Psychometric properties of the Persian version of the brief illness questionnaire in Iranian with non-specific chronic neck pain.

INTRODUCTION: The Brief Illness Perception Questionnaire (BIPQ) is an instrument for assessing the illness perception. Illness perception varies between individuals based on their health status. There is no study that assess the psychometric properties of the Persian version of BIPQ in neck pain patients. The goal of this study was to evaluate the reliability, construct validity, and exploratory factor analysis of the Persian BIPQ in individuals with non-specific chronic neck pain. METHODS: This is a cross-sectional study in which 123 individuals with non-specific chronic neck pain participated. 60 participants examined after 7 days for testing reliability. Reliability was assessed by intra-class correlation coefficient, standard error of measurement, and minimal detectable change. For assessing construct validity and item-total correlation, correlation tests were used. Also, exploratory factor analysis was done to assess the factor structure of the BIPQ. RESULTS: Exploratory factor analysis' results showed that there were 2 factors with Eigenvalues >1. Factor 1 included "identity", "consequence", "timeline", and "emotional response". Factor 2 consisted of "coherence" and "treatment control". The intra-class correlation coefficient and the cronbach's alpha for the total score was 0.8 and 0.86 respectively. Results of correlation tests showed an acceptable construct validity except with SF-12 mental component. Item-total correlation tests demonstrated that the correlations were above 0.3 for all subscales except for "treatment control" and "coherence". CONCLUSION: BIPQ has an acceptable properties to assess illness perception in individuals with non-specific chronic neck pain. The results of exploratory factor analysis and item-total correlation confirmed that 2-subscale version is more acceptable.

Translation, reliability, and validity of the avoidance endurance questionnaire in Iranian subjects with chronic non-specific neck pain.

BACKGROUND: To cross-cultural adaptation, test-retest reliability, construct validity of the Persian version of avoidance endurance questionnaire (AEQ) in Iranian subjects with chronic nonspecific neck pain (CNSNP). OBJECTIVE: The AEQ differentiates endurance responses [ER; positive mood scale (PMS), thought suppression scale (TSS), pain persistence behavior scale (PPS), humor/distraction scale (HDS), and behavioral endurance scale (BES) from fear-avoidance responses (FARs; anxiety/depression scale (ADS), catastrophizing scale (CTS), helplessness/hopelessness scale (HHS), avoidance of social activities scale (ASAS), and avoidance of physical activities scale (APAS)]. METHODS: One hundred and thirty persons with CNSNP took part in this psychometric study. The translation process was done by Beaton guideline. Test-retest reliability and internal consistency were presented by intraclass coefficient (ICC) and Cronbach's alpha, respectively. The construct validity was measured by the correlation between AEQ subscales and the Short-form health survey (SF-12), visual analog scale (VAS), fear-avoidance beliefs questionnaire (FABQ), pain catastrophizing scale (PCS), Tampa scale for kinesiophobia (TSK), and neck disability index (NDI). RESULTS: The Cronbach's alpha of all FAR and ER subscales was more than 0.7, and ICCs of all FAR subscales were more than 0.8 and ICCs of ER subscales were reported between 0.59 and 0.86. The correlation between FAR subscales and TKS, FABQ, FABQ.PA, FABQ.W, NDI, PCS, and VAS were the limit between -0.239 and 0.199, and the association between ER subscales and the abovementioned questionnaires was the limit between 0.179 and 0.644. CONCLUSIONS: The Persian version of AEQ showed acceptable reliability (test-retest, internal consistency) for FAR and ER, and also the construct validity was acceptable. The Persian version of AEQ had acceptable psychometric properties, thus it is a good instrument to identify fear avoidance and ERs of the pain.