Pain in the three spinal regions: the same disorder? Data from a population-based sample of 34,902 Danish adults

BACKGROUND: Studies of back pain are typically based on the assumption that symptoms from different parts of the spine are distinctive entities. Recently, however, the assumption that back pain is a site-specific disorder has been challenged, suggesting that localized back pain should be seen as part of a general musculoskeletal syndrome. OBJECTIVES: To describe and compare the patterns of reporting of pain and consequences of pain in the three spinal regions. METHODS: In all, 34,902 (74%) twin individuals representative of the general Danish population, aged 20 to 71, participated in a cross-sectional nation-wide survey. Identical questions from the Standardised Nordic Questionnaire for each of the three spinal regions were used for lumbar, mid-back and neck pain respectively: Pain past year, pain ever, radiating pain, and consequences of back pain (care-seeking, reduced physical activities, sick-leave, change of work/work duties and disability pension). The relative prevalence estimates of these variables were compared for the three spinal regions. RESULTS: The relative proportions of individuals with pain ever, who also reported to have had pain in the past year varied between 75% and 80%, for the three spinal regions. The proportions of individuals with pain in the past year and for various pain durations were also very similar. Regardless if pain was reported in the lumbar, thoracic or cervical regions, the proportions of individuals reporting radiating pain were equally large. The relative number of consequences was the same across the spinal regions, as were the relative proportions of each these consequences. However, low back pain resulted more often in some kind of consequence compared to the consequences of pain in the neck and mid back. CONCLUSIONS: Back pain and its consequences share many characteristics and may, at least in a general population, be regarded as the same condition regardless of where the pain happens to manifest itself. However, because some exceptions were noted for the lumbar spine, separate entities for a smaller group of individuals with back pain cannot be ruled out.