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Judgement analysis of case severity and future risk of disability regarding chronic low back pain by general practitioners in Ireland

  • Christopher P. Dwyer ,

    Roles Conceptualization, Data curation, Formal analysis, Supervision, Writing – original draft, Writing – review & editing

    cdwyer@nuigalway.ie

    Affiliations Centre for Pain Research, National University of Ireland, Galway, Ireland, School of Psychology, National University of Ireland, Galway, Ireland

  • Pádraig MacNeela,

    Roles Conceptualization, Data curation, Formal analysis, Methodology, Project administration, Supervision, Writing – original draft

    Affiliation School of Psychology, National University of Ireland, Galway, Ireland

  • Hannah Durand,

    Roles Formal analysis, Writing – original draft, Writing – review & editing

    Affiliations Centre for Pain Research, National University of Ireland, Galway, Ireland, School of Psychology, National University of Ireland, Galway, Ireland

  • Andrea Gibbons,

    Roles Data curation, Investigation, Methodology, Project administration

    Affiliation Health Psychology Research Unit, Royal Holloway, University of London, London, United Kingdom

  • Bronagh Reynolds,

    Roles Formal analysis, Writing – original draft

    Affiliation Centre for Pain Research, National University of Ireland, Galway, Ireland

  • Edel Doherty,

    Roles Formal analysis, Methodology

    Affiliation Discipline of Economics, J E Cairnes School of Business and Economics, National University of Ireland, Galway, Ireland

  • Sinéad Conneely,

    Roles Formal analysis, Methodology

    Affiliation School of Psychology, National University of Ireland, Galway, Ireland

  • Brian W. Slattery,

    Roles Writing – original draft

    Affiliations Centre for Pain Research, National University of Ireland, Galway, Ireland, School of Psychology, National University of Ireland, Galway, Ireland

  • Andrew W. Murphy,

    Roles Conceptualization, Resources, Supervision, Visualization

    Affiliation Discipline of General Practice, School of Medicine, National University of Ireland, Galway, Ireland

  • Brian E. McGuire

    Roles Conceptualization, Funding acquisition, Project administration, Resources, Supervision, Visualization

    Affiliations Centre for Pain Research, National University of Ireland, Galway, Ireland, School of Psychology, National University of Ireland, Galway, Ireland

Judgement analysis of case severity and future risk of disability regarding chronic low back pain by general practitioners in Ireland

  • Christopher P. Dwyer, 
  • Pádraig MacNeela, 
  • Hannah Durand, 
  • Andrea Gibbons, 
  • Bronagh Reynolds, 
  • Edel Doherty, 
  • Sinéad Conneely, 
  • Brian W. Slattery, 
  • Andrew W. Murphy, 
  • Brian E. McGuire
PLOS
x

Abstract

Chronic low back pain is a major healthcare burden that has wide ranging effects on the individual, their family, society and the workplace. However, appropriate management and treatment is often difficult, as a majority of cases are non-specific in terms of underlying pathology. As a result, there are extensive differences in both individual patient preferences for treatment and treatment decisions amongst general practitioners. The current study examined the clinical judgements of GPs in Ireland, regarding fictional patients’ case severity and future risk of disability, through judgement analysis. Judgement analysis (JA) is an idiographic regression modelling technique that has been utilised in extant healthcare research for the purpose of allocating weighting to judgement criteria, or cues, observed by professionals in their clinical decision-making. The primary aim of the study was to model two critical information utilisation tasks performed by GPs with regard to CLBP–in combining information cues to form a judgement about current case severity and a judgement about the same patient’s risk of future disability. It was hypothesised that the judgement weighting would differ across the two judgements and that judgements regarding future risk of disability would be less consistent among GPs than judgements about case severity. Results from the regression-based judgement analysis and subsequent follow-up statistical analysis provided support for both study hypotheses. Study findings are discussed in light of theory and research on judgement, clinical decision-making and chronic low back pain.

