework the dynamic nature of pain: people live with pain that changes over time. First, we offer definitions of both acute and chronic pain and explore the contextual considerations related to the common use of this temporal dichotomy. Second, we promote the importance of incorporating the impact pain has on a person's life. Finally, we discuss the challenges and opportunities inherent in implementing this common approach. Our goal is to produce a framework for the study of the development, maintenance, and resolution of chronic pain. Whether a single brief event or a constant feature of life, pain interrupts to prioritise protection, interferes with activity, reduces quality of life, and can alter identity.44 Protection is achieved by escape from harm, avoidance of perceived danger, withdrawal for respite and repair, and communication of incapacity and environmental risk; longer-term protection is achieved by learning the cues for pain and injury.53 From this perspective, pain is most usefully considered a need state, fundamentally a motivational drive to protect.49 This approach centres our attention on the consequences of pain for the person in their context, on its duration and its impact. 2. A person's pain status Pain is defined as “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”34 There is a logical case of a state of “no pain,” but to have no pain is a rare occurrence, only recently made possible by the advent of anaesthesia/analgesia. A state of the continuous absence of any pain at all is profoundly abnormal, appearing only as congenital nociceptor deficiency or dysfunction. It is far from adaptive, notably leading to major clinical problems associated with the absence of defensive responding and learning with a consequent severe shortening of life expectancy.9,50,51 2.1. Acute and chronic The terms “acute” and “chronic” represent a temporal dichotomy, with “acute” meaning short lived or immediate, and chronic meaning long term. Colloquially, however, both can be used interchangeably to mean “bad,” causing confusion in clinical encounters when patients use these as terms for severity or impact and clinicians use them for temporality.5 In this article, we use “acute pain” to mean pain of short duration, without any implication of severity or urgency. The pragmatic challenge in its use is the length of this short duration. Acute pain is typically defined as lasting from onset to 3 months in duration and so encompasses everything from a momentary muscular “cramp” to postoperative pain.27,52 Therefore, acute pain is both common and a normal part of everyday life. The few studies that establish the base rate of everyday pain generally report high incidence. For example, in 1 observational study of everyday pain in 3- to 7-year-olds, the event rate was 0.33 incidents per hour per child.31 Painful bumps and scrapes in the playground are normal. For adults, episodes of naturally occurring acute pain are also common. In a Europeanwide study of 8506 patients, 70% of adults reported at least 1 pain event a month (such as headache, menstrual pain, and muscle pain).48 Acute pain can also occur deliberately as part of a social process (eg, body adornment, contact sport, or ritual). However, most everyday acute pain does not require clinical intervention; it is self-limiting. Clinical studies often focus on pain related to medical procedures or that occurs as the result of illness, disease, or injury (accidental, self-induced, or medically induced), and although acute pain can be relatively straightforward to manage, in particular when the timing and extent of trauma are controlled, it is not always so simple. Acute pain can be complicated for healthcare professionals to assess and manage when there are concurrent symptoms or conditions, it occurs in the presence of chronic pain, or when communication about pain is difficult, for instance in an emergency.23 Furthermore, we recognise that the 3-month limit is an arbitrary distinction that can lead to problems. For example, it does not account for life stage. Consider the case of new-born babies who receive repeated needle sticks for diagnostic tests: Each pain may be acute, but the pain has been present for most of the child's life. For a baby, less than 3 months is not a “short” duration. These and other concerns have led some to question the focus on duration in definitions, suggesting instead a focus on presumed mechanism.8 Pain of longer duration is known as “chronic pain.” Typically, chronic means having lasted for 3 months or more, as captured in the IASP definition and more recently included in ICD-11.38 Historically, chronic pain was considered to start at 6 months for adults and 3 months for children. The problem of definitions that privilege duration has been discussed,46 and 3 months for adult and child is now thought more clinically relevant. Given the consensus on the use of a 3-month definition, this serves as the dividing boundary that differentiates chronic from acute pain. This definition has some difficulties. As with acute pain, 3 months is an absolute cutoff: 3 months for a 6-month-old is 50% of a life, whereas for a 60-year-old, 3 months is 0.4% of a life. If a child of 2 months has lived their life in pain, this definition of chronic would not apply, which in some circumstances would be more clinically meaningful.25 Furthermore, many people report pain that changes in quality or location and which fluctuates and/or is episodic. Consider that the International Headache Society classifies a number of chronic headaches as episodic with different decisions about the number, frequency, and extent of episodes,20 as do the Rome IV Diagnostic Criteria