Validity and reliability of the Greek version of the Pain Beliefs and Perceptions Inventory for patients with chronic pain

Abstract

Background/aims The Pain Beliefs and Perceptions Inventory has been used widely to evaluate pain perceptions and beliefs of patients with chronic pain. This is a cross-cultural adaptation of the instrument into Greek. The purpose of the study was to investigate: the face and content validity; the factor structure; the concurrent validity; the discriminant validity; and the internal consistency and the test–retest reliability of the Pain Beliefs and Perceptions Inventory for people with chronic pain. Methods A total of 174 patients with chronic low back pain, neck pain and/or pain of limbs lasting for at least 6 months and with a physiotherapy referral participated in the study. Exploratory factor analysis by a principal axis factoring with direct oblimin rotation was chosen to examine the factor structure of the Pain Beliefs and Perceptions Inventory. The concurrent validity was assessed using correlations by Spearman's rho correlation coefficient among the Pain Beliefs and Perceptions Inventory and the Short Form-McGill Pain Questionnaire, the Present Pain Index, the visual analogue scale and the Brief Pain Inventory. The discriminant validity was examined by Spearman's rho correlation coefficient among the Pain Beliefs and Perceptions Inventory and Social Desirability Scale. The reliability of the instrument was examined using Cronbach's α internal consistency coefficients and intraclass correlation coefficients. Results Exploratory factor analysis confirmed the four factor structure of the Pain Beliefs and Perceptions Inventory that explained 66.353% of the total variance. Concurrent validity was determined through examination of correlations between the Pain Beliefs and Perceptions Inventory and other validated constructs (eg Short Form-McGill Pain Questionnaire Affective factor with Total Pain Beliefs and Perceptions Inventory Spearman's rho=0.257, P<0.001, Brief Pain Inventory General Activity and Pain Beliefs and Perceptions Inventory Constancy factor Spearman's rho=0.522, P<0.05, Brief Pain Inventory relations with other people and Pain Beliefs and Perceptions Inventory Constancy factor Spearman's rho=0.512, P<0.05). The discriminant validity of the Pain Beliefs and Perceptions Inventory was confirmed by examining correlations between the Pain Beliefs and Perceptions Inventory with the Marlowe–Crowne Social Desirability Scale. The questionnaire was internally consistent (α=0.89–0.96) and its stability was good (intraclass correlation coefficients=0.73–0.82). Conclusions The Greek translation of the Pain Beliefs and Perceptions Inventory is a reliable and valid instrument to evaluate Greek patients with chronic pain.