In 2012, the United States Preventive Services Task Force convened to determine whether it should recommend kidney disease screening for all Americans. Advocates had been pushing for it, citing ballooning rates of chronic kidney disease. But at the time, the group found there wasn’t enough evidence to say if screening was a net good.
That paradigm has since shifted, says Marika Cusick, a Ph.D. candidate in health policy at Stanford. The entry of new drugs, sodium-glucose cotransporter-2 (SGLT2) inhibitors that have shown efficacy in clinical trials, has made national kidney disease screening cost-effective, she says. Her findings were reported in a study published Monday in the Annals of Internal Medicine.
“Before, we didn’t have a good treatment option, an effective treatment option for CKD. And so that’s why early detection didn’t necessarily improve outcomes,” Cusick told STAT. “And now, because we have an effective treatment option, I think that the value of screening is really different.”
While SGLT2 inhibitors were initially used to treat people with type 2 diabetes, in trials they were found to also slow the degradation of kidney function in those without diabetes. Empagliflozin, marketed as Jardiance, is among the more popular of this class of drugs, which also includes canagliflozin and dapagliflozin. The introduction of SGLT2 inhibitors is a “breakthrough in nephrology,” said Gregorio Obrador, a nephrologist and professor at the Universidad Panamericana who has studied early detection of CKD in Mexico.
Cusick first studied the bang-per-buck when dapagliflozin, a drug often used to control high blood sugar, was added to the standard of care for people with nondiabetic chronic kidney disease. It was cost-effective, she found.
Then she wanted to know: Would it be cost-effective to do population-wide chronic kidney disease screening — using a urine test that detects albumin — plus treatment with an SGLT2 inhibitor? Cusick and her colleagues, including Stanford nephrologist Glenn Chertow, found it would make a big difference. (Chertow was lead author on a paper about dapagliflozin out of the large “DAPA CKD” trial, which was funded by AstraZeneca. He has also received research grants from Amgen and speaking, advising, and other fees from almost two dozen biopharma companies. Cusack has no conflicts of interest related to the issue.)
Using existing data and a model to extrapolate results to the full U.S. population, they found one-time screening and use of SGLT2 inhibitors could keep nearly 400,000 people from going on dialysis or needing a kidney transplant in their lifetime.
Screening every five years, plus SGLT2 inhibitors, could prevent about 658,000 people from needing dialysis or transplant compared with the status quo. For those 35 to 45 years old, Cusick found screening every decade gives “good value,” while more frequent screening for adults ages 55 to 65 would be appropriate, considering the increase in CKD prevalence in that age group.
“It provides good value in terms of the way we spend our health care dollars,” she said. “It does increase costs, in terms of adding costs for screening and future treatments. However, the downstream health benefits that come from that are well worth it, according to our analysis.”
Cusick and her team used a standard model for calculating cost-effectiveness, and looked at quality-adjusted life years, an economic measure that balances how much time and what quality of time a person might gain from a medical intervention.
Obrador called Cusick’s work “quite interesting,” and considered its global implications.
“In high-income countries, screening the general population for CKD may be cost-effective as far as SGLT2s are available,” he said. “The cost may be very high in low- and middle-income countries, so limiting CKD screening to high-risk populations would be more reasonable.”
The U.S.-based results make sense when one considers the huge financial burden of end-stage kidney disease in the U.S., Cusick noted. Every year, Medicare spends $87 billion on chronic kidney disease, and another $37 billion on care for people with kidney failure, those living on dialysis or in need of a kidney transplant. Later-stage care is very expensive to the health care system. And when an estimated 90% of people with chronic kidney disease don’t know they have it because the disease is asymptomatic until later stages, early detection and treatment could avoid major costs down the road — and potentially save lives.
Paul Komenda, chief medical officer of Quanta Dialysis Technologies and a professor of medicine at the University of Manitoba, said SGLT-2 inhibitors’ efficacy “renders legacy CKD screening guidelines obsolete.”
Spending on universal CKD screening “represents excellent value for money,” he said. “More importantly delaying or preventing the need for dialysis with the broad application of this game-changing group of medications is a critically important step in improving patient lives.” Costs could be further shaved by using innovative and cheap methods of screening, Komenda said.
Late-stage kidney disease and kidney failure also disproportionately affect people of color. About 35% of people on dialysis in the U.S. are Black. Native Americans, Asian people, and Hispanic people are also at higher risk of kidney failure than non-Hispanic white people, according to data from the National Institutes of Health.
LaVarne Burton, president and CEO of the American Kidney Fund, cited these stark statistics in a letter to the USPSTF last year, urging it to develop a CKD screening recommendation for patients at higher risk of kidney disease. “Kidney failure radically changes a person’s life and lifestyle, including an inability to work for most patients because of the need for ongoing dialysis,” the letter said. “Allowing patients to find out early that they have kidney disease provides the opportunity for lifestyle changes and the opportunity to slow or halt the progression of the disease and possibly prevent renal failure.”
Other countries, such as Mexico, have screening programs for people considered high-risk for chronic kidney disease — those with diabetes, high blood pressure, or a family history of CKD. In January, the USPSTF took up kidney disease screening again. In a process that could take multiple years, the group will analyze available evidence, hear from the public, and decide whether population-level CKD screening is likely to be beneficial. As with all screening, there is the potential for harm: people undergoing unnecessary, expensive or risky diagnostic tests, procedures and therapies, false positives, and more.
Cusick said she hopes the group will take her work into consideration when deliberating. Her findings suggest national screening and use of SGLT2 inhibitors could create more benefits than harms. One key caveat is that cost-effectiveness relies on SGLT2 inhibitors being affordable and proving effective in slowing CKD progression and reducing all-cause mortality. While short-term trials have shown promise for this class of drugs in fighting the progression of kidney disease, there needs to be more long-term evidence of how these drugs work in the real world. The researchers were also limited by the amount of data they had to work with, so cost-effectiveness should become clearer as more information becomes available.
STAT’s coverage of chronic health issues is supported by a grant from Bloomberg Philanthropies. Our financial supporters are not involved in any decisions about our journalism.
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