Background and objective: Our goal was to validate the Spanish version of the Brief Pain Inventory (BPI) questionnaire used to measure the intensity of oncological pain and its impact on activities of daily living in patients with cancer.
Patients and method: Patients with oncological pain were consecutively included in the study. These patients filled up the Spanish version of the BPI questionnaire (CBD) and the Rotterdam Symptom Checklist (RCSL) during the inclusion visit and again after 3-5 days (patients with clinically stable oncological pain) or after one month (patients with unstable oncological pain).
Results: 126 patients were assessed; 85.1% of them had suffered some episode of irruptive pain 24 hours prior to their inclusion in the study. 86.5% of patients fully completed the questionnaire. The CBD showed mild to moderate correlations with the patients perception of pain severity and with the presence of tumor dissemination. The <<psychological symptoms>> dimension of the RCSL displayed the highest correlation with the dimensions of the BPI (<<pain intensity>> and <<interference in activities of daily living>>). The internal consistency and the test-retest reliability between dimensions were good (0.87 and 0.89) and low to moderate (0.53 and 0.77), respectively. The CBD questionnaire was found to be a tool capable of detecting changes in pain intensity. The changes observed in the two CBD dimensions between study visits fairly reflected the patients perceived changes in pain intensity.
Conclusions: The Spanish version of BPI is valid for measuring the intensity of oncological pain and its impact on activities of daily living in conditions of usual clinical practice.