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Does experience influence judgments of pain behaviour? Evidence

Feb 14, 2017

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  • Pain Res Manage Vol 6 No 2 Summer 2001 105

    ORIGINAL ARTICLE

    Does experience influencejudgments of pain behaviour?

    Evidence from relatives of pain patients and therapists

    Kenneth M Prkachin PhD1, Patty Solomon PhD2, Teresa Hwang BA2, Susan R Mercer PhD3

    1University of Northern British Columbia, Prince George, British Columbia; 2McMaster University, Hamilton, Ontario; 3University of Otago, Dunedin, New Zealand

    Correspondence: Dr KM Prkachin, Psychology Program, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia V2N 4Z9. Telephone 250-960-6633, fax 250-960-5536, e-mail [email protected]

    Received for publication March 28, 2000. Accepted October 10, 2000

    KM Prkachin, P Solomon, T Hwang, SR Mercer. Does experience influence judgments of pain behaviour?Evidence from relatives of pain patients and therapists. Pain Res Manage 2001;6(2):105-112.

    OBJECTIVE: Judgments about an individuals pain can beprofoundly important to sufferers. Relatively few studies haveexamined variables that may affect observers judgments of thepain of others. The present article reports two studies investi-gating the relationship between different kinds of exposure topain problems and observers ratings of the pain intensity ofpatients.DESIGN: In the first study, 82 observers were classified intogroups with positive and negative family histories of chronicpain. They viewed a videotape showing the facial expressions ofshoulder pain patients undergoing physiotherapy assessmentsand rated the pain experienced by the subjects. In the secondstudy, the data from observers having no experience with painproblems were compared with data collected from therapistshaving considerable experience with pain problems.RESULTS: Observers with a positive family history of chronicpain attributed greater pain to the patients than those with a neg-ative family history of chronic pain. Professionals pain judg-ments were lower than those of control subjects.CONCLUSIONS: Together, the findings imply that ones expe-riences with the different problems of pain patients may affectpain judgments. Alternative interpretations of the findings areconsidered.

    Key Words: Bias; Experience; Facial expression; Observation;Pain, Sensitivity; Shoulder pain

    Lexprience modifie-t-elle les jugementsports sur les comportements rvlateurs dela douleur? Rponse de parents ayant connudes personnes souffrantes ainsi que dethrapeutesOBJECTIF : Les jugements sur la douleur peuvent savrer extrme-ment importants pour les personnes souffrantes. Relativement peudtudes ont examin les variables susceptibles de modifier le juge-ment dobservateurs port sur la douleur des autres. Le prsent articlefait tat de deux tudes sur le lien entre les diffrents problmes con-cernant lexposition la douleur et lvaluation de lintensit de ladouleur par des observateurs dans un groupe de patients.PLAN DTUDE : Dans la premire tude, 82 observateurs ont tclasss en deux groupes : ceux ayant une exprience familiale posi-tive de la douleur chronique et ceux ayant une exprience ngative.On leur a prsent, sur bande vido, lexpression faciale de patientsprouvant des douleurs lpaule au cours dune valuation en phy-siothrapie et on leur a demand de coter la douleur ressentie par lessujets. Dans la deuxime tude, les chercheurs ont compar les don-nes provenant dobservateurs qui navaient pas t exposs ladouleur celles provenant de physiothrapeutes qui y avaient tfortement exposs. RSULTATS : Les observateurs qui avaient des antcdents fami-liaux positifs de douleur chronique ont accord une cote plus leveque ceux qui avaient des antcdents familiaux ngatifs.Lvaluation de la douleur par les professionnels tait plus faible quecelle des tmoins.CONCLUSION : Dans lensemble, les rsultats donnent penserque lexprience personnelle de la douleur peut modifier le jugementsur la douleur. Sont galement envisages dautres interprtationspossibles des rsultats.

  • The actions that people take in the presence of a suffererare profoundly important. This is true both in the naturalenvironment and in the clinic. In the natural setting, an observ-ers perception of a sufferers pain may determine whether heor she will encourage the sufferer to seek help, rest, relax ormove on to other activities. According to Fordyce (1), suchconsequences may strengthen or weaken the sufferers futurepain behaviour. In clinical settings, a therapists judgment ofthe presence or intensity of a sufferers pain may make thedifference between aggressive or conservative treatmentsand may govern the pace of rehabilitation efforts.

