RESUMO
INTRODUCTION AND BACKGROUND: Assessment of breakthrough pain is essential for adequate management of cancer pain. The Breakthrough Pain Assessment Tool (BAT) has been proven to be a brief, multidimensional, and reliable questionnaire for the assessment of breakthrough cancer pain (BTCP). Currently, there are no validated instruments in Spanish that allow assessing BTCP. OBJECTIVES: The objective of this study was to validate the Breakthrough Pain Assessment Tool - Spanish (BAT-S) version of the BAT in adult patients with cancer. METHODS: The BAT-S was tested in a prospective observational study conducted in adult patients with cancer-related pain and treated in a comprehensive cancer center in Mexico. We conducted a forward-backward translation and cross-cultural equivalence test in the Spanish language. The psychometric properties in patients with cancer were assessed using factor analysis, reliability, and validity. To assess reliability, the Kappa test and the intra-class correlation coefficient were used. For consistency, Cronbach's alpha test was used. RESULTS: Seventy patients participated in the study; 140 questionnaires were analyzed. The Spanish translation was well accepted by participants. Reliability was comprised between 0.746 for "use of analgesics" and 1.00 for "pain location." Thirteen of the 14 items had values above 0.8, and 12 above 0.9. Cronbach´s alpha coefficient was 0.7. CONCLUSION: This study confirms that BAT-S is a valid and reliable questionnaire to assess breakthrough pain in Mexican patients with cancer. This newly validated tool may be used to facilitate clinical management of primarily Spanish-speaking patients with breakthrough cancer pain. KEY MESSAGE: This study describes a prospective observational study to assess the validity and reliability of the Breakthrough Pain Assessment Tool in its Spanish version. The results support the use of this newly validated tool to facilitate clinical management of primarily Spanish-speaking patients with breakthrough cancer pain.