Validation of the Questionnaire for Symptom Assessment in Pain disorders for Back pain patients (Q-SAP)

Abstract

Background: Previous studies have shown that not only pain intensity but also impairment of quality of life and functionality are important parameters for the evaluation of treatment of chronic low back pain patients. The aim of the study was to validate a specific self-questionnaire for symptom assessment and their influence on quality of life and functionality of chronic low back pain patients (Questionnaire for Symptom Assessment in Pain disorders for back pain patients, Q-SAP). Methods: The self-questionnaire consists of two parts (for back and if applicable leg symptoms) and was tested in 152 chronic low back pain patients with and without radiculopathy. Test–retest reliability, exploratory factor analysis, convergent validity, criterion-related validity and the sensitivity to detect patient reported changes were investigated. Results: The questionnaire showed a good to excellent test–retest reliability. In the factor analysis nociceptive and neuropathic pain components could be separated and the highest convergent validities were shown for the painDETECT, EQ-5D-3L and the FFbH-R. The criterion-related validity showed concordance of QST and the Q-SAP Back for warmth induced pain and numbness. Regarding the sensitivity to patient-reported changes, a moderate correlation was found for both parts of the questionnaire. Conclusions: The Q-SAP was tested as a useful, valid and reliable tool. This new questionnaire records classical nociceptive and neuropathic pain symptoms of chronic low back pain patients depending on their local distribution. Furthermore, the questionnaire records the intensity of these symptoms and their influence on quality of life and functionality and can be used for the evaluation of treatment. Significance: The Q-SAP Back/Leg is a new self-questionnaire for CLBP patients with or without radiating leg pain that precisely assesses neuropathic and nociceptive symptoms. In contrast to other questionnaires, the Q-SAP Back/Leg evaluates not only symptom intensities but also their impact on the patient's quality of life and functionality. Furthermore, this questionnaire requests the symptoms depending on their anatomical distribution.