Red Cell Distribution Width: Commonly Performed Test Predicts Mortality in Primary Total Joint Arthroplasty

Area of Science:

• Orthopedic Surgery
• Hematology
• Biostatistics

Background:

• Mortality following total joint arthroplasty (TJA) is influenced by patient comorbidities.
• Red Cell Distribution Width (RDW) measures red blood cell size variation and is a readily available clinical test.
• The predictive value of RDW, in conjunction with comorbidity indices, for post-TJA mortality requires further investigation.

Purpose of the Study:

• To evaluate the utility of Red Cell Distribution Width (RDW) in predicting 1-year mortality after total joint arthroplasty (TJA).
• To assess whether combining RDW with established comorbidity indices, such as the Charlson Comorbidity Index (CCI), enhances mortality prediction.
• To identify independent predictors of 1-year mortality in patients undergoing TJA.

Main Methods:

• A retrospective analysis of 30,437 primary TJA cases from a single institutional database.
• Collection of patient demographics including age, gender, BMI, pre-operative hemoglobin, RDW, and CCI.
• Statistical analysis using bivariate associations, multivariate regression, and Receiver Operating Characteristic (ROC) curves to compare predictive performance of RDW and CCI alone and in combination.

Main Results:

• RDW, anemia, CCI, and age were significantly associated with increased 1-year mortality.
• RDW, CCI, age, and male sex emerged as independent risk factors for 1-year mortality.
• The combination of RDW and CCI demonstrated superior predictive accuracy (AUC=0.76) compared to RDW (AUC=0.68) or CCI (AUC=0.66) alone.

Conclusions:

• Red Cell Distribution Width (RDW) is a valuable parameter for predicting 1-year mortality after TJA.
• Combining RDW with the Charlson Comorbidity Index (CCI) significantly improves the accuracy of mortality risk prediction in TJA patients.
• This combined approach offers a more robust tool for risk stratification and patient management following TJA.