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Patients Are Socially Excluded When Their Pain Has No Medical Explanation

      Highlights

      • Observers were less willing to interact with patients with unexplained pain.
      • Observers less often selected patients with unexplained pain to play a game with.
      • Observers attributed less pain to patients with unexplained pain.

      Abstract

      This study investigated whether observers socially exclude patients who experience pain that is not medically explained by means of an experimental design. Fifty-nine participants (individuals from the general population) viewed videos of 4 patients, each accompanied by a vignette describing the presence or absence of a medical explanation for their pain. Participants estimated patient's pain, and rated the sympathy felt for and the inclination to help the patient. To measure social exclusion, participants indicated their willingness to interact with the patients in several situations (Social Distance Scale). Furthermore, the participants were invited to select 2 of the 4 patients as confederates to play a game against another duo. When no medical explanation for the pain was provided, participants attributed less pain, reported feeling less sympathy, and were less inclined to help the patients with daily activities. Of particular importance to this study, participants were less willing to interact with patients with medically unexplained pain and selected less often patients with ‘medically unexplained’ pain than patients with ‘medically explained’ pain as confederates in the social game. These results are indicative of social exclusion of patients with pain for which there is no clear medical explanation.

      Perspective

      Observers socially exclude patients with pain for which there is no clear medical explanation. These findings have important clinical implications. In particular, social exclusion might have detrimental effects on the mental and physical well-being of patients with pain.

      Key words

      Chronic pain is a major health problem.
      • Crombie I.K.
      • Croft P.R.
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      Epidemiology of Pain.
      • Goldberg D.S.
      • McGee S.J.
      Pain as a global public health priority.
      Pain, and especially chronic pain, involves a significant burden on an individual level (eg, relational problems and depressive symptoms
      • Reid K.J.
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      Epidemiology of chronic non-cancer pain in Europe: Narrative review of prevalence, pain treatments and pain impact.
      ) and societal level (eg, healthcare costs
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      • Caro J.
      • Haldeman S.
      A systematic review of low back pain cost of illness studies in the United States and internationally.
      ). Even more, patients frequently report dissatisfaction with the provided care
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      Empirical research on empathy in medicine—A critical review.
      • Watkins E.A.
      • Wollan P.C.
      • Melton L.J.
      • Yawn B.P.
      A population in pain: Report from the Olmsted County health study.
      and abundant research indicates that individuals with chronic pain might be prone to stigmatization by others.
      • De Ruddere L.
      • Craig K.D.
      Understanding stigma and chronic pain: A state of the art review.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      • Holloway I.
      • Sofaer-Bennett B.
      • Walker J.
      The stigmatisation of people with chronic back pain.
      • Kool M.B.
      • van Middendorp H.
      • Boeije H.R.
      • Geenen R.
      Understanding the lack of understanding: Invalidation from the perspective of the patient with fibromyalgia.
      Stigmatizing responses have been defined as ‘devaluing and discrediting responses of observers toward individuals who possess a particular characteristic that deviates from societal norms.’
      • Crocker J.
      • Major B.
      • Steele C.
      Social Stigma.
      In the context of chronic pain, many individuals suffer from pain that is not clearly medically understood.
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      • Rief W.
      • Brähler E.
      Somatization in the population: From mild bodily misperceptions to disabling symptoms.
      • Lahmann C.
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      • Dinkel A.
      Somatoform disorders and functional somatic syndromes [in German].
      Such absence of medical evidence can be considered as a deviation from the biomedical model, which is still widely endorsed in Western societies.
      • Eccleston C.
      • Crombez G.
      Worry and chronic pain: A misdirected problem solving model.
      Accordingly, the absence of medical evidence has been related to lower pain estimates by observers,
      • Chibnall J.T.
      • Tait R.C.
      Observer perceptions of low back pain - effects of pain report and other contextual factors.
      • Chibnall J.T.
      • Tait R.C.
      • Ross L.R.
      The effects of medical evidence and pain intensity on medical student judgments of chronic pain patients.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      • Tait R.C.
      • Chibnall J.T.
      Observer perceptions of chronic low back pain.
      • Tait R.C.
      • Chibnall J.T.
      Physician judgments of chronic pain patients.
      higher beliefs of deception,
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      and less sympathy and inclination to help.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      As yet, there is no evidence that observers also socially exclude patients with medically unexplained pain. Social exclusion is one of the core features of stigmatizing behavior, is related to lower psychological well-being,
      • Major B.
      • Eccleston C.
      Stigma and social exclusion.
      and has been identified in many health conditions, such as mental health illnesses,
      • Corrigan P.W.
      • Kerr A.
      • Knudsen L.
      The stigma of mental illness: Explanatory models and methods for change.
      chronic infectious diseases,
      • Chambers L.A.
      • Rueda S.
      • Baker D.N.
      • Wilson M.G.
      • Deutsch R.
      • Raeifar E.
      • Rourke S.B.
      Stigma, HIV and health: A qualitative synthesis.
      and eating and weight disorders.
      • Puhl R.
      • Suh Y.
      Stigma and eating and weight disorders.
      Using a vignette paradigm with videos of low back pain patients performing back-straining activities, the present study had 3 aims. The primary aim was to investigate the effects of presence versus absence of medical evidence on the degree to which observers socially exclude patients. Social exclusion was measured in 2 ways. Using the Social Distance Scale (SDS),
      • Link B.G.
      • Cullen F.T.
      • Frank J.
      • Wozniak J.F.
      The social rejection of former mental patients: Understanding why labels matter.
      observers rated their willingness to interact with patients in several interpersonal situations. We expected more social distance toward patients with medically unexplained pain than toward patients with medically explained pain. We also measured social exclusion in a fictitious game. More specifically, we expected that observers would select patients with ‘medically unexplained’ pain less often than patients with ‘medically explained pain’ as confederates in the game. A second aim was to investigate the effects of absence versus presence of medical evidence upon observer pain estimates, felt sympathy for, and inclination to help the patients. By doing so, we tested the replicability and robustness of previous findings of De Ruddere and colleagues.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      We hypothesized that observers would attribute less pain, report feeling less sympathy, and being less inclined to help patients when there is no medical evidence for the pain compared with when there is medical evidence for the pain. A third aim relates to the moderating role of patient's pain behavior in the effect of presence versus absence of medical evidence upon observer responses (pain, sympathy, and inclination to help). Because a patient's pain behavior has an effect on others' reactions toward pain (social communication model of pain
      • Craig K.D.
      Social communication model of pain.
      • Goubert L.
      • Vervoort T.
      • Cano A.
      • Crombez G.
      Catastrophizing about their children’s pain is related to higher parent-child congruency in pain ratings: An experimental investigation.
      • Williams A.C.
      Facial expression of pain: An evolutionary account.
      ) we performed an exploratory investigation of its moderating role in the effect of presence/absence of medical evidence on social exclusion and estimates of pain, sympathy, and inclination to help.

