Neck pain – clinical course and pain trajectories

Neck pain is very common and costly to both society and individuals. Knowing how neck pain progresses over time could improve our understanding as well as aid in pain management. Although prognosis is mostly favorable in the short term, studies on the clinical course of low back pain show that a large group of patients experience persistent and recurrent pain. However, there are few studies on neck pain. In this thesis, we investigated if neck pain patients could be grouped according to the same trajectory definitions identified for low back pain. For 1 year, 1476 patients with neck pain in chiropractic practice answered weekly SMS with questions regarding number of days with pain and pain intensity the past week. Based on the SMS responses, we applied the trajectory definitions and found that they fit readily to our cohort. Most patients were classified as either persistent fluctuating or episodic, which is similar to findings on low back pain. We also assessed to what extent patients shifted from one trajectory to another in quarterly periods and found that 70% of patients experienced a stable trajectory. Lastly, we explored if patients could identify retrospectively their own pain trajectory through a novel method using illustrations of common trajectories (visual trajectories). Overall, we found a general resemblance between the patients’ selected visual trajectory and their 1-year clinical course and trajectory definition (based on SMS data). However, there were large individual variations among patients within each visual trajectory. In particular, patients with mild pain and episodic pain were less able to identify a visual trajectory that most reflected their actual clinical course. Thus, these results may be influenced by recall bias. Our results challenge the concept of ‘chronic pain’ and provide insights into how individual patients report their clinical course of neck pain, both prospectively and retrospectively