Introduction

Chronic low back pain (CLBP) is a major healthcare burden which impacts on the individual, the family, society and the workplace. CLBP affects some 16–20% of the population [1, 2] and people with CLBP frequently present to their GP for advice and management. However, appropriate management and treatment is often difficult, as approximately 90% of cases of lower back pain are non-specific (i.e. there is no identifiable pathophysiological cause [3]. In addition, there are extensive differences in treatments recommended by general practitioners (GPs) and in patient treatment preferences [46]. Furthermore, extant research indicates that both patient and contextual variables influence medical judgements regarding chronic pain [7, 8]. In the context of this high level of variability, clinical judgements about case management can also vary considerably [9, 10]. Consistent with this perspective, Chibnall and colleagues [7] recommend that research investigate the influence of these variables (e.g. contextual/patient cues and type of judgement required) in chronic pain cases.

Self-reported pain severity is a guiding factor in the treatment and management of CLBP [11]. Though pain severity is based on a number of factors, such as intensity, disability and persistence [12, 13], it is not synonymous with case severity. Case severity can be distinguished in the literature as encompassing a much broader picture of the patient as a whole, including not only the pain experience, but also distress, work status [14], psychosocial status [15], physical functioning [13], and sleep problems [16].

While case severity is defined as the seriousness of the current situation of a patient, future risk of disability is based on a more complex array of physical, psychological and social factors [1720]. Patients who have significant levels of pain-related disability are more difficult to treat and often require extensive intervention to improve overall functioning. Assessing the risk of future disability in the early stages of the pain experience (e.g. first three months) is important for the minimization and prevention of disability and prolonged suffering [17, 21].

The current study takes a novel approach in employing a regression-based statistical analysis strategy, judgement analysis, to assess how GPs in Ireland use available information sources to make judgements in the context of CLBP about case severity and future risk of disability. Judgement analysis (JA) is an idiographic regression modelling technique that has been utilised in extant healthcare research [2228] for the purpose of allocating weighting to judgement criteria, or cues, observed by professionals in their clinical decision-making [29, 30]. Consistent with social judgement theory [29], judgements are regarded as an integration of the available pieces of information presented, weighted for their importance to the form of judgement required. By presenting a set of pre-designed individual cases, an idiographic analysis of each judge’s information weighting policy can be made. Judgement policies can be assessed among judges to assess whether particular information cues are relied on by most judges, the degree to which there is idiosyncrasy in the use of information cues between judges and whether particular forms of judgement are associated with high levels of uncertainty.

It is possible to differentiate between discrete judgements within the GP’s remit for CLBP management in primary care, some of which are liable to greater uncertainty than others. Notably, in this study, case severity and the future risk of disability judgements are differentiated in a temporal sense. That is, because a case severity judgement directs the judge to integrate those information cues relevant to the patient’s situation now, whereas a judgement of the same patient’s future risk of disability requires consideration of how the same information cues predict the patient’s situation at a specified time point in the future. Arguably, it is more difficult to make a future-oriented, forecasting judgement as there is no explicit framework that could be used to model this prediction.

JA may also have a further role to play in helping clinicians to understand their case management decisions. Thus, the primary aim of the study was to model two critical information utilisation tasks performed by GPs with regard to CLBP–in combining information cues to form a judgement about current case severity and a judgement about the same patient’s risk of future disability. In this context, five cues were included based on both their relevance to the biopsychosocial model of pain (i.e. a model accounting for the biological/physiological, psychological and social factors that influence the experience of pain) [31] and their relevance to CLBP, according to articles, textbooks, interviews with GPs and review of patient medical records [11]. The five cues were Mobility (i.e. mobility of the back and spine, based on visual observation and clinical assessment), Self-esteem (feelings about the self, based on self-report); Sleep (interruption and disturbance to restful sleep, excluding early morning waking); Motivation (patient’s self-direction and focus on treatment goals); and Pain right now (back pain severity and discomfort reported in the consultation).

To reiterate, though the primary aim of the study was to model two critical information utilisation tasks performed by GPs with regard to CLBP–in combining information cues to form a judgement about current case severity and a judgement about the same patient’s risk of future disability, subsequent to this investigation, two hypotheses were developed based on the rationale that (a) as a judgement, assessment of case severity is distinct from future disability; and that (b) judging current case severity is less demanding than judging future risk of disability. It was hypothesised that the weighting of information cues would differ across the two judgements. It was also hypothesised that GPs’ judgements of future risk of disability would be less consistent than judgements of current case severity (i.e. possess less internal validity of policy–see Cook & Stewart [32]). Given the absence of gold standards or normative models with respect to the accurate/correct weighting of the information cues used [11], accuracy of the judgements was not assessed.