      Methods

      Participants

      We aimed to have at least 40 participants in our study. This sample size is on the basis of our previous work
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      using a similar study design. In total, 60 participants from the community in Ghent contacted us in response to advertisements in a local newspaper. Exclusion criteria were being younger than 18 years (n = 0), not able to speaking fluently in Dutch (n = 0), and not having basic computer skills (ie, knowing how to manage the computer mouse; n = 1). The final sample of 59 Dutch-speaking participants (mean age [Mage] = 42 years; SD for age [SDage] = 15.68; range, 18–74 years) included 23 men (Mage = 39 years; SDage = 15.10; range, 18–65 years) and 36 women (Mage = 44 years; SDage = 16.00; range, 19–74 years). Approximately one-third of the participants were single (37%) and half of the participants were employed (48%). Half of the participants (46%) reported having had no pain in the past 6 months, 32% reported having had nonpersistent pain in the past 6 months (ie, pain for no longer than 89 days), and 22% reported having had persistent pain (ie, pain for 89 days or longer in the past 6 months). The male participants did not differ from the female participants in age (t57 = 1.13; P = .265), marital status (χ23 = .18; P = .981), employment (χ29 = 8.78, P = .457), pain in the past 6 months (χ21 = .62; P = .429), or pain persistency (χ21 = .16; P = .687). This study was approved by the ethical committee of the Faculty of Psychology and Educational Sciences of Ghent University.

      Design

      Pictures of 4 different patients with chronic low back pain were shown to the participants and were presented with vignettes. These vignettes described the presence versus absence of a medical explanation for the pain. Immediately after showing the picture and the vignette, a video was shown in which the patient performed a pain-inducing activity. Subsequently, participants were asked to estimate the patient's pain, their sympathy felt for the patient, and their inclination to help the patient with daily activities. Next, participants were presented a picture of each patient and rated their willingness to interact with the patient in different interpersonal situations. Finally, participants were asked to select 2 patients as confederates in a subsequent (fictitious) social game.

