A targeted literature review of the burden of illness for spine-related neuropathic pain in Japan.

Background: Neuropathic pain (NeP) is pain provoked by damage or disease in the nervous system and about one in three Japanese patients with spinal disorders are highly likely to have NeP. The humanistic and economic burden of illness (BOI) of spine-related NeP represents unmet medical needs that should be addressed. The purpose of this targeted literature review was to synthesize the available evidence on the BOI of spine-related NeP in Japanese patients.

Methods: PubMed and ICHUSHI were searched for relevant studies published between January 2010 and December 2020, in English or Japanese. The population included patients with one or more of prespecified spinal disorders and NeP, and outcomes of interest were data related to humanistic or economic burden.

Results: Out of 32 studies that assessed the BOI of spine-related disorders in Japan, only six specifically assessed spine-related NeP. Among these studies, five different validated questionnaires were used to measure humanistic burden. Spine-related NeP was consistently shown to be related with a poorer health-related quality of life and higher levels of anxiety and depression compared to the general population as well as patients with nociceptive pain. No articles directly evaluating economic burden were identified in this search, so an exploratory analysis was conducted. Reduction in work productivity by people experiencing spine-related NeP in the whole of Japan were estimated to total JPY 172,266,780,480 per year.

Conclusions: The humanistic burden of spine-related NeP on Japanese patients is considerable, not only physically but also mentally. Exploratory analysis of the economic burden illustrates the possibility of substantial societal costs associated with NeP. In order to better understand the depth of BOI and the unmet medical need caused by spine-related NeP, further studies on real-world outcomes are recommended.