INTRODUCTION: Determining the nature of pain is essential in evaluating patients with back pain, and certain types of pain might be useful for reaching clinical diagnosis and selecting appropriate treatment options. The purpose of this study was to classify pain quality in patients with back symptoms, and to examine how the classified subgroups of pain quality related to other patient's findings and background.
METHODS: This study consisted of 92 outpatients with back symptoms including leg pain. There were 45 men and 47 women with a mean age of 55 years. All the patients were asked to multiply choose their pain quality using Short Form McGill Pain Questionnaire that consisted of 15 categories of pain. Cluster analysis was applied to classify the pain categories. The findings and backgrounds among classified subgroups were also compared.
RESULTS: Cluster analysis revealed 3 clusters. Cluster 1 consisted of 44 patients (48%) and had characteristic pain of heavy (66%), aching (41%), cramping (34%) and gnawing (20%). Cluster 2: 28 patients (30%) and that of shooting (68%) and throbbing (60%). Cluster 3: 20 patients (22%) and that of sharp (65%), stabbing (50%) and tender (25%). Male dominant in cluster 3 (74%) and female dominant in cluster 1 (64%) were observed. In cluster 3, leg pain was frequently occurred (45%) and pain during extension was less (74%). The mean age was also younger in cluster 3 (43 years). There was no difference in duration of symptoms, pain during flexion and pain intensity among the 3 clusters.
DISCUSSION: Our results showed that quality of pain in back symptoms were classified into 3 groups, and each group had different patient's background and physical findings. Further studies are needed to confirm how the classified pain quality related to various conservative treatment responses.