      Stimuli

      Videos and Pictures

      During the experiment, pictures and videos of 4 actual patients (not actors) from the Ghent Pain Videos of Daily Activities were presented to participants (De Ruddere and colleagues
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      ). All patients reported chronic low back pain and were in outpatient treatment for their pain at the Ghent University Hospital. All patients started the movement in an upright position with their face directed to the camera. The pain behaviors (active full body pain behavior and facial expression) of the patients have been coded before this study (see De Ruddere and colleagues
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      for the description of the coding procedure).
      For the present experimental design, videos of 2 male patients and 2 female patients were selected (all 4 patients were Caucasian; Mage = 57.3; range, 55–59 years). Two patients had a low level of pain expression and 2 patients showed high levels of pain. Scores on facial pain expression could range from 0 to 2; the score of active pain behavior was the number of seconds during which the patient displayed active pain behavior of the full body (ie, active head, torso, or limb pain behavior such as guarding, holding, or rubbing). In the present study, each participant observed all 4 patients (ie, 1 male and 1 female patient showing a low level of pain and 1 male and 1 female patient showing a high level of pain). Each patient was presented twice to participants, performing 2 back-straining movements: (1) sitting down on a chair and standing up, and (2) lying down on a bed and standing up again. The length of the video sequences was dependent on the duration of the movement, and varied between 9 and 33 seconds (see Table 1 for an overview of the duration of the videos and the scores on facial pain expression and active pain behavior of the patients averaged across the videos). Videos were displayed using Inquisit Millisecond software (Inquisit 3.0.6; Millisecond Software, Seattle, Washington) on a Dell laptop with a 17-inch color monitor.
      Table 1Scores on Facial Pain Expression and Active Pain Behavior Per Patient Averaged Across the 2 Video Sequences, and Mean Duration of the Video Sequences
      PatientFacial Pain ExpressionActive Pain BehaviorDuration, s
      FL115.516.5
      FH22021
      ML.51216
      MH1.52124
      Abbreviations: F, female; L, low pain expression displayed by the patient; H, high pain expression displayed by the patient; M, male.

      Vignettes

      The presence (arthritis or a compressed nerve in the back) versus absence of medical evidence for the pain was manipulated in the vignettes (see also De Ruddere and colleagues
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      ). Each vignette also contained information on the patient's name, age, profession, and number of children to make the pictures and video sequences of the patients more vivid/realistic for the participants. This background information was counterbalanced across the vignettes to ensure that our results could not be confounded by this background information (see Table 2 for examples of vignettes). Further, the information about the presence versus absence of medical evidence for the pain was counterbalanced across the level of pain expressed by the patient and across patient gender.
      Table 2Examples of Vignettes Used in the Experiment
      “Kris is 59 years old and a parent of 4 children. Kris works as an independent surveyor. Kris reports that he/she has been suffering from back pain for a while. On the basis of the medical examination, there appeared to be no injury in the back” (biomedical evidence absent)
      “Jo is 58 years old and a parent of 2 children. Jo works as a teacher in primary school. Jo reports that he/she has been suffering from back pain for a while. On the basis of the medical examination, there appeared to be a blocked nerve” (biomedical evidence present)
      “Kim is 57 years old and a parent of 1 child. Kim works as a counsel for the state. Kim reports that he/she has been suffering from back pain for a while. On the basis of the medical examination, there appeared to be arthritis” (biomedical evidence present)
      “Dominik is 55 years old and a parent of 3 children. Dominik works as a bank employee. Dominik reports that he/she has been suffering from back pain for a while. On the basis of the medical examination, there appeared to be no injury in the back” (biomedical evidence absent)

