Validation of the Japanese version of Algoplus® for the assessment of acute postoperative pain in older patients with cancer.

Aim: This study aimed to validate a Japanese version of the Algoplus® tool by assessing postoperative pain in older Japanese patients with cancer and examining the scale's psychometric properties.

Methods: After translating Algoplus® into Japanese, we conducted a cross-sectional study of patients aged 65 years or older who underwent surgery to remove malignant tumors. Two registered nurse-certified investigators used the Numerical Rating Scale, the Japanese version of Algoplus®, and the Japanese version of the Abbey Pain Scale before and after analgesic use on postoperative days 3 and 5 to evaluate response to pharmacologic therapy. Validity was tested by a correlation analysis between the Japanese version of Algoplus®, two pain scales, and nine hypotheses related to demographic variables and surgical invasions. The Kuder-Richardson-20 test and Cohen's Kappa coefficient were used for internal consistency and inter-rater reliability, respectively.

Results: The total score of the Japanese version of Algoplus® showed strong to moderate correlations with the two pain scales. Demographic characteristics were not associated with the total score of the Japanese version, but significant correlations with operative time and postoperative analgesia administration existed. The scale demonstrated good internal consistency (Kuder-Richardson-20 α: .70) and inter-rater reliability (Kappa coefficient .72). The total score of the Japanese version decreased significantly after analgesic use in both postoperative assessments.

Conclusions: The Japanese version of Algoplus® is a reliable and valid instrument for nurses to easily assess acute postoperative pain in older Japanese patients with cancer and shows good responsiveness for detecting the change in pain status.