Reporting and Analyzing Demographics in the Journal of Arthroplasty: Are We Making Progress?

Demographic factors, including age, sex, body mass index (BMI), race, and ethnicity have great effects on the outcomes of patients undergoing total joint arthroplasty. A portion of this data is included in nearly every study, but the completeness with which it is reported is variable. The purpose of this study is to investigate the frequency at which demographic information is reported and analyzed through formal statistical methods in randomized controlled trials (RCTs) published in the Journal of Arthroplasty (JOA).

A systematic review was conducted of RCTs published in JOA between 2015 and 2019. For each study, we determined if age, sex, weight, height, BMI, race, and ethnicity were reported and/or analyzed. The overall frequency was assessed, along with the rates of reporting by individual year. Studies were evaluated using Cochrane risk-of-bias tool.

Age (96.7%), sex (96.7%), and BMI (80.4%) were reported by the majority of studies. There was very little information provided regarding race (6.2%) and ethnicity (3.8%); although both were reported at the highest frequency in 2019, the final year of articles reviewed. Sex was the most frequently analyzed variable at 11.5%. Only 1 study (0.5%) analyzed ethnicity and no studies analyzed race.

Although age, sex, and BMI are reported at a high rate, RCTs published in JOA rarely reported information on patient race and ethnicity. Demographics were infrequently included as part of statistical analysis. The importance of this information should be recognized and included in the analysis and interpretation of future studies.