      Measures

      Rating Scales

      Participants used a visual analogue scale (0–100 mm) to estimate the patient's pain, their sympathy felt for the patient, and their inclination to help the patient with daily activities. Zero indicated “no pain at all,” “no sympathy at all,” and “totally unwilling,” respectively; 100 indicated “pain as bad as could be,” “a lot of sympathy,” and “totally willing,” respectively. All rating scales were presented on the computer screen.
      The SDS contains 7 items to measure observers’ willingness to interact with another person in different social situations.
      • Link B.G.
      • Cullen F.T.
      • Frank J.
      • Wozniak J.F.
      The social rejection of former mental patients: Understanding why labels matter.
      • Link B.G.
      • Yang L.H.
      • Phelan J.C.
      • Collins P.Y.
      Measuring mental illness stigma.
      In the current experiment 1 item was omitted from the original scale because it did not adequately fit the vignettes. The item, “How would you feel if one of your children would marry this person?” was considered not highly relevant because the age of the patients described in our vignettes varied between 55 and 59 years. Participants were asked to answer the questions on a visual analogue scale ranging from 0 (“not at all”) to 100 (“absolutely”). The interitem reliability (Cronbach α) of the SDS in our study was .92 (see Table 3 for the SDS items).
      Table 3SDS
      From: Link et al.
      • Link B.G.
      • Cullen F.T.
      • Frank J.
      • Wozniak J.F.
      The social rejection of former mental patients: Understanding why labels matter.
      • Link B.G.
      • Yang L.H.
      • Phelan J.C.
      • Collins P.Y.
      Measuring mental illness stigma.
      1. “How would you feel about renting a room in your home to someone like this person?”
      2. “How would you feel about having this person as a colleague?”
      3. “How would you feel having someone like this person as a neighbor?”
      4. “How would you feel having someone like this person as the caretaker of your children for a couple of hours?”
      5. “How would you feel about introducing this person to a young man/woman you are friendly with?”
      6. “How would you feel about recommending someone like this person for a job working for a friend of yours?”

      Procedure

      In the experiment room, the participant was seated in front of a computer at a distance of approximately 60 cm from the screen. Participants were told that the study examined people's ‘impression formation’ of individuals with pain. They provided a written informed consent. The experiment consisted of 3 parts. In the first part, a picture of 1 of the 4 patients was presented together with a vignette describing the absence or presence of medical evidence for the pain of the patient. Next, a video with the patient performing a pain-inducing activity was presented, and participants rated the pain, the sympathy felt for the patient, and the inclination to help the patient. This sequence was repeated with the other 3 patients; each patient was presented twice (each patient performed 2 different movements) and the videos were presented in a random order. In the second part of the experiment, a picture of each patient was shown and participants were requested to complete the SDS. Finally, in the third part, the participants were asked to take part in a subsequent social game experiment. The experimenter told the participants that the 4 patients presented in the videos were present in the university building and asked the participants to select 2 of the 4 patients as confederates in the social game. After the selection, the participants were debriefed about the purpose of the study.

      Statistical Analyses

      A 2 (medical evidence: present vs absent) × 2 (pain expression: high vs low) repeated measures multivariate analysis of variance was used to test the effect of presence versus absence of medical evidence on estimated pain, sympathy felt for the patient, and inclination to help the patient with daily activities. Furthermore, the Medical evidence × Pain expression interaction effect was tested. Next, a 2 (medical evidence: present vs absent) × 2 (pain expression: high vs low) repeated measures analysis of variance was used to test the effect of presence versus absence of medical evidence on social distance ratings (mean score on the 6 SDS ratings). In these analyses, the Medical evidence × Pain expression interaction was also tested. To be able to use the norms of Cohen d (.20 = small effect, .50 = medium effect, and .80 = large effect), effect sizes were measured using the formula of Dunlap and colleagues.
      • Borenstein M.
      • Hedges L.V.
      • Higgings J.P.
      • Rothstein H.R.
      Introduction to Meta-Analysis.
      • Dunlap W.P.
      • Cortina J.M.
      • Vaslow J.B.
      • Burke M.J.
      Meta-analysis of experiments with matched groups or repeated measures designs.
      Data of 59 participants were included in the analyses. Further, a nonparametric χ2 test measured the effect of the presence versus absence of medical evidence on the number of patients with medically unexplained pain who were ‘excluded’ (ie, not selected). In particular, because the selection of patients with ‘medically unexplained pain’ was dependent on the selection of patients with ‘medically explained pain,’ a classical t-test was inappropriate. Using the χ2 test, we tested whether each of the 6 selection possibilities occurred with equal frequency. In particular, the probability that participants selected 2 patients with ‘medically explained pain’ was 1 of 6 (15%); the probability that participants selected 2 patients with ‘medically unexplained pain’ was 1 of 6 (15%), and the probability that participants selected 1 patient with medical evidence and 1 patient without medical evidence was 4 of 6 (67%). Data of 1 participant were missing in this part of the experiment because the participant did not want to participate in the (fictitious) social game. Therefore, data of 58 participants were included in the analyses regarding the selection of patients to play the game.