Methodology

Design

A judgement analysis design was used, in which individual judges with knowledge of an issue are presented with a number of cases or instances of a particular phenomenon to review [29, 30]. The case provides a unique set of values on the critical information cues or case factors that have been chosen by the case designers to represent the phenomenon. The judge renders a judgement of each case, which represents how the information cues for that case have been assimilated by the judge.

Judgement analysis is an idiographic strategy, in that a block-wise, multiple linear regression analysis is made of the judge’s set of responses made across the cases, using the information cues as predictor variables and the judgement as a criterion variable. This procedure results in a ‘judgement profile’ that displays the relative weight attributed to each case factor across the set of presented cases Specifically, judgement analysis (JA) focuses on the weighting of importance given by decision-makers to environmental cues, based on Brunswik’s lens model [33]. JA involves allocating relative weights (in this context, based on normalized standardized regression weights; that is, the quotient of the standardized regression weights by their sum) to selected judgement criteria, as widely used and accepted in JA research [26, 34, 35].

In the current study, judges were GPs asked to respond to a set of hypothetical cases of CLBP. Separate regression analyses were conducted for the discrete tasks requested of the GP–to rate the hypothetical patient in respect of case severity and risk of future disability. Regression coefficients arising from the regression analyses of each GP’s responses were used as indicators of the importance of each cue for the diagnostic judgements; that is, their weighting [36].

Follow-up statistical analyses were then carried out to evaluate the study hypotheses, which included the assessment of R2 values as a measure of the concept of cognitive control [29], used in JA as an index of the coherence of an individual judge’s judgement or information use policy. Lower R2 values are associated with both unsystematic random errors and systematic but non-modelled influences. Thus, higher R2 values indicate that the judge has more control over the judgement policy and that the information cues included in the model are more directly linked to judgement ratings.

Cluster analysis was also used in the follow-up analyses. Two two-step cluster analyses were conducted to assess the hypothesis that there would be less consistency in judgements of future risk of disability compared with judgements of current case severity. Cooksey [29] describes cluster analysis as a useful method for assessing patterns in relative weight by identifying groups of judges who share a similarity in judgement policy profiles. The two-step cluster analytic method was used with relative weights for each judgement task. This method generates clusters an automatic clustering function base on Schwarz’s Bayesian Criterion (BIC) and Log likelihood calculation of distances.

Participants

Participants were general practitioners (GPs). A list of 40 GPs was compiled from the Irish GP Training Scheme to reflect a representative sample (including rural and urban areas) contacted and invited to take part in the study. Participating GPs (N = 28; 20 males and 8 females) were aged between 33 and 68 (M = 46.93, SD = 8.84) were qualified between two and 34 years (M = 21.52; SD = 9.30); and reported seeing between two and 64 (M = 16.34, SD = 14.46) CLBP patients per month. Approximately 44% of GPs indicated that they have a special interest in musculoskeletal disorders, 42% indicated that they had an interest in orthopaedic medicine and 40% indicated a special interest in pain management.

Materials and measures

Each GP responded to 34 hypothetical cases of CLBP, presented via a booklet that was mailed to them. Two separate judgements were made for each case (i.e., current case severity and future risk of disability). The GPs were asked to read the instructions page and familiarise themselves with a standard, demographic patient profile for ‘James’. In order to minimise variability in judgements outside the remit of the five cues, all ‘cases’ (i.e. James) were identical with respect to background information. For example, James’ profile was developed from qualitative data from previous research [11] and reflected a CLBP case of a 45-year old married man with three children, who has experienced CLBP for the past five years, in which the cause of pain is not clear and is manifested in a pattern of ‘flare ups’ in pain and discomfort. Previous diagnostic tests had shown no indications for surgery. He has experienced an acute flare up for the past three months and although still in employment, he is worried about the pain becoming worse. He has presented to the GP with the on-going flare up and requests for a step up in the pain relief medication (see Table 1).

