Incidence of traumatic spinal cord injury worldwide: A systematic review, data integration, and update

OBJECTIVES: This review was designed to update our earlier systematic review which evaluated both published and unpublished evidence on the incidence of traumatic spinal cord injury (TSCI) worldwide. METHODS: We used various search methods including strategic searching, reference checking, searching for grey literature, contacting registries, authors, and organizations requesting unpublished data, browsing related websites, and hand searching key journals. The quality of included studies was evaluated by Joanna Briggs Institute Critical Appraisal Tools. Records published between April 2013 and May 2020 were added to the original systematic review. RESULTS: Overall, 58 resources including 45 papers, 10 SCI registry reports, 1 book, and 2 theses were retrieved. We found TSCI incidence data for eight new countries, which overall shapes our knowledge of TSCI incidence for 49 countries. The incidence of TSCI ranges from 3.3 to 195.4 cases per million (cpm) based on subnational studies and from 5.1 to 150.48 cpm based on national studies. Most of the studies were low quality, lacked consistent case selection due to unclear definition of TSCI and unclear ascertainment methods. CONCLUSIONS: There is an increasing number of publications in the literature focusing on the epidemiologic data of TSCI. The absence of a standard form of reporting TSCI hinders the comparability of data across different data sources. Use of various definitions for TSCI may lead to heterogeneity in reports. Use of sensitivity analyses based on reasonable classification criteria can aid in offering a uniform set of case identification and ascertainment criteria for TSCI.