IntroductionWe developed the Brief Scale for Psychiatric problems in Orthopaedic Patients (BS-POP) (doctor and patient versions). The present study aimed to proactively verify the factorial validity, internal consistency, criterion-related validity and reproducibility of the BS-POP with regard to chronic low back pain patients.MethodsSubjects comprised 193 chronic low back pain patients. During the first test, the BS-POP, Minnesota Multiphasic Personality Inventory (MMPI), Profile of Mood States (POMS) and 36-Item Short-Form Health Survey version 2 (SF-36 v2) were conducted. In the second test, patients were asked to complete the BS-POP in order to verify BS-POP reproducibility.ResultsFactor analysis demonstrated the factorial validity of the BS-POP, including 1-factor structure. Internal consistency was confirmed by Cronbach’s α reliability coefficients of 0.794 (doctor version) and 0.750 (patient version). Criterion-related validity was confirmed through association with the psychosocial factors of the SF-36, the MMPI, and the POMS. The correlation coefficients for the retests were r = 0.654 (doctor version) and r = 0.719 (patient version), showing reproducibility.DiscussionThe present findings indicate that the BS-POP possesses sufficient reliability regarding computational psychology. The BS-POP constitutes a tool enabling orthopaedists themselves to easily identify psychiatric problems in orthopaedic patients. Further study is required regarding responsiveness.