[German transcultural translation of the Injustice Experience Questionnaire]

Opioid Consumption in Chronic Pain Patients: Role of Perceived Injustice and Other Psychological and Socioeconomic Factors

BACKGROUND

Chronic pain is a complex biopsychosocial phenomenon. Lifestyle, behavioral, socioeconomic, and psychosocial factors such as depression and perceived injustice are often associated with the development of chronic pain and vice versa. We sought to examine the interaction of these factors with opioid intake.

METHODS

At our institution, 164 patients with chronic pain undergoing an interdisciplinary assessment within a three-month period participated in the study and completed the Injustice Experience Questionnaire (IEQ). Data regarding opioid intake, pain levels, pain diagnosis, depression, anxiety, stress, quality of life, pain-related disability, habitual well-being, occupational status, and ongoing workers compensation litigation were extracted from the patients' charts.

RESULTS

Approximately one-fourth of the patients used opioids. The IEQ total was significantly higher in patients using Schedule III opioids. Depression, but not the anxiety and stress scores, were significantly higher in patients using opioids. There were no significant differences regarding pain-related disability, habitual well-being, and the coded psychosocial diagnoses. In the patient group without opioids, the percentage of employed persons was significantly higher but there were no significant differences regarding work leave, pension application, or professional education.

CONCLUSIONS

Opioid use appears to be more closely related to psychological factors and single social determinants of pain than to somatic factors.

The Pain-to-Well-Being Relationship in Patients Experiencing Chronic Orofacial Pain

Introduction: Orofacial pain features may negatively influence a person's well-being and vice versa. Some aspects of well-being can be measured with axis II instruments that assess patients' psychosocial and behavioral status. The aim of this study was to investigate associations between pain features and psychosocial variables as indicators of well-being. Materials and Methods: Seven hundred ninety-nine anonymized datasets collected using the Web-based Interdisciplinary Symptom Evaluation (WISE) of patients reporting to the Interdisciplinary Orofacial Pain Unit, University of Zurich, between March 19, 2017 and May 19, 2019, were analyzed. Pain features including intensity, number of locations, impact, and duration were evaluated. Psychometric measures assessed pain-related catastrophizing and disability, illness perception, distress, anxiety, depression, injustice experience, dysmorphic concerns, and insomnia. Results: Most patients were between 30 and 59 years old (58.3%), female (69.8%), working (66.0%), and experienced pain for more than 6 months (68.5%). Pain intensities were higher in women than men and higher in disabled than working patients. Scores indicating elevated stress and depression were also observed in disabled patients. The sample prevalence rates of clinically relevant axis II instrument scores were as follows: Graded Chronic Pain Scale for the Head (GCPS-H), 27%; Patient Health Questionnaire 4 (PHQ4), 21%; PHQ9, 21%; Pain Catastrophizing Scale (PCS), 20%; General Anxiety Disorder 7 (GAD7), 15%; Insomnia Severity Index (ISI), 15%; Injustice Experience Questionnaire (IEQ), 14%; GCPS for the Body (GCPS-B), 13%; PHQ for Stress (PHQstr), 6%; and Dysmorphic Concern Questionnaire (DCQ), 2%. Noteworthy results of correlation analysis of the clinically relevant axis II scores and pain measures were as follows: the PHQstr had moderate associations (0.34-0.43) with the sum of pain intensity at rest and during function, number of pain locations, and typical pain intensity. The IEQ scores were moderately associated with typical pain intensity at 0.39. The DCQ scores were moderately associated with pain extension at 0.41. Conclusions: Moderate correlations of certain pain and well-being measures were found in patients reporting clinically relevant stress, injustice experience, and dysmorphic concern, all of which reflect impaired well-being. PHQ4 is suitable for routine distress screening in the clinical setting.

[Validation of the German-language version of the Injustice Experience Questionnaire (IEQ) in five outpatient clinics]

INTRODUCTION

Occupational and social rehabilitation can be influenced by perceived injustice that results from pain. Currently, the Injustice Experience Questionnaire (IEQ), the tool most commonly used to assess perceived injustice, is not available in German. The aim of this study was the validation of the German-language version of the IEQ.

MATERIALS AND METHODS

The validation of the IEQ was carried out via a web-based survey. For this purpose, participants completed the IEQ and construct-related scales analogous to the original study Tampa Scale of Kinesiophobia (TSK), Depression scale of the Depression Anxiety and Stress Scales (D-DASS), Pain Disability Index (PDI), and McGill Pain Questionnaire (MPQ). In addition, the participants completed questions on their socioeconomic status and on the cause of their pain, taken from the German Pain Questionnaire.

RESULTS

Of 223 respondents, 134 (60.1%) returned a completed questionnaire and were included in the study. In all, 26.1% of participants reported suffering from pain resulting from accidents. None of the reviewed one- to three-factor solutions for the IEQ's structure achieved a good model fit. The best results were found for a two-factor solution, whereby the exploratory factor analysis revealed almost all items loaded highly on both factors and the confirmatory factor analysis showed high correlations between the factors. These findings are consistent with previous studies. The IEQ correlated highly and significantly with the other psychological instruments. There were no floor or ceiling effects. Cronbach's α for the German IEQ version was 0.93 and thus attests a high level of internal consistency.

CONCLUSION

The analyses attest the excellent psychometric properties of the German translation of the IEQ and so the German-language version of the IEQ can be used as a validated questionnaire to screen for perceived injustice.