Following this standard description, 34 variations on James’ current state were presented (i.e. 34 different cases to review). Each case was presented on a separate page in a bar chart format that depicted five information cues on a 1–100 scale, namely mobility, self- esteem, sleeping patterns, motivation, and pain right now. For each of the factors, higher scores indicated a more severe problem state.

To reiterate, cues were included based on both their relevance to the biopsychosocial model of pain and their relevance to CLBP, according to articles, textbooks, interviews with GPs and review of patient medical records [11]. Although there is some variation regarding how many cues and cases can be used [37, 38], it has been suggested that the number of cases should be at least five times the number of cues; and that up to 60 cases and up to six cues is the most that should be used in any single study [39]. The current study utilised five cues within 34 cases. Definitions of the case cues were provided on a separate page that the GP was requested to keep alongside each case when working through the booklet. With respect to the psychosocial cues, broad variables were used (i.e. self-esteem and motivation), so as to not confuse GPs with potential for psychiatric illness as in the potential case of more specific cues (e.g. depression and anxiety).

Procedure

The study was performed in agreement with the Declaration of Helsinki and was approved by the Galway University Hospital Research Ethics Committee and the National University of Ireland Galway Research Ethics Committee (12/05/05). To reiterate, a list of 40 GPs was compiled from the Irish GP Training Scheme to reflect a representative sample (including rural and urban areas) contacted and invited to take part in the study. GPs interested in taking part were sent out the assessment booklet by post for self-completion within a three-week period. All GPs provided written informed consent to participate in the study. Reminder letters were sent to those who did not return the booklet after three weeks. Each GP who took part (N = 28) was given an honorarium payment of €100.

After reading the instructions and familiarising themselves with the James’ background, GPs were asked to rate James’ case severity and future risk of disability at the bottom of each page in the booklet. Each judgement was based on a 1–6 likert scale, from ‘low level problem’ to ‘high level problem’ for case severity and future risk of disability. Notably, the five cues were presented on a 1–100 scale to provide GPs with specific information about each case; however, they were asked to make their judgements on a labelled (‘low level problem’ to ‘high level problem’) 1–6 likert scale in order to facilitate judgement-making without undue cognitive load [40] or decision fatigue [41]. The two separate judgement assessments were recorded for each case. By knowing the specific weighting of each of the five cues in each case, the researchers could determine, over multiple cases, which cues GPs appeared to rely on in order to make each of their clinical judgements.

Results

Separate block-wise, multiple linear regression models were estimated for each GP for the two dependent variables (i.e. current case severity and future risk of disability). The R2 statistics indicated generally good model fit. The median R2 statistic of the current case severity regression models was 0.802 (25th, 75th percentile = 0.751, 0.830). The median R2 for the models of risk of future disability judgements was 0.736 (25th, 75th percentile = 0.660, 0.806).

Table 2 presents a descriptive overview of the two judgements with respect to the proportion of GPs who weighted each cue highest. Half of the participants gave pain right now the greatest weight when judging current case severity and 35% of GPs weighted mobility highest. There was more diversity in weightings of cues for the risk of future disability judgement. Besides motivation, which received the highest weighting by nearly 40% of the participants, a similar proportion of 14–18% weighting was distributed among the remaining four cues.

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Table 2. Descriptive overview of judgements as to the proportion of GPs who weighted each cue highest.

https://doi.org/10.1371/journal.pone.0194387.t002

This pattern is reflected in the profile of individual GP information cue weighting presented in Table 3, which contains the relative weight for each cue for each participant and the R2 for each regression model. Upon inspection of the data, it was noted that the relative weights for most of the cues were not normally distributed. A significant Kolmogorov-Smirnov statistic was obtained for the distribution of relative weight for two of the case severity cues (i.e. self-esteem and sleep) and four of the risk of future disability information cues (i.e. all bar motivation). As a result, the non-parametric sign test was used to assess for differences in the relative weights. With respect to case severity, the relative weighting of mobility (i.e. the highest weighted cue) was significantly higher than that of motivation (z = 4.347, p < .001). Pain right now was weighted significantly higher than self-esteem (z = 3.213, p = .001), sleep (z = 3.969, p < .001) and motivation (z = 4.347, p < .001). There were no other differences.