    The variables that affect judgments about the pain of oth-ers are poorly understood. To investigate these problems, itis helpful to understand pain as a communication process inwhich some antecedent event (eg, tissue damage, ongoinginjury, central stimulation) induces an internal state. Thesufferers behaviour then changes in a way that provides anexternal referent (eg, linguistic and paralinguistic cues, gri-macing, self-protective or self-care behaviour) for that state.This referent may then be broadcast into the social envi-ronment where observers can detect, interpret and takeaction on it. Rosenthal (2) has outlined an A (internal state)to B (behavioural sign) to C (observers decoding) model ofthis process and has discussed the nature of the questionsthat can be addressed at each point.

    Some research on pain behaviour has focused on the A toB phase of this process: investigators have attempted to iden-tify behaviours that encode the internal state. For example, aset of facial actions that take place during pain has been iden-tified (3). These actions appear to provide a sensitive indica-tion of the intensity of pain, when evaluated against thecriterion of the sufferers judgment (4-7). Relatively fewerstudies have focused on the B to C phase of this process how people decode the evidence about pain available inbehaviour and when they have, it has been primarily to val-idate the properties of the pain signal itself. There has beenlittle inquiry into the possibility that observers may showsystematic differences in how they detect, interpret and takeaction on evidence of pain in others.

    Prkachin et al (6) provided evidence that observersjudgments of others pain may pose special problems thatwarrant attention. Untrained observers viewed videotapesof shoulder pain patients who had undergone a series ofmovements during a physiotherapy assessment. Thepatients had provided ratings (A in Rosenthals model) oftheir pain with each movement. Measurement of their facialbehaviour during the movement provided an index of theexternal referent (B) to their pain. The observers gave theirjudgments (C) of the intensity of the pain the patients felton each trial, using the same rating scale used by thepatients. The observers judgments were highly reliableand sensitive to gross variations in patients pain states.Nevertheless, several aspects of their performance wereproblematic. First, they did not appear to be especially sen-sitive to fine variations in patients facial expressions.Second, the correlations between their judgments and thepatients subjective reports were not as strong as those

    between measured facial behaviour and the patientsreports. This suggested that although the evidence thatobservers could use to make a reliable judgment aboutpatients pain was present, they did not use it effectively.Third, observers underrated the absolute magnitude of thepatients pain (relative to the criterion of the patients self-reports) systematically and appreciably.

    These findings suggest that untrained observers mayhave a less than optimal ability to use information about suf-fering that is available in the behavioural display. Furtherunderstanding of judgment processes may enhance our abil-ity to identify when this is likely to be a special problem andmay suggest means of remedying the problem. In addition,these findings draw attention to a distinction that can bemade between two aspects of performance in such situa-tions. On the one hand, observers may vary in their sensitiv-ity to variations in a sufferers pain. This is indicated bycovariations between the magnitude of the observers judg-ment and either the behavioural referent or the patientsreport. On the other hand, observers may vary in the weightthey place on a particular bit of evidence about pain. That is,observers may systematically underrate (or, conceivably,overrate) pain relative to sufferers, independent of their sen-sitivity to variations in the sufferers states.

    It is reasonable to ask what variables may affectobservers evaluations of the pain of others. One naturalexpectation is that experience should influence howobservers process information about pain behaviour andthereby affect their ratings of others pain. Two groups ofpeople that may be expected to show systematic variationsin their judgments of pain are people who have lived with achronic pain sufferer and health care professionals who dealwith pain sufferers on a routine basis. The present paperpresents two studies in which the pain ratings of such indi-viduals were contrasted with those of people having littleexperience with pain problems and with those of sufferersthemselves.

    STUDY 1Surprisingly, few studies have examined how family mem-bers interpret pain behaviour, although there has been nolack of speculation about the role of family members in thedevelopment and treatment of pain problems (8,9). Familysystems theorists (10,11) suggest that family characteristicssuch as overinvolvement and enmeshment may contributeto pain problems, but they are silent on whether painpatients family members perceive pain behaviour in anyunique way. Similarly, the behavioural approach to chronicpain (1) emphasizes that family members are sensitive to theexpression of pain and may respond to maintain or mini

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