      Results

      Effect of Medical Evidence and Pain Expression on Estimated Pain, Sympathy, and Inclination to Help

      Results showed a significant multivariate main effect for medical evidence (F3,56 = 5.22; P = .003) and pain expression (F3,56 = 94.6; P < .001) on the outcome variables (pain, sympathy, and help). Participants estimated lower level of pain (F1,58 = 15.31; P < .001), reported less sympathy (F1,58 = 7.49; P = .008), and less inclination to help (F1,58 = 12.68; P = .001) when medical evidence for the pain was absent compared with when medical evidence was present. Means and standard deviations of the ratings, as well as effect sizes are provided in Table 4. Furthermore, participants reported higher pain ratings (F1,58 = 287.34, P < .001; d = 3.13, 95% confidence interval [CI], 2.60–3.67), more sympathy (F1,58 = 40.07, P < .001; d = 1.17, 95% CI, .78–1.56), and a higher inclination to help (F1,58 = 105.67, P < .001; d = 1.90, 95% CI, 1.46–2.33) when pain expression was high versus low. There was no Medical evidence × Pain expression interaction (F3,56 = 2.04; P = .12).
      Table 4Differences for Pain Ratings, Sympathy, and Inclination to Help
      Medical EvidenceNo Medical EvidenceCohen d95% CI
      Pain48.547 (17.826)39.420 (17.335).72.35–1.09
      Sympathy55.534 (19.785)50.898 (17.424).51.15–.88
      Help44.394 (21.486)35.729 (21.375).66.29–1.03
      NOTE. Data are presented as mean (SD) except where otherwise noted. CI indicates CI of Cohen d. Pain indicates pain estimates; sympathy indicates sympathy for the patient; help indicates inclination to help the patient with daily activities.

      Effect of Medical Evidence and Pain Expression on Social Distance

      The analyses revealed a main effect of medical evidence (F1,58 = 6.75, P = .012; d = .48, 95% CI, .11–.84), indicating that participants were less willing to interact with the patient in interpersonal situations when medical evidence was absent (mean = 54.97; SD = 19.34) compared with when medical evidence was present (mean = 59.36; SD = 18.92). Further, there was no significant effect of pain expression on social distance (F1,58 = 3.26; P = .076), or a Medical evidence × Pain expression interaction (F1,58 = 1.13; P = .29).

      Effect of Medical Evidence and Pain Expression on Social Exclusion Behavior

      Results indicated that the 6 possibilities did not occur with equal frequencies (χ25 = 12.14; P = .033). In particular, participants selected less often 2 patients with medically unexplained pain (observed n = 6; expected n = 9.7) than 2 patients with medically explained pain (observed n = 19; expected n = 9.7). This means that participants selected less patients with medically unexplained pain as confederates than patients with medically explained pain. See Table 5 for the 6 possible patient combinations that the participants could select and the observed and expected number of participants who selected each of the combinations. There was no effect of pain expression on social exclusion behavior.
      Table 5The 6 Possible Patient Combinations That the Participants Could Select and the Observed and Expected Number of Participants Who Selected Each of the Combinations
      Patients Selected by the ParticipantObserved nExpected n
      LowM+ and HighM+199.7
      LowM+ and HighM−99.7
      LowM+ and LowM−69.7
      HighM+ and LowM−109.7
      HighM+ and HighM−89.7
      HighM− and LowM−69.7
      NOTE. In the patient column, Low indicates low pain expression, High, high pain expression; M+, medical evidence for the pain, and M−, no medical evidence for the pain. The observed n refers to the number of selections of each patient combination; the expected n refers to the number of expected selections of each patient combination under the null hypothesis ‘medical evidence is not related to the number of selections of each patient combination’ (ie, the number of participants (N = 58) divided by the number of patient combinations (N = 6).
      In general, participants' gender did not moderate the effect of medical evidence and pain expression on the ratings of pain, sympathy, and inclination to help (Gender × Medical evidence: F3,55 = .198, P = .897; Gender × Pain expression: F3,55 = .1.55, P = .213) or social distance ratings (Gender × Medical evidence: F1,57 = .132, P = .718; Gender × Pain expression: F1,57 = 2.60, P = .112). Furthermore, participants’ gender did not influence the selection of the patients (χ25 = 6.18, P = .289).

