Screening CT colonography (CTC) is almost a third less expensive than colonoscopy in Medicare patients, according to a new report in Abdominal Imaging. The results are promising for what advocates hope is imminent approval of Medicare payment for the CT-based test, which has suffered daunting delays on the path to reimbursement for well over a decade.
The study authors used Medicare claims data, fee schedules, and established protocols to estimate the costs per screening exam for both CTC and optical colonoscopy (OC). In an asymptomatic population, CTC was 29% less costly than colonoscopy, even when CTC required follow-up colonoscopy, reported Bruce Pyenson and colleagues from actuarial firm Milliman in New York City, along with Dr. Perry Pickhardt from the University of Wisconsin in Madison.
"For our base scenario, CTC is 29% less costly than OC per Medicare enrollee," the