Iranian Brief Pain Inventory: Validation and Application in Elderly People With Cancer Pain

Abstract Context Cancer is a major health problem in the elderly, and pain is one of the most common symptoms among older patients with cancer. Sufficient pain treatments depend on the accuracy of the pain assessment tool. Objectives This study aimed to assess the psychometric properties of the Iranian version of the Brief Pain Inventory (BPI-IR) among elderly individuals with cancer. Methods This validation study was conducted with 368 people aged 60+ years old who were undergoing oncology treatments. The BPI-IR was applied to the elderly participants through face-to-face interviews. Reliability of the BPI-IR was evaluated using Cronbach's alpha coefficient and intraclass correlation coefficient between test-retest scores. Criterion validity was determined by calculating the Spearman's correlation coefficient between scores on the BPI-IR and those on the SF-36 physical function, Activities of Daily Living, Instrumental Activities of Daily Living, Center for Epidemiological Studies Depression, Patient Pain Questionnaire, and Symptom Distress Scale. Construct validity of the BPI-IR was evaluated using exploratory factor analyses. Results Cronbach's alpha coefficient was calculated to be 0.94, and the intraclass correlation coefficient between twice the BPI-IR scores over two weeks obtained was 0.89. There were moderate-to-high correlations between the BPI-IR and the Patient Pain Questionnaire ( r  = 0.886), Symptom Distress Scale ( r  = 0.492), SF-36 physical function ( r  = 0.554), and Center for Epidemiological Studies Depression ( r  = 0.608). Two factors were extracted in exploratory factor analyses, and they explained 73.86% of total variance. Conclusion The BPI-IR is a reliable and valid tool for assessing pain among older adults with cancer.