      Discussion

      The primary aim of this study was to investigate the effects of presence versus absence of medical evidence for pain on social exclusion by observers. The results indicated that observers were less willing to interact with patients whose pain is not medically explained. Furthermore, observers selected less often patients with unexplained than with explained pain as confederates in a social game of a fictitious additional experiment.
      Research on the effects of medical evidence on social exclusion behavior is scarce. Nevertheless, there is abundant research suggesting that individuals with ‘medically unexplained pain’ are more prone to stigmatization. In line with the results of our study, individuals from the general population as well as health care professionals attribute lower levels of pain to patients with unexplained pain,
      • Chibnall J.T.
      • Tait R.C.
      Observer perceptions of low back pain - effects of pain report and other contextual factors.
      • Chibnall J.T.
      • Tait R.C.
      • Ross L.R.
      The effects of medical evidence and pain intensity on medical student judgments of chronic pain patients.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      • Tait R.C.
      • Chibnall J.T.
      Observer perceptions of chronic low back pain.
      • Tait R.C.
      • Chibnall J.T.
      Physician judgments of chronic pain patients.
      feel less sympathy for these patients, and are less inclined to help them.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      Patients also report to experience stigmatizing responses. In the study of Kool and colleagues,
      • Kool M.B.
      • van Middendorp H.
      • Lumley M.A.
      • Schenk Y.
      • Jacobs J.W.
      • Bijlsma J.W.
      • Geenen R.
      Lack of understanding in fibromyalgia and rheumatoid arthritis: The Illness Invalidation Inventory (3*I).
      individuals with fibromyalgia (ie, an illness that is characterized by widespread pain that is not medically understood) experienced more discounting responses by others than individuals with rheumatoid arthritis (ie, an illness that is characterized by widespread pain that is well understood medically). Also, considerable qualitative research highlights the ubiquity of stigma in the life of individuals with chronic nonmalignant pain.
      • Dewar A.
      • White M.
      • Posade S.T.
      • Dillon W.
      Using nominal group technique to assess chronic pain, patients’ perceived challenges and needs in a community health region.
      • Glenton C.
      Chronic back pain sufferers - striving for the sick role.
      • Holloway I.
      • Sofaer-Bennett B.
      • Walker J.
      The stigmatisation of people with chronic back pain.
      • Newton B.J.
      • Southall J.L.
      • Raphael J.H.
      • Ashford R.L.
      • LeMarchand K.
      A narrative review of the impact of disbelief in chronic pain.
      • Toye F.
      • Barker K.
      “Could I be imagining this?” - The dialectic struggles of people with persistent unexplained back pain.
      • Toye F.
      • Barker K.
      Persistent non-specific low back pain and patients’ experience of general practice: A qualitative study.
      • Werner A.
      • Malterud K.
      It is hard work behaving as a credible patient: Encounters between women with chronic pain and their doctors.
      Several explanations may apply for our findings. First, the presence of medical evidence may have served to validate the pain symptoms of the patients. In line with this reasoning are the findings of De Ruddere and colleagues
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      indicating that observers ascribe more pain to patients with medically explained pain than to patients with medically unexplained pain. Furthermore, Kool and colleagues reported that patients indeed report more validating responses (ie, more understanding and less discounting) when their pain is medically understood.
      • Kool M.B.
      • van Middendorp H.
      • Boeije H.R.
      • Geenen R.
      Understanding the lack of understanding: Invalidation from the perspective of the patient with fibromyalgia.
      Observers might even have considered the absence of a medical explanation for the pain as a cue toward social cheating. Specifically, the absence of a clear medical explanation for the pain does not fit within a biomedical perspective that is still often taken for granted within Western society. Accordingly, it may lead to suspiciousness about the genuineness of the pain complaints.
      • Craig K.D.
      • Badali M.A.
      Introduction to the special series on pain deception and malingering.
      • Craig K.D.
      • Hill M.L.
      • McMurtry B.
      Detecting deception and malingering.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      In general, individuals are particularly sensitive to cues toward social cheating
      • Cosmides L.
      The logic of social exchange: Has natural selection shaped how humans reason? Studies with the Wason selection task.
      because this sensitivity may protect them from being exploited by significant others who might take benefits without earning it.
      • Kappesser J.
      • de C Williams A.C.
      Pain judgements of patients’ relatives: Examining the use of social contract theory as theoretical framework.
      It is reasonable to assume that the greater the observer's suspiciousness about the realness of the pain symptoms, the more cautious he or she will be in interacting with the persons in pain. This line of reasoning is congruent with the biocultural framework on stigmatization formulated by Neuberg and colleagues.
