RA Among the Preop Predictors of Hospital Readmission Following THR

THA x ray
THA x ray
The use of a postoperative risk stratification model can serve to reduce the costs associated with hospital readmission by identifying patients with specific risk factors.

Certain risk stratification models can reliably identify patients who are at higher risk for hospital readmission following total hip replacement (THR), allowing for implementation of specific protocols to target these at-risk patients, according to research published in JAMA Surgery. Rheumatoid arthritis (RA) was identified as a preoperative predictor of hospital readmission.

To identify and verify a scale that can predict which patients are more likely to necessitate hospital readmission after THR, Ronald Chamberlain, MD, MPA, and colleagues retrospectively analyzed discharge data from patients enrolled in the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality during the years of 2006-2011.   Data from 268,518 patients from New York and California was utilized in the first cohort used to derive parameters for the scale (derivation cohort), while data from 153,560 patients from Florida and Washington was used to validate the created scale (validation cohort).

The authors then abstracted demographic and clinical data from the patients undergoing THR in the derivation cohort, analyzing factors previously reported in the literature as being associated with higher rates of 30-day readmission.  These risk factors were then reassessed in the validation cohort. The resulting data was used to develop the “Readmission After Total hip Replacement Risk Scale”.

The observed 30-day hospital readmission rate was 5.89% in the derivation cohort and 5.82% in the validation cohort. The most common reasons for hospital readmission were surgical site infection and postoperative complications related to the implanted hardware.

The risk factors identified as being associated with hospital readmission following THR were:

Age > 71 years OR 1.83 95% CI, 1.77-1.89
Rheumatoid arthritis OR 1.19 95% CI, 1.16-1.27
Re-operative (revision) Total Hip Replacement OR 1.82 95% CI, 1.75-1.90
Obesity OR 1.15 95% CI, 1.09-1.21
Congestive Heart Failure OR 1.49 95% CI, 1.38-1.61
Hypertension OR 1.17 95% CI, 1.12-1.21
Uncomplicated Diabetes Mellitus OR 1.21 95% CI, 1.16-1.27
Anemia OR 1.19 95% CI, 1.15-1.25
Fluid and electrolyte balance OR 1.21 95% CI, 1.14-1.27
History of chronic pulmonary disease OR 1.33 95% CI, 1.27-1.39
African American race OR 1.23 95% CI, 1.15-1.31
History of liver disease OR 1.57 95% CI, 1.39-1.77
Coagulopathy OR 1.19 95% CI, 1.08-1.32
Income in first quartile OR 1.18 95% CI, 1.12-1.24

Summary and Clinical Applicability

This study validated certain risk factors associated with an increased 30-day hospital readmission rate post-THR, including RA. A scale was then developed utilizing certain risk factors to stratify which patients would be at a higher risk for hospital readmission following THR..

“Risk-stratification models, such as the Readmission After Total Hip Replacement Risk Scale, can identify high-risk patients for readmission and permit implementation of patient-specific readmission-reduction strategies to reduce readmissions and health care expenditures”, the authors concluded.

The limitations of the data utilized in this study to create the risk stratification scale included possible coding errors passed into the data that was used to analyze the included cohorts and incomplete readmission data on some of the patients from the inpatient database.


Siracuse BL, Chamberlain RS. A Preoperative Scale for Determining Surgical Readmission Risk After Total Hip Replacement. JAMA Surg. 2016; Mar 9. doi: 10.1001/jamasurg.2016.0020. [Epub ahead of print]