RESUMO
STUDY DESIGN: Individuals with low back pain were classified by cluster analysis of their responses to the Dallas Pain Questionnaire. These results enabled development of an alternative simple classification tool that yielded results close to those obtained by the cluster analysis. OBJECTIVES: To use the Dallas Pain Questionnaire to classify workers with low back pain, and to develop a practical classification tool for physicians. SUMMARY OF BACKGROUND DATA: The severity of low back pain is important information for patient management. Questionnaires exploring the multidimensional aspect of low back pain have been used to classify individuals with low back pain. The Dallas Pain Questionnaire is a short self-administered questionnaire that explores the functional and emotional aspects of chronic low back pain. It was tested in a population still at work using a simplified scoring system. METHODS: The study included 765 persons with low back pain still at work who completed the self-administered questionnaire. Of these patients, 732 could be classified by cluster analysis according to their answers to the Dallas Pain Questionnaire. A classification tool was developed to categorize them. Using external variables, the groups thus formed were compared. RESULTS: Respondents were classified into four classes: class 1 (minor disability), class 2 (intermediate disability), class 3 (disability for some physical activities), and class 4 (physical disability and emotional disturbance). External pain-related variables were clearly associated with increasing low back pain severity as measured by this classification tool. CONCLUSIONS: The Dallas Pain Questionnaire discriminated between different groups of persons with low back pain. The proposed classification uses a short, simple practical tool to assess different levels of low back pain.