for Functional Gastrointestinal Disorders, which are less exact and use phrases such as “continuous,” “nearly continuous,” and “intermittent.”37 Including frequency in the definition of chronic low back pain may be useful and lead to a more accurate identification of treatment responders.22 In short, a category of chronic pain needs to encompass the experience of people who have intermittent, episodic, or continuous pain, pain of different quality and intensity, and the pain may be a sole primary complaint, secondary to disease and illness, or one of several chronic complaints.29,43 The variability in nosology emerging from different clinical specialities, and considerations of duration in the context of longevity, does not negate the value of a simple duration dichotomy (acute–chronic). We argue for the informed use of context when considering its use, and the need to look beyond simple labels when combining data or insights. It is a useful starting point to explore the specific features of that temporal definition in context. 2.2. High- and low-impact acute and chronic pain Pain can impact multiple aspects of a person's life. We prefer “impact” over other common terms, such as disability, suffering, or distress, because it draws attention to the diverse effects of pain on the person. It is generally used conditionally to refer to the consequences of pain on a particular outcome.13,39,42 Duration is not a good predictor of impact. A momentary pain of an accident, incident, or procedure can have drastic effects on a person. One example is the cumulative effects of repeated exposure to acute pain in new-born babies on brain development.2 Another is the potential role of discrete painful events as psychologically traumatic, leading to major impact.35 And, a third is of uncontrolled pain near end of life, which may last less than 3 months but which can be devastating for a person and significant others.28 Discriminating by impact is more common in considerations of chronic pain. In particular, “high-impact chronic pain”has been defined in the United States as activity limitation47 and later as activity and participation limitation,33,39 contrasted with a category of chronic pain without limitations. This thinking was more recently captured in the Graded Chronic Pain Scale Revised as high impact compared with mild or bothersome pain.45 These categories allow for greater discrimination when trying to bridge between population-based studies of prevalence of chronic pain and clinical studies with adults expressing healthcare needs. The prevalence of adults with high-impact chronic pain is more typically estimated conservatively as at least 5%, in contrast to the headline population figures for all chronic pain, conservatively estimated at 20%.33,55 The idea that chronic pain can have low or no impact is an interesting one. Indeed, the potential for the existence of pain without impact is at the heart of the biopsychosocial model6,16,17 and a treatment goal in psychological rehabilitation.54 Although the complete resolution of chronic pain is desirable as a treatment objective, the transition to a state of low(er) impact chronic pain is often more realistic and still an important objective for individuals, healthcare providers, and society. An example is in the context of normal ageing with accommodation to life with increasingly unreachable goals achieved by altering those goals.12 For our purposes, high impact is defined by the extent of difficulties in function and disability (self-care, occupational engagement, and social activities)26 in line with the WHO. Again, we propose an informed and context-dependent use, with the need to look beyond simple labels when combining data or insights. It is a useful starting point to explore the specific features of how high impact can be determined from the available measurement. 3. States and transition Taking duration and impact together, we propose a transitional framework for the study of 5 categorical “states” (Table 1 and Fig. 1), which include acute low-impact pain, acute high-impact pain, chronic low-impact pain, chronic high-impact pain, and a “resolved” no chronic pain state. Table 1 - States of pain. Duration Impact Features Acute pain Low impact Pain of less than 3-mo duration that is not associated with major self-care, occupational, and social activity restrictions Pain of less than 3-mo duration can occur in a normal everyday context. Examples are inoculation, minor injury, or pain incidental to aesthetics or recreation Acute pain High impact Pain of less than 3-mo duration that is associated with major social, personal, or role restrictions Pain of less than 3-mo duration can have a major impact. Examples are major trauma, headache, end of life pain Chronic pain Low impact Pain of 3 mo or more duration that is not associated with major social, personal or role restrictions Pain of 3 mo or longer can be related to a disease or be a primary disorder of the nervous system but can have minor impact Chronic pain High impact Pain of 3 mo or more duration that is associated with major social, personal, or role restrictions Pain of 3 mo or longer can be related to a disease or be a primary disorder of the nervous system but can have major impact Chronic pain (resolution) No impact The chronic pain of interest can progress to a new state of resolved chronic pain This new state is similar to acute pain of low impact in which everyday pain may occur but is always in the context of having had chronic pain Figure 1.: A framework for the establishment, maintenance, and adaptation of high- and low-impact chronic pain: Pain is described with 2 dominant dimensions: duration