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Table 3. Relative weight for each cue for each participant and the R2 for each regression model.

https://doi.org/10.1371/journal.pone.0194387.t003

Hypothesis 1: Weighting of information cues will differ across the two judgements

With respect to differences in relative weighting of each cue across dependent variables, an analysis using the sign test revealed that relative weight of mobility was significantly higher in judgements of case severity than for risk of future disability (z = 2.694, p = .007). Similarly, pain right now was weighted significantly higher in judgements of case severity than in future risk of disability (z = 3.591, p < .001). The opposite pattern occurred in ratings of motivation (z = 3.334, p = .001) which was weighted significantly higher in judgements of future risk of disability than in case severity. There were no significant differences in ratings of sleep across the two judgement tasks.

Hypothesis 2: GPs’ judgements of future risk of disability will be less consistent than judgements of current case severity

The coherence of the GPs’ regression models was assessed by mean R2 across the two judgement tasks and by conducting a two-step cluster analysis of the judges. A paired samples t-test revealed that the R2 for case severity (M = .78, SD = .08) was significantly higher than for the equivalent regression models referring to future risk of disability (M = .71, SD = .15; t = 2.80, df = 27, p = .009).

A two-step cluster analysis of the relative weights generated in response to the case severity judgement task yielded one cluster. The BIC value for a one cluster solution was 127.84, considerably smaller than the BIC value for a two-cluster solution (139.01). This suggests that there was no meaningful further discrimination of GPs into different judgement policy types when considering the use of the five information cues.

By comparison, two clusters of judges were identified on the basis of relative weights on the future risk of disability judgement task, with a BIC value of 127.27. The cluster quality was appraised as ‘good’, with a silhouette measure of cohesion and separation of 0.5. The appearance of two clusters of participants with respect to this judgement task and only one cluster in response to the case severity judgement task is indicative of there being less consistency in the GPs’ judgement policies for the future risk of disability judgement task. Nine GPs were in cluster 1, which had a cluster profile emphasising relative weights for mobility and pain right now. Among the GPs in this cluster, the mean levels of the centroids for these two information cues were 41.22 (SD = 15.86) and 36.55 (SD = 22.92), respectively. The mean value for the centroids for the other three cues was much lower, ranging from 5.88 to 9.88. Nineteen GPs were categorised to cluster 2, which was based on motivation (mean centroid value = 39.26, SD = 24.93), self-esteem (mean centroid value = 28.36, SD = 18.82) and sleep (mean centroid value = 17.89, SD = 22.00), with lower values on mobility (mean centroid value = 6.37, SD = 6.08) and pain right now (mean centroid value = 7.89, SD = 7.73).

Discussion

The current study modelled the judgements made of two important judgement tasks relevant to the management of CLBP in general practice, namely current case severity and future risk of disability. The regression-based judgement analysis and subsequent follow-up statistical analysis provided support for both study hypotheses. Across the two judgements, there were significant differences in the relative weight attributable to four of the five information cues included in the judgement analysis. Support for hypothesis 1 showed that the GPs who took part in the study placed more emphasis on biomedical indicators when judging case severity, as reflected in higher relative weight associated with the pain right now and mobility information cues. They placed more weight on motivation and self-esteem when judging risk of future disability, suggesting a tendency toward endorsing a psychosocial model of disability. The second study hypothesis was supported as well, demonstrating that GPs’ judgements of future risk of disability were less consistent than their judgements of current case severity. The judgement analysis regression models of the future risk of disability judgements captured significantly less variance than the equivalent models of current case severity. This illustrates that GPs’ were less able to base a judgement of future disability on the five information cues of self-esteem, motivation, sleep, pain right now, and mobility than they were when judging current case severity. In addition, whereas only one cluster of judges could be identified through a cluster analysis of relative weights linked to case severity judgements, two clusters were identified among GPs when analysing relative weights for future risk of disability judgements. Notably, one group of GPs were characterised by reliance on the biomedical cues of pain right now and mobility to judge future disability risk. The other group, who comprised a majority of the sample, were characterised by their weighting of motivation and self-esteem when judging disability risk.

