(Reuters Health) - Black people with knee osteoarthritis may have a worse quality of life than white patients in part because they’re less likely to be offered knee replacement surgery or to get the procedure when it’s recommended, a U.S. study suggests.

Knee replacement surgery has the potential to turn back the clock for people suffering from severe joint pain that limits their mobility and makes it hard for them to complete daily tasks. While surgery can’t return people to the same level of comfort and function they had before they developed arthritis, it can make them feel much less disabled.

Based on the current rates of knee replacement surgery among all black and white men and women in the U.S. who might qualify for the procedure, researchers estimated that blacks are potentially missing out on tens of thousands of years with better quality of life compared to their white counterparts, according to the report in Arthritis Care & Research.

The researchers created a computer model to estimate the effect of knee replacement on what’s known as quality-adjusted life years (QALY), which is a measure of both functional ability and its impact on overall quality of life, and takes into account total expected duration of life.

“Underutilization of the highly successful surgery leads to drastic losses of quality adjusted life years among racial minorities,” said senior study author Elena Losina, an orthopedics researcher at Brigham and Women’s Hospital and Harvard Medical School in Boston.

In the computer simulation developed by the researchers, hypothetical patients were 66 years old, on average, and usually had moderate to severe knee osteoarthritis. This is a typical age and symptom burden experienced by people who get surgery in the U.S.

Then, the study team estimated that about 23 percent of white patients and 12 percent of black patients would be offered total knee replacement surgery, based on findings from previous research done in the Veterans Affairs healthcare system.

Based on results from a different study, researchers then estimated that 83 percent of white men and 59 percent of black men offered surgery decided to get the operation, as did 78 percent of white women and 64 percent of black women.

They also calculated probabilities of complications like heart attacks, pneumonia, a blockage in the pulmonary artery or death in the first year after surgery.

After plugging in all these numbers, researchers calculated that based on current rates of knee replacement, there is a QALY gain of 4.8 per 100 black men, 8.2 per 100 black women, 12.6 per 100 white men and 15.7 per 100 white women.

Put another way, black men and women gain QALY as a result of knee replacements, but they could be gaining many more high-quality years if they were offered and accepted surgery at the same rates as white patients and had similar complication rates, the authors conclude.

The study isn’t a controlled experiment designed to prove whether or how differences in surgery options or outcomes between black and white people might translate into differences in quality of life or disease burden. Estimates from a computer model also may not reflect what would happen in a real population of patients.

Nor does it address why there are racial disparities in the proportion of patients who are offered, or who accept knee replacement in the first place.

The study doesn’t account for patient preferences, and some previous research suggests that black people may be less willing to undergo knee replacement procedures, said Dr. Said Ibrahim, a researcher at Weill Cornell Medicine in New York City who wasn’t involved in the study.

“Access to insurance or lower prevalence of knee osteoarthritis among minority patients is the not the reason,” Ibrahim said by email. “Similarly, it is not clear that orthopedic surgeons, who are predominantly white men, are less willing to operate on minority patients with health insurance.”

Instead, patient preference may play a role, Ibrahim said. Minority patients may have concerns about complications and they may be more likely to receive treatment at low-quality hospitals where surgeons don’t do as many knee replacements and get worse outcomes, he added.

“This new study is very important in that it shows for the first time that lower utilization of this effective treatment is associated with quality of life price,” Ibrahim said. “This matters to patients, because the two most important indications for this treatment are pain control and quality of life improvement.”

SOURCE: bit.ly/2ENZjmJ Arthritis Care & Research, online January 24, 2018.