Interventional pain management focused on zygapophysial joint pain : a health-economic evaluation

Abstract: The pain-system is a central mechanism in our life. Chronic pain is one of the major causes of impaired health-related quality of life according to the World Health Organization’s “Global Burden of Disease”-studies. Zygapophysial joint pain has been shown to account for the pain in 30% - 50% of patients with chronic pain. There are several well-established, evidence-based methods to treat zygapophysial joint pain in the cervical and lumbar regions.This thesis originates from this and starts by exploring whether the treatment of zygapophysial joint pain can improve health-related quality of life. This thesis describes methods for the diagnosis and treatment of zygapophysial joint pain in the thoracic region that can be applied to the treatment of all pain-foci localized to the zygapophysial joints. I show that the health-related quality of life was significantly improved after treatment, and that the clinical methods used for treating thoracic pain were similar to the methods that have been established previously for cervical and lumbar pain.In order to better understand the patients’ experiences we performed qualitative interviews with patients who underwent diagnostic tests and treatments. The overall theme revealed by these interviews was that of empowerment, in which the patients were empowered by the process of diagnostic tests and treatments.The next question was whether the method was cost-effective or not. In the first cost-effectiveness analysis, the patients served as their own controls and we evaluated the results against the limits set by the Swedish national board of health and welfare. The results showed that it was cost-effective in the moderate to low range.Finally, we compared the treatment to the “gold standard” for pain management in Sweden; i.e.pain rehabilitation. We mimicked a randomized controlled trial by using propensity score weighting to compare 254 patients agains 15,357 patients registered in the Swedish National Register of Pain Rehabilitation. The results showed that interventional pain management was cost-effective in the moderate (12 months after treatment) to low (≥24 months after) range whereas pain rehabilitation was in the very high range (after 12 months) and became cost-effective in the high range after 24 months of treatment. Currently, interventional pain management accounts for just 2% of all specialized pain management procedures in Sweden. If this could be increased to 25%, it may be possible to save 106 million SEK annually, while simultaneously gain 14 quality adjusted life years of health. If an interventional pain assessment is performed early in the process, treatable patients could be directed toward interventional treatment and away from interdisciplinary pain management programs, with the potential for further reductions in costs.