A program launched by the CMS penalizes hospitals that readmit joint replacement patients within 90 days of undergoing the procedure. However, there are no models in place to assess those patients’ risk for readmission, according to a recent study.

The Centers for Medicare and Medicaid Services launched the Comprehensive Care for Joint Replacement (CJR) program in April 2016. However, the CJR’s current payment model does not include a risk adjustment method to account for joint replacement patients’ medical complexity or their functional status, according to a media release from Brown University.

In the study, conducted at Brown University and published recently in Arthritis Care & Research, researchers tested the applicability of three risk assessment indices—the Charlson Comorbidity Index, the Elixhauser Comorbidity Index and CMS’s Hierarchical Condition Category—for predicting mortality and health care utilization among joint replacement patients.

The research team, led by Amit Kumar, a postdoctoral research associate at the Brown University School of Public Health, analyzed Medicare data on every beneficiary who survived for 90 days after a total knee or total hip replacement performed because of osteoarthritis between January 2009 and September 2011. Among the 605,417 patients analyzed, 46.3% were discharged home, 40.9% went to skilled nursing facilities, and 12.7% stayed in inpatient rehabilitation, the release explains.

Kumar’s analysis suggests that the indices made no useful difference at all in predicting where patients would be discharged and whether they’d return to the hospital within 30, 60 or 90 days. In addition, none significantly improved upon a “base model” of merely accounting for a mix of demographic and medical factors.

To rate the base model and the three indices, Kumar relied on the calculation of a number called the “C-Statistic,” which essentially measures the probability that an index would identify as high risk a person who actually turned out to be high risk. By convention, a C-statistic has to be higher than 0.7 to be considered clinically relevant. The base model scored in the 0.63 to 0.65 range, and the indices only nudged those numbers up in the hundredths place, never rising above the 0.7 threshold, the release continues.

When Kumar and his colleagues added functional status data into a predictive risk model—something that the risk models don’t account for because Medicare doesn’t require hospitals to report it—it yielded a substantial improvement.

“The reason we do joint replacements is to reduce pain and improve functional status, but this information is missing from our risk indices,” Kumar says, per the release.

Kumar adds that the CMS should begin tracking the patients’ functional status, with the data tried in a new index that will help hospitals assess which patients are at greatest risk to struggle and will help CMS assess which hospitals are taking on such riskier patients.

[Source(s): Brown University, Science Daily]