Translation and validation of the Norwegian version of the Injustice Experience Questionnaire

Abstract

Objectives Perceived injustice is a theoretical construct comprising elements of loss, attribution of blame, and sense of unfairness. Patients with chronic pain often report high levels of perceived injustice, which can have negative impact on physiological and psychosocial aspects and treatment outcome. The Injustice Experience Questionnaire (IEQ) is a self-report 12-item questionnaire that shows good reliability and validity in patients with chronic pain. This study aimed to translate, validate, and expand the use of the Norwegian Injustice Experience Questionnaire (IEQ-N) to a chronic pain population. Methods A mixed-method approach was used to translate and validate the IEQ-N. It was forward-back translated, linguistically validated, and culturally adapted. Individual cognitive debriefing interviews (n=7) and a focus group interview (n=9) was used to explore the patients’ experience with- and understanding of the questionnaire. Statistical descriptive, correlational, factor- and regression analyses were used to investigate the IEQ-N validity, reliability, and factorial structure in a large registry sample (n=3,068) of patients with chronic pain. Results Patients with chronic pain found the IEQ-N relevant. Registry analyses supported that the IEQ-N had a one-factor structure. The internal consistency was high (Chronbach’s alpha=0.92). The construct validity was good, with moderate to strong significant univariate correlation (r=0.29–0.71) (p<0.05) between perceived injustice and related constructs of pain catastrophizing, pain severity, disability, psychological distress, and quality of life. Perceived injustice contributed with significant but small unique variance to pain-related factors (i.e., pain intensity, pain-related disability, psychological distress), but the additional contribution beyond pain catastrophizing was small (0.2–6.7%) (p<0.05). Conclusions Patients in the study found the questionnaire relevant for their situation, and easy to understand. This study provides a reliable and valid Norwegian tool to assess perceived injustice in patients with chronic pain. Ethical committee number REK sør-øst, 2016/1942.

Perceived Injustice and Anger in Fibromyalgia with and without Comorbid Mental Health Conditions

“…In the patient groups, the strong correlations between the IEQ and PCS replicate findings both in the IEQ's initial development 7 and more recently (ranging from 0.65 to 0.75). 12,13,15,19,64,66 At the same time, these studies indicated a tendency of the IEQ to explain additional variability above and beyond PCS. In the current study (Supplemental Materials, Supplemental Digital Content 1, http://links.lww.com/ CJP/B83, Tables S1-S3, Supplemental Digital Content 2, http://links.lww.com/CJP/B84, Supplemental Digital Content 3, http://links.lww.com/CJP/B85, Supplemental Digital Content 4, http://links.lww.com/CJP/B86), IEQ scores explained additional pain variability above and beyond PCS only within specific patient groups and pain measures, whereas PCS explained additional variability above and beyond IEQ in only one such case.…”

“…Although some validations of the IEQ have employed Confirmatory Factor Analysis, 64,68,69 we opted for PCA in line with the many other IEQ validation studies. 7,19,[65][66][67] Given the varied findings of factor analyses within these papers, we concluded that the more exploratory PCA was preferable to a confirmatory method. Reliability was assessed using Cronbach alpha, providing a measure of the internal consistency of the questionnaire items.…”

“…In validating our Hebrew version of the IEQ, we confirmed a 1-factor structure for all 12 items with excellent reliability. Previous validations and translations of the IEQ have yielded mixed results regarding a 2-factor [64][65][66]69 versus 2-factor 19,67,68 structure, although the latter consistently reports very high overlap between the components. As such, our findings support Sullivan et al's 7 original conception that the IEQ might be best construed as a complex but unitary construct, with the theoretical subscales not deriving statistically separate components.…”

“…To date, the IEQ has been validated in multiple languages. 19,[64][65][66][67][68][69] We further aimed to translate and validate a Hebrew version of the IEQ, confirming its structure using factor analysis and measuring internal consistency using Cronbach alpha. In line with previous findings, we hypothesized a linear trend such that PI (as measured by the IEQ), state and trait anger, and measures of anxiety, depression, and pain catastrophizing will be greater in FM+A/D compared with FM-A/D, RA, and PFCs, respectively.…”

Pre- and post-operative psychological interventions to prevent pain and fatigue after breast cancer surgery (PREVENT): Protocol for a randomized controlled trial

“…Respondents are asked to rate their experience of injustice on a 5-point scale ranging from 0 (not at all) to 4 (all the time) [73]. The scale has been translated and validated in Norwegian [74]. In the PREVENT trial we slightly adjusted the wording in the scale instruction to make it fit patients diagnosed with breast cancer.…”