      • Neuberg S.
      • Smith D.
      • Asher T.
      Why people stigmatize: Toward a biocultural framework.
      According to this framework, individuals stigmatize when they perceive that their ability to derive benefits from living in a social group is threatened. One core aspect is the norm of reciprocity (ie, that the efforts of the givers are repaid by the efforts of the recipients). For example, it might be that observers were less willing to have the individual with ‘medically unexplained’ pain as a neighbor because they would not expect to get help from them when needed. A second potential explanation relates to the concept of uncertainty. In particular, we may assume that the observers in our study were rather unfamiliar with ‘medically unexplained’ pain and therefore might have felt uncertain regarding appropriate behaviors toward the patients. For example, the observers in our study might have been afraid that participation in the social game would increase the patients' pain. Increased uncertainty and a lack of familiarity with ‘stigmatized’ individuals may indeed come at the cost of appropriate social interactions.
      • Blascovich J.
      • Mendes W.
      • Hunter S.
      • Lickel B.
      Stigma, threat, and social interactions.
      Although less common, a third potential explanation might be that the observers in our study were afraid to catch some contagious disease from the patients whose pain was not medically understood. Although we know that these fears are characteristic of people's stigmatizing behaviors toward others with infectious diseases,
      • Chambers L.A.
      • Rueda S.
      • Baker D.N.
      • Wilson M.G.
      • Deutsch R.
      • Raeifar E.
      • Rourke S.B.
      Stigma, HIV and health: A qualitative synthesis.
      little is known about their influence in the context of stigma related to unexplained pain.
      The finding that patient's pain behavior was related to higher pain estimates, more sympathy, and more inclination to help on the side of the observer is consistent with research showing that patient's pain expression influences others' reactions toward patient pain,
      • Williams A.C.
      Facial expression of pain: An evolutionary account.
      such as pain estimates,
      • De Ruddere L.
      • Goubert L.
      • Stevens M.
      • Amanda A.C.
      • Crombez G.
      Discounting pain in the absence of medical evidence is explained by negative evaluation of the patient.
      • De Ruddere L.
      • Goubert L.
      • Stevens M.A.
      • Deveugele M.
      • Craig K.D.
      • Crombez G.
      Health care professionals’ reactions to patient pain: Impact of knowledge about medical evidence and psychosocial influences.
      • De Ruddere L.
      • Goubert L.
      • Vervoort T.
      • Prkachin K.M.
      • Crombez G.
      We discount the pain of others when pain has no medical explanation.
      • Goubert L.
      • Vervoort T.
      • Cano A.
      • Crombez G.
      Catastrophizing about their children’s pain is related to higher parent-child congruency in pain ratings: An experimental investigation.
      empathic and solicitous partner responses,
      • Wilson S.J.
      • Martire L.M.
      • Keefe F.J.
      • Mogle J.A.
      • Stephens M.A.
      • Schulz R.
      Daily verbal and nonverbal expression of osteoarthritis pain and spouse responses.
      and pain attending parental responses.
      • Caes L.
      • Vervoort T.
      • Devos P.
      • Verlooy J.
      • Benoit Y.
      • Goubert L.
      Parental distress and catastrophic thoughts about child pain: Implications for parental protective behavior in the context of child leukemia-related medical procedures.
      However, we did not find any effect of the patient's pain behavior on social exclusion measures. One potential explanation is that the level of pain expression, in contrast with the information about the absence versus presence of medical evidence, did not serve as a cue for the participants toward social cheating and as such, was not considered relevant in making a decision about a social interaction with the patient. Furthermore, social exclusion measures were administered after presentation of a picture of the patient showing a neutral facial expression, which might also be a potential explanation for the lack of effect of pain expression on social exclusion outcomes.
      Our results have some implications. In particular, according to a social pain account of rejection,
      • Macdonald G.
      • Leary M.R.
      Why does social exclusion hurt? The relationship between social and physical pain.
      social exclusion is a powerful social process that typically relates to ‘social pain’—‘a distressing experience arising from the perception of actual or potential psychological distance from close others or a social group.’
      • Eisenberger N.I.
      • Lieberman M.D.
      Why rejection hurts: A common neural alarm system for physical and social pain.
      Experimental research has shown that social exclusion is related to lower level of psychological well-being, characterized by lower self-esteem, more depressive symptoms, and higher negative affect among those excluded.
      • Hartgerink C.H.
      • van Beest I.
      • Wicherts J.M.
      • Williams K.D.
      The ordinal effects of ostracism: A meta-analysis of 120 cyberball studies.
      • Major B.
      • Eccleston C.
      Stigma and social exclusion.