and impact. Both are dichotomised to establish specific states. Duration is split into acute pain defined as pain lasting less than 3 months and chronic as pain of 3-month duration or longer. Impact is split into low and high impact defined as a minor or major impact on self-care, occupational, and social activities. No specific measurement technology or method for determining the cutoffs is prescribed because this is a frame to capture multiple contexts of study. These 2 dimensions allow for 5 possible states represented in the oval shapes, including: acute low-impact pain and acute high-impact pain, chronic low-impact pain and chronic high-impact pain, and finally a special case of resolution of chronic pain. These 5 states allow for 10 possible transitions over time, which are given in Table 2. One cannot change from chronic to acute pain. This is a static representation of a set of dynamic processes, and we recognise that one can move between states over time, especially between chronic low impact and chronic high impact. We recognise also that chronic pain, once resolved, can relapse.Although we refer here to pain duration (acute, chronic) and impact (high, low) as dichotomies, we recognise the continuous, overlapping and dynamic aspect of the pain experience. For many people, pain is an additional burden to other diseases. Our choices here are illustrative not ontological providing a framework for investigation—placing an emphasis on measurement and its use within individual investigations. In line with the US pain strategy,26 we recognise that introducing categories creates opportunities for research, in particular population-based research, but can under some circumstances lead to a statistical loss of information. Table 2 outlines 10 possible trajectories of change in states, representing transitions (or absence of transition) in a person's pain state. We are interested in the onset of chronic pain, whether it is low or high impact, and its starting point of low- or high-impact acute pain. We are also interested in no change, or the maintenance of chronic pain, whether low or high impact, and the factors that lead to people becoming “stuck” in their pain state.3 And finally, we are interested in change in state, worsening from low impact to high impact, or improving from high impact to low impact, or a resolution from chronic low- or high-impact pain back: transition to a new normal state in which the specific pain(s) meeting the criteria for chronicity has/have resolved, but the natural rate of everyday pain resumes. These states and transitions are outlined in Figure 1. Table 2 - Possible transitions between chronic pain states. Chronic pain status 1st observation 2nd observation Onset Acute low impact Chronic low impact Onset Acute low impact Chronic high impact Onset Acute high impact Chronic low impact Onset Acute high impact Chronic high impact Change (worsening) Chronic low impact Chronic high impact Change (improving) Chronic high impact Chronic low impact Change (resolution) Chronic low impact Chronic pain resolution Change (resolution) Chronic high impact Chronic pain resolution Maintenance Chronic low impact Chronic low impact Maintenance Chronic high impact Chronic high impact 4. Further considerations Our focus on duration and impact raises several issues for consideration: (1) Pain can be described by its pathological cause, mechanism, intensity, location, frequency, diurnality, or as a collection of features in a measure of severity. Such features are important, but, in this framework, they would be held in analyses as potential predictors, correlates, or process variables in an examination of impact and duration rather than part of their definition. (2) The premise that a person can have chronic pain with low impact clashes with the ICD-11 definition of primary chronic pain, a clinical diagnostic scheme that assumes high impact as a core part of the definition.30 (3) The concept of transition has been questioned because of an often tacit acceptance of a change in mechanism from acute to chronic pain. We make no reference to specific mechanisms but agree with the recommendation, where possible, “…to track individual pain types over time because they are likely to have different pain progression and resolution mechanisms and require different interventions.”15 (4) We also acknowledge that at any time point, acute and chronic pain can co-occur, but in this framework are focusing on the transition to/from chronic pain. (5) Related is the assumption that chronic pain is pain that is refractory to treatment. There is a need to establish evidence for refractory chronic pain monitoring treatment(s) and their unsuccessful outcomes. To date, there is no broadly accepted and generalisable definition of treatment-resistant chronic pain. (6) Similarly, Figure 1 is a static representation of changes in pain state. We recognise that one can move between high- and low-impact pain, and that pain can resolve and then relapse.40 (7) Living with longstanding pain can have a broad lasting impact on life that might endure past pain resolution. (8) A focus on duration and impact privileges the individual. Chronic pain has an impact beyond the individual to other individuals, to society and to the economy. This duration-impact framework has been developed in the context of a major UK research programme investigating the psychosocial determinants of high-impact chronic pain7 funded by the Advanced Pain Discovery Platform.1 The APDP has a focus on determining the causal influences on the onset and maintenance of high- and low-impact chronic pain. The consortium7 is exploring determinants of pain-state transitions