Padua FG, et al. - For diagnosing periprosthetic joint infection (PJI), a multi-step process is followed, that involves various tests including erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP). Given the nonspecificity of the latter two tests and substantial effect of demographic characteristics, including age, gender, race, and BMI, on them, researchers here examined the effect of these variations on the diagnostic utility of serological markers for PJI. From institutional databases, they assessed patients undergoing revision arthroplasty between 2010-2018, in whom preoperative serum ESR and CRP was performed. Findings revealed an increase in the value of ESR by age; the value was higher in females and cases from African American race. They indicated no significant differences in value of CRP amongst the demographic factors, although there was a slight positive trend with respect to age. Significant effect of the variation in inflammatory markers on the sensitivity, specificity, and accuracy of ESR and CRP for PJI diagnosis, was observed. Based on findings, they emphasize understanding the variation in the accuracy of diagnostic tests by demographic factors that may allow physicians to avoid subjecting patients to unnecessary additional testing and reach more accurate diagnoses of PJI.