Post-Arthroplasty Outcomes Diverge Based on Insurance

Author: Michael Vlessides

Anesthesiology News

A pair of studies has confirmed the disturbing results of previous research: When it comes to outcomes after surgery—in these cases, either shoulder or total hip arthroplasty—Medicaid and Medicare patients are faring far worse than their counterparts with private insurance.

“Medicaid payor status has previously been identified in the medical literature as a risk factor for increased mortality and morbidity after orthopedic surgery, as well as many other types of surgery,” said Brian Like, MD, MBA, a resident in anesthesiology at NewYork-Presbyterian/Weill Cornell Medical Center, in New York City.

“As such, our hypothesis was that for shoulder arthroplasty, having Medicaid payor status would be associated with increased morbidity, mortality, length of stay (LOS) and readmissions.” This potential relationship can have far-reaching implications, especially in light of the increasing popularity of the procedure, which is performed as many as 85,000 times each year in the United States, and whose prevalence increased 2.5-fold between 1998 and 2008.

Shoulder Arthroplasties

To help answer these questions, the researchers of the first study (abstract 5375) turned to the Healthcare Cost and Utilization Project’s (HCUP’s) State Inpatient Databases (SID) for California, Florida, Kentucky, Maryland and New York. They analyzed the discharge records of 89,460 patients from 2007 through 2014 who underwent inpatient total shoulder, partial shoulder and reverse shoulder arthroplasties. The primary outcomes of the analysis were inpatient mortality, 30-day readmission and 90-day readmission. Secondary outcomes included a variety of cardiac and infectious complications, as well as LOS.

After applying multilevel multivariate logistic regression models that controlled for patient characteristics, the study found that Medicaid patients undergoing shoulder arthroplasties had four times greater odds of inpatient mortality (odds ratio [OR], 4.09; 95% CI, 1.73-9.70; P<0.01), increased 30-day readmission (OR, 2.20; 95% CI, 1.76-2.75; P<0.001), and 90-day readmission (OR, 1.80; 95% CI, 1.53-2.13; P<0.001) compared with private insurance.

The study also revealed that Medicaid-insured patients were at an increased likelihood of developing infectious complications (OR, 2.31; 95% CI, 1.59-3.35; P<0.001) and longer hospital LOS (incidence rate ratio, 1.34; 95% CI, 1.30-1.39; P<0.001). Being insured by Medicaid did not, however, affect the likelihood of developing cardiovascular complications (OR, 0.87; 95% CI, 0.51-1.50).

“These results confirmed our hypothesis that Medicaid payor status would lead to worse outcomes,” Dr. Like said. “This is consistent with previous literature.”

Another study presented (abstract 5546) by Harmandeep Singh, MD, a chief resident in anesthesiology at NewYork-Presbyterian/Weill Cornell, illustrated similar disparities between patients on Medicare and those with private insurance. For this analysis, the researchers again used the HCUP’s SID to identify the hospitalization and discharge records of 274,851 adults who underwent a total hip arthroplasty between 2007 and 2011 in California, Florida and New York.

The analysis revealed that readmission rates of all types were greater in Medicare patients. Indeed, the most common reasons for 30-day readmissions included wound infection (15.7% private insurance vs. 19.3% uninsured), atrial fibrillation (5.9% private insurance vs. 18.4% Medicare), urinary tract infection (6.3% private insurance vs. 13.3% Medicare), and pneumonia (3.4% private insurance vs. 6.9% Medicare).

Similarly, the most common reasons for 90-day readmissions included atrial fibrillation (5.5% private vs. 16.9% Medicare), urinary tract infection (4.5% private vs. 12.0% Medicare), wound infection (9.3% private vs. 12.1% uninsured), and pneumonia (2.7% private vs. 6.2% Medicare).

“We don’t have any answers yet in terms of what can be done to close this gap,” he added. “If there was anything that stood out, people would have already acted on it. But I think we’ve highlighted this variability in an attempt to dig deeper into these disparities and begin more studies to figure out ways to close this gap.”

Session moderator Andrea Nicol, MD, an assistant professor of anesthesiology at the University of Kansas Medical Center, in Kansas City, was moved by the findings. “These results are striking, and the difference in mortality, especially, tugs at my heartstrings,” she said. “It’s really sad.”