Though the current study revealed a number of interesting findings, it can be considered limited with respect to a relatively small sample size and should thus, be interpreted with caution. However, due to the idiographic and nomothetic nature of the statistical analyses, the large number of cases and multiple judgements required per case, the sample can reasonably be considered adequate; and moreover, the two types of judgements required by GPs in each of the presented cases was a novel strength within the current research. Another factor that should be considered is that though the cues in the current study were included based on both their relevance to the biopsychosocial model of pain and their relevance to CLBP, according to articles, textbooks, interviews with GPs and review of patient medical records [11], it must be noted that their inclusion should not imply that other important cues could not be considered. For example, other psychological factors important for the prognosis of CLBP could have been used. This is important to consider given that results suggest that biomedical cues held more weight in judging case severity; however, this weighting might have potentially been altered had different psychological and/or social factors been used. Thus, assessment of only the biopsychosocial factors used in this study could perhaps have implications for judgements in ‘real-life’ cases, when not provided on a fixed scale, but observed in an interaction with the patient. Ideally, a number of additional cues could have been added, but nevertheless, consistent with best practice of judgment analysis, the number of cases should be at least five times the number of cues; and that up to 60 cases and up to six cues is the most that should be used in any single study [39]. For purposes of minimising the effect of decision fatigue, the current study utilised 34 cases, hence five cues. The findings of the current study add to our understanding of how GPs interpret cases of CLBP by drawing attention to the context set by the judgement task. Significant differences in weightings of the same cues across judgement tasks suggest that GPs did discriminate between judgements. In using the same information differently, they were attempting to tailor the information to the demands of particular judgement tasks. Furthermore, the lesser degree of consistency applied to regression models of future risk of disability and the two different clusters of GPs identified in the analysis suggest that the future-oriented forecasting of disability was the more difficult and challenging of the two judgement tasks. With that said, lower levels of variance captured by a model could suggest unsystematic error or the presence of a different, systematic influence [29]. For example, GPs may have naïve theories of disability formation or be aware of other factors that may be predictive of disability [42, 43]. Nevertheless, the implication of these findings is clear—GPs require greater formal support in making judgements of CLBP patients, particularly, in the case judging future risk of disability. Moreover, the findings are relevant to ongoing issues raised in research literature regarding implementation of a biopsychosocial perspective in assessing and supporting patients with CLBP [4, 17, 31].

In conclusion, the current research revealed that GPs placed more emphasis on biomedical indicators when judging case severity and more weight on motivation and self-esteem when judging risk of future disability; and that GPs’ judgements of future risk of disability were less consistent than their judgements of current case severity, as evidenced by the judgment analysis regression models. These findings imply it is becoming increasingly important to identify the judgement ‘style’ of physicians’ judgement-making (e.g. case severity and/or future risk of disability), since this may well influence their approach to management of clinical cases. Knowing what information should be attended to and which pieces of information can be excluded are essential to judgements regarding CLBP and its treatment. Through the current research, judgement analysis has been identified as one such methodology. Building upon the findings of the current research, future investigation of GPs’ clinical judgement-making regarding CLBP patients should utilise judgement analysis as a potential means of assessing the accuracy of clinical judgements, not only the judgement cues used. Judgement analysis is a potentially useful way of providing structured feedback on clinical decisions as well as for teaching judgement-making in clinical settings and thus; it is recommended that future research further investigate the potential benefits of this methodology to facilitate GPs in their judgement of CLBP patients’ cases of severity and future risk of disability.