      Although research about the relationship between social exclusion and psychological well-being is lacking in a population of individuals with pain, we might expect that social exclusion, besides other stress factors (eg, prolonged discomfort, the loss of functional ability, and sleep disturbance
      • Stokes J.
      • Evans C.J.
      • Pompilus F.
      • Shields A.L.
      • Summers K.H.
      Development of a questionnaire to assess the impact of chronic low back pain for use in regulated clinical trials.
      ), will have an adverse effect on their well-being. Social exclusion might be considered a potential cause of the frequently observed lower level of psychological well-being (more mood and anxiety disorders
      • Birtane M.
      • Uzunca K.
      • Taştekin N.
      • Tuna H.
      The evaluation of quality of life in fibromyalgia syndrome: A comparison with rheumatoid arthritis by using SF-36 Health Survey.
      • Walker E.
      • Keegan D.
      • Gardner G.
      • Sullivan M.
      • Katon W.
      • Bernstein D.
      Psychosocial factors in fibromyalgia compared with rheumatoid arthritis .1. Psychiatric diagnoses and functional disability.
      ) of individuals with medically unexplained pain. Furthermore, social exclusion might even be related to a decrease in prosocial behavior
      • Twenge J.M.
      • Baumeister R.F.
      • DeWall C.N.
      • Ciarocco N.J.
      • Bartels J.M.
      Social exclusion decreases prosocial behavior.
      and to an increase in aggressive behavior,
      • VanBeest I.
      • Carter-Sowell A.R.
      • van Dijk E.
      • Williams K.D.
      Groups being ostracized by groups: Is the pain shared, is recovery quicker, and are groups more likely to be aggressive?.
      which may, in turn, heighten the stigmatizing responses of others. For example, professional health care providers might ‘socially exclude’ patients by distancing themselves or by making a referral. This, in turn, might lead to defensive behaviors and hostility in patient and health care providers.
      • Stone L.
      Blame, shame and hopelessness: Medically unexplained symptoms and the “heartsink” experience.
      Finally, social exclusion might also affect the physical condition of the individual with pain, for example, through restricted access to health care, housing, and sport facilities. Because of potential adverse effects of social exclusion on the overall well-being and behavior of individuals with chronic pain, it is important to address social exclusion and stigma in therapeutic pain programs. Despite the ubiquity of stigma in the lives of individuals with chronic pain,
      • Holloway I.
      • Sofaer-Bennett B.
      • Walker J.
      The stigmatisation of people with chronic back pain.
      programs aimed at teaching individuals with pain how to deal with others' stigmatizing reactions is to our knowledge scarce.
      Some limitations, each of which point to directions for future research, need attention. First, the results may not be generalized toward relatives, friends, or professional health care providers. We might expect that our effects would be less pronounced when observers have a good relationship with the individual in pain. In particular, according to the Intergroup Contact Theory,
      • Allport G.W.
      The nature of prejudice.
      positive contact between in- and outgroup members is a buffer against negative relations among them. Future research might focus on the moderating effect of a positive relationship between the observer and the individual in pain. Furthermore, all participants in our study were Caucasian, which may limit the generalizability of the results toward non-Caucasian individuals. Second, 22% of the observers in our study (n = 13) reported to have had persistent pain during the past 6 months. One might expect that the effect of the absence of medical evidence on social exclusion would be less pronounced in observers with (medically unexplained) pain themselves. We were not able to test this hypothesis because of the small number of participants reporting pain. Future research should investigate whether observers with ‘medically unexplained’ pain react in a different way to patients with ‘medically unexplained’ pain than observers with no pain or with medically explained pain. Third, observers' willingness to interact with patients in interpersonal situations was measured according to self-reports and 1 behavioral measure (ie, the exclusion of patients from participation in a social game). These results may not be generalized toward other social exclusion behaviors such as the exclusion of patients from participation in other social activities, sports, etc. Therefore, future studies that focus on different behavioral responses of observers toward individuals with pain are needed to further investigate the effect of presence versus absence of medical evidence on observers' stigmatizing responses toward individuals with pain. Fourth, except for the participants' gender, our study did not investigate observer variables that could moderate the effects of the absence versus presence of medical evidence on observer responses. Future research might benefit from a focus on potential observer and patient characteristics influencing the effect of contextual information on observers’ responses.

      Conclusions

      To conclude, our results indicate that individuals with pain that is not clearly medically understood are prone to social exclusion behavior of observers.

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