Preoperative Serum Albumin Levels Predict Treatment Cost in Total Hip and Knee Arthroplasty

Figures

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  Fig. 1. Patient selection criteria. Of 4,763 initial patients, 3,785 (79.5%) met selection criteria. TKA: total knee arthroplasty, THA: total hip arthroplasty, BMI: body mass index, Hb: hemoglobin.

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  Fig. 2. Total direct costs by primary (A) and revision (B) total hip arthroplasty (THA) and total knee arthroplasty (TKA). At a level of *p < 0.05, hypoalbuminemia was associated with significantly increased costs for primary THA ($17,735 vs. $14,031, p < 0.001) and primary TKA ($17,815 vs. $13,184, p < 0.001) relative to those with serum albumin > 4.5 g/dL. This trend persisted for revision procedures, as those with hypoalbuminemia had higher costs for revision THA ($32,275 vs. $19,818, p < 0.001) and revision TKA ($23,640 vs. $18,704, p < 0.001). A serum albumin level of 3.5–4.0 g/dL also had significantly higher costs relative to serum albumin > 4.5 g/dL for both primary and revision THA procedures, as well as revision TKA procedures.

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  Fig. 3. Additional cost of each serum albumin category by primary or revision procedure relative to serum albumin > 4.5 g/dL. Multivariable regressions for both primary and revision procedures accounted for age, body mass index, hemoglobin, glomerular filtration rate, and joint (hip or knee). At a level of *p < 0.05, hypoalbuminemia was associated with significantly increased costs for both primary (average, $3,446; p < 0.001) and revision (average, $4,322; p = 0.034) procedures. Furthermore, serum albumin 3.5–4.0 g/dL was also associated with an average cost increase of $3,787 (p = 0.008) relative to those with serum albumin > 4.5 g/dL.

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  Fig. 4. Length of stay (LOS) by total hip arthroplasty (THA) and total knee arthroplasty (TKA). (A) At a level of *p < 0.05, hypoalbuminemia was associated with significantly increased LOS for primary THA (4.0 vs. 2.6 days, p < 0.001) and primary TKA (4.2 vs. 2.8 days, p < 0.001) relative to those with serum albumin > 4.5 g/dL. (B) This trend persisted for revision procedures, as those with hypoalbuminemia had higher LOS for revision THA (7.3 vs. 3.6 days, p < 0.001) and revision TKA (4.3 vs. 2.7 days, p < 0.001). For both THA and TKA primary procedures, all serum albumin classes lower than serum albumin > 4.5 g/dL were associated with significantly longer lengths of stay. For TKA revision procedures, both serum albumin 3.5–4.0 g/dL and 4.0–4.5 g/dL were associated with significantly increased LOS.