The Norwegian version of the American pain society patient outcome questionnaire: reliability and validity of three subscales

Aims and objectives. To examine some psychometric properties of the Norwegian version of the American Pain Society's Patient Outcome Questionnaire (APS-POQ-N). Background. This study is part of an investigation of Norwegian orthopaedic surgical patients, where the overall aim is to evaluate the quality of postoperative pain management. Therefore, an adequate questionnaire on the quality of postoperative pain management was needed. Methods. The sample included 114 orthopaedic postoperative patients. The instrument consists of three main subscales, namely the modified Brief Pain Inventory (modified BPI subscale), the subscale on satisfaction with pain management (Satisfaction subscale) and the subscale on beliefs about pain management (Beliefs subscale), together with six single items about pain management. The reliability of these three main subscales was estimated using Cronbach's alpha coefficients and the construct validity was evaluated using principal-axis factor analysis with oblimin rotation. Results. Face and content validity of the APS-POQ-N were satisfactory, while the modified BPI and the Beliefs subscales showed acceptable internal consistency but the Satisfaction subscale did not. Factor analyses yielded a three-factor solution for the modified BPI, a one-factor solution for the Satisfaction subscale and a two-factor solution for the Beliefs subscale. Conclusions. The APS-POQ-N appears, in general, to be an acceptable method of evaluating postoperative pain management in orthopaedic postoperative patients. However, the alpha value of the Satisfaction subscale was low, and thus the subscale is not recommended for this purpose. Relevance to clinical practice. Reliable and valid instruments are important when performing clinical research. This instrument is applicable as an indicator of quality of postoperative pain management in clinical practice and research.