RESUMO
The need for a standard instrument to assess pain in cancer patients is universally accepted. The aim of this study was to assess the psychometric properties of the Persian version of the Brief Pain Inventory [BPI] on a sample of Iranian Cancer patients. This cross-sectional study was conducted in Kerman on a sample of 211 cancer patients. At first the questionnaire was translated and back translated through standard methods. The face validity of the inventory was examined on 15 individuals with diverse educational levels to assess the comprehensibility and acceptability by the patients. The construct validity of the instrument was assessed by both exploratory and confirmatory factor analysis. The internal consistency was analyzed by Cronbach's alpha coefficient and item scale correlation. The response rate was 96%. Nearly 52% were female. The Persian version was compatible with the original version. The Kaiser's measure of sampling adequacy [MSA] before factor extraction of the questionnaire was 0.87, which indicated an acceptable factorability of the statements. The construct validity of the questionnaire was confirmed by exploratory and confirmatory factor analysis. The measures of internal consistency were in an acceptable level. Cronbach`s alpha for the whole questionnaire [11 items] was 0.87 and it was 0.87 and 0.89 for the intensity and reactive dimensions, respectively. The Persian version of BPI was a reliable and valid measure to assess pain in cancer patients