using existing databases such as ALSPAC,4,18,32 ELSA,14 UK BIOBANK,41 HWW,24 and HEAF21 the synthesis of findings across published studies,19 and through new investigations. This framework is the first step in helping to clarify clinical and research questions. First, we need to understand how to manage the uncertainty inherent in the use of measurement technology designed to capture impact and establish how far what has already been measured corresponds with, or diverts from, this framework. Second, as we are interested in factors that are causally relevant to the onset, maintenance, and change in states over time, testing causal models needs to be carefully formulated. And third, this framework can direct the selection of appropriate endpoints for intervention in attempting to alter unwanted pain states. As important as pain offset (resolution) is the improvement in impact status, from high to low. A reasonable treatment outcome for many, and therefore a clinical endpoint, is to move from high-impact to low-impact chronic pain.10,11,36 5. Conclusion We propose a framework for studying the biopsychosocial influences on the onset, maintenance, and change in of chronic pain state. In accepting and interrogating the common dichotomies of duration (acute, chronic) and impact (high, low), we recognise the challenges inherent in dichotomizing continuous and dynamic experience. Pragmatically, however, this allows us to propose 5 unique states of pain and 10 transitions. This framework promotes a consideration of impact over time on the person with pain and will enable investigation of the causal determinants of states and changes in state. Conflict of interest statement The authors have no conflict of interest to declare.

Increasing attentional focus away from pain can affect pain experience, suggesting that cognitive strategies that move attentional allocation may be a moderator of pain. In a pre-post-design, the present study examined the effects of 2 cognitive strategies used in pain contexts, thought suppression and focused distraction, on subsequent pain-related attention. Thought suppression was hypothesized to increase pain-related attention, whereas focused distraction was expected to reduce it. Influences of both anxiety and sex were also considered, as secondary questions. 139 (86 women, 53 men) healthy, pain-free participants were randomly assigned to use either thought suppression or focused distraction during a mild cold pressor test (CPT). Pain-related attention was examined using a dot-probe and an attentional blink task, pre-and post-CPT. Questionnaires about relevant cognitive and emotional aspects, demographics, and pain were completed. Results showed no difference in the effect of the 2 pain inhibition strategies on pain-related attention. The hypothesized rebound effect in thought suppression on pain-related attention did not emerge. However, thought suppression showed a short-term benefit in comparison to focused distraction regarding reported pain and perceived threat during the cold pressor test. Few sex differences were found. Thus, the cognitive strategies affected pain outcomes, but did not influence pain-related attention. PERSPECTIVE: Cognitive strategies could help with pain through changing attention allocation. In this study, the effects of the 2 cognitive strategies thought suppression and focused distraction on pain-related attention in men and women were examined. Elucidating mechanisms that lie behind pain strategies that focus on changing attention may help improve treatments.

aCentre for Pain Research, University of Bath, Bath, United Kingdom bDepartment of Psychology, University of Bath, Bath, United Kingdom Address: Department of Psychology, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom. Tel.: +44(0)1225 383671; fax: +44(0)1225 386752. E-mail address: [email protected] (E. Keogh). Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.

Male–female differences in pain perception and experience have been consistently observed in adult populations. Such differences are theorized to be related to differences in biological (e.g., sex hormones, endogenous pain modulation, and genetics), psychological (e.g., differences in coping), and social (e.g., gender role socialization) factors. In comparison to the adult literature, male–female differences in pediatric pain are less consistently observed, and differences in the prevalence rates of chronic pain conditions appear to emerge around the time of puberty. This chapter explores the evidence for sex and gender differences in pain within pediatric groups. We argue that it is critical to take a development biopsychosocial perspective to fully understand the similarities and differences between boys and girls in pain.

Pain is a major source of global suffering, with women bearing the greatest burden. Alongside biology, psychological and social factors, including gender, help explain these differences. However, there has been no direct attempt to develop a unified social psychological model of men and women's pain. By drawing on approaches to both gender and pain, a gender context model of pain is presented. It proposes that pain is partly influenced by the gender context in which it occurs, which operates at both individual and interpersonal levels. The model is used to structure an appraisal of the existing evidence around gender and pain, and explore whether the model helps explain why such variation occurs. It is argued that despite evidence for an association between gender and pain, there are empirical gaps that need to be addressed. Implications and directions for future investigations into sex, gender and pain are considered.