Supporting information

References

  1. 1. Hoy D, Bain C, Williams G, March L, Brooks P, Blyth F, et al. A systematic review of the global prevalence of low back pain. Arthritis Rheum. 2012;64(6):2028–37. pmid:22231424
  2. 2. Raftery MN, Sarma K, Murphy AW, De la Harpe D, Normand C, McGuire BE. Chronic pain in the Republic of Ireland—community prevalence, psychosocial profile and predictors of pain-related disability: Results from the Prevalence, Impact and Cost of Chronic Pain (PRIME) study, part 1. Pain. 2011;152(5):1096–103. pmid:21450402
  3. 3. Pillastrini P, Bonfiglioli R, Banchelli F, Capra F, Resende FL, Villafane JH, et al. The effect of a multimodal group programme in hospital workers with persistent low back pain: A prospective observational study. Med Lav. 2012;104(5):380–92.
  4. 4. Airaksinen O, Brox JI, Cedraschi C, Hildebrandt J, Klaber-Moffett J, Kovacs F, et al. Chapter 4 European guidelines for the management of chronic nonspecific low back pain. Eur Spine J. 2006;15:s192–s300. pmid:16550448
  5. 5. Coole C, Watson PJ, Drummond A. Staying at work with back pain: patients’ experiences of work-related help received from GPs and other clinicians. A qualitative study. BMC Musculoskelet Disord. 2010;11(1):190.
  6. 6. Koes B, Van Tulder M, Thomas S. Diagnosis and treatment of low back pain. BMJ. 2006;332(7555):1430. pmid:16777886
  7. 7. Chibnall JT, Tait RC, Ross LR. The effects of medical evidence and pain intensity on medical student judgments of chronic pain patients. J Behav Med. 1997;20(3):257–71. pmid:9212380
  8. 8. Tait RC, Chibnall JT. Physician judgments of chronic pain patients. Soc Sci Med. 1997;45(8):1199–205. pmid:9381233
  9. 9. Chou R, Huffman LH. Nonpharmacologic therapies for acute and chronic low back pain: A review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Ann Intern Med. 2007;147(7):492–504. pmid:17909210
  10. 10. Deyo RA. Drug therapy for back pain: which drugs help which patients? Spine. 1996;21(24):2840–9. pmid:9112708
  11. 11. MacNeela P, Gibbons A, McGuire B, Murphy A. "We need to get you focused": General Practitioners’ representations of chronic low back pain patients. Qual Health Res. 2010.
  12. 12. Parsons S, McBeth J, Macfarlane G, Hannaford P, Symmons D. Self-reported pain severity is associated with a history of coronary heart disease. Eur J Pain. 2015;19(2):167–75. pmid:24890750
  13. 13. Von Korff M, Ormel J, Keefe FJ, Dworkin SF. Grading the severity of chronic pain. Pain. 1992;50(2):133–49. pmid:1408309
  14. 14. Linton SJ. Occupational psychological factors increase the risk for back pain: a systematic review. J Occup Rehabil. 2001;11(1):53–66. pmid:11706777
  15. 15. Pincus T, Burton AK, Vogel S, Field AP. A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain. Spine. 2002;27(5):E109–E20. pmid:11880847
  16. 16. Menefee LA, Frank ED, Doghramji K, Picarello K, Park JJ, Jalali S, et al. Self-reported sleep quality and quality of life for individuals with chronic pain conditions. Clin J Pain. 2000;16(4):290–7. pmid:11153783
  17. 17. Nicholas MK, Linton SJ, Watson PJ, Main CJ. Early identification and management of psychological risk factors (“yellow flags”) in patients with low back pain: a reappraisal. Phys Ther. 2011.
  18. 18. Kent PM, Keating JL. The epidemiology of low back pain in primary care. Chiropr Osteopat. 2005;13(1):13.
  19. 19. Schultz I, Crook J, Berkowitz J, Milner R, Meloche G, Lewis M. A prospective study of the effectiveness of early intervention with high-risk back-injured workers—A pilot study. J Occup Rehabil. 2008;18(2):140–51. pmid:18404361
  20. 20. Shaw WS, Linton SJ, Pransky G. Reducing sickness absence from work due to low back pain: how well do intervention strategies match modifiable risk factors? J Occup Rehabil. 2006;16(4):591–605. pmid:17086499
  21. 21. Rasmussen-Barr E, Campello M, Arvidsson I, Nilsson-Wikmar L, Äng B-O. Factors predicting clinical outcome 12 and 36 months after an exercise intervention for recurrent low-back pain. Disabil Rehabil. 2012;34(2):136–44. pmid:21957887
  22. 22. Adderley UJ, Thompson C. Community nurses’ judgement for the management of venous leg ulceration: A judgement analysis. Int J Nurs Stud. 2015;52(1):345–54. pmid:25277880
  23. 23. Denig P, Wahlström R, Saintonge D, Chaput M, Haaijer-Ruskamp F. The value of clinical judgement analysis for improving the quality of doctors’ prescribing decisions. Med Educ. 2002;36(8):770–80. pmid:12191061
  24. 24. Harries C, Evans J. St. T., Dennis I, Dean J. A clinical judgement analysis of prescribing decisions in general practice. Trav Hum. 1996:87–109.
  25. 25. Hummers-Pradier E, Denig P, Oke T, Lagerløv P, Wahlström R, Haaijer-Ruskamp FM. GPs’ treatment of uncomplicated urinary tract infections—a clinical judgement analysis in four European countries. Fam Pract. 1999;16(6):605–7. pmid:10625136
  26. 26. Janknegt R, Steenhoek A. The system of objectified judgement analysis (Soja). Drugs. 1997;53(4):550–62.
  27. 27. Skånér Y, Strender L-E, Bring J. How do GPs use clinical information in their judgements of heart failure?: A Clinical Judgement Analysis study. Scand J Prim Health Care. 1998;16(2):95–100. pmid:9689687
  28. 28. Thompson C, Bucknall T, Estabrookes CA, Hutchinson A, Fraser K, De Vos R, et al. Nurses’ critical event risk assessments: A judgement analysis. J Clin Nurs. 2009;18(4):601–12. pmid:18042211
  29. 29. Cooksey RW. The methodology of social judgement theory. Think Reason. 1996;2(2–3):141–74.
  30. 30. Wigton RS. Social judgement theory and medical judgement. Think Reason. 1996;2(2–3):175–90.
  31. 31. Kendall NA, Burton AK, Main CJ, Watson P. Tackling musculoskeletal problems: a guide for clinic and workplace-identifying obstacles using the psychosocial flags framework: The Stationery Office; 2009.
  32. 32. Cook RL, Stewart TR. A comparison of seven methods for obtaining subjective descriptions of judgmental policy. Organ Behav Hum Perform. 1975;13(1):31–45.
  33. 33. Brunswik E. The conceptual framework of psychology: University of Chicago Press; 1952.
  34. 34. Denig P, Wahlström R, Saintonge D, Chaput M, Haaijer-Ruskamp F. The value of clinical judgement analysis for improving the quality of doctors’ prescribing decisions. Med Educ. 2002;36(8):770–80. pmid:12191061
  35. 35. Tversky A, Sattath S, Slovic P. Contingent weighting in judgment and choice. Psychol Rev. 1988;95(3):371.
  36. 36. Bring J. How to standardize regression coefficients. Am Stat. 1994;48(3):209–13.
  37. 37. Smith L, Gilhooly K, Walker A. Factors influencing prescribing decisions in the treatment of depression: A social judgement theory approach. Appl Cogn Psychol. 2003;17(1):51–63.
  38. 38. Skånér Y, Bring J, Ullman B, Strender L-E. Heart failure diagnosis in primary health care: Clinical characteristics of problematic patients. A clinical judgement analysis study. BMC Fam Pract. 2003;4(12).
  39. 39. Cooksey RW. Judgment analysis: Theory, methods, and applications: Academic Press; 1996.
  40. 40. Sweller J. Cognitive load theory: Recent theoretical advances. In: Plass JL, Moreno R, Brünken R, editors. Cognitive Load Theory. New York, NY: Cambridge University Press 2010. p. 29–47.
  41. 41. Baumeister R. The psychology of irrationality: Why people make foolish, self-defeating choices. The Psychology of Economics Decisions. 2003;1:3–16.
  42. 42. Kuijer W, Brouwer S, Preuper HRS, Groothoff JW, Geertzen JHB, Dijkstra PU. Work status and chronic low back pain: Exploring the International Classification of Functioning, Disability and Health. Disabil Rehabil. 2006;28(6):379–88. pmid:16492634
  43. 43. Hayden JA, Chou R, Hogg-Johnson S, Bombardier C. Systematic reviews of low back pain prognosis had variable methods and results—guidance for future prognosis reviews. J Clin Epidemiol. 2009;62(8):781–96. e1. pmid:19136234