Few Randomized Controlled Trials in Spine Surgery in the United States Include Sociodemographic Patient Data: A Systematic Review

Introduction:The importance of sociodemographic factors such as race, education, and income on spine surgery outcomes has been well established, yet the representation of sociodemographic data within randomized controlled trials (RCTs) in spine literature remains undefined in the United States (U.S).Methods:Medical literature was reviewed within PubMed for RCTs with "spine"in the title or abstract published within the last 8 years (2014 to 2021) in seven major spine journals. This yielded 128 results, and after application of inclusion criteria (RCTs concerning adult spine pathologies conducted in the U.S), 54 RCTs remained for analysis. Each article's journal of publication, year of publication, and spinal pathology was recorded. Pathologies included cervical degeneration, thoracolumbar degeneration, adult deformity, cervical trauma, and thoracolumbar trauma. Sociodemographic variables collected were race, ethnicity, insurance status, income, work status, and education. The Fisher's exact test was used to compare inclusion of sociodemographic data by journal, year, and spinal pathology.Results:Sociodemographic data were included in the results and in any section of 57.4% (31/54) of RCTs. RCTs reported work status in 25.9% (14/54) of results and 38.9% (21/54) of RCTs included work status in any section. Income was included in the results and mentioned in any section in 13.0% (7/54) of RCTs. Insurance status was in the results or any section of 9.3% (5/54) and 18.5% (10/54) of RCTs, respectively. There was no association with inclusion of sociodemographic data within the results of RCTs as a factor of journal (P = 0.337), year of publication (P = 0.286), or spinal pathology (P = 0.199).Discussion:Despite evidence of the importance of sociodemographic factors on the natural history and treatment outcomes of myriad spine pathologies, this study identifies a surprising absence of sociodemographic data within contemporary RCTs in spine surgery. Failure to include sociodemographic factors in RCTs potentially bias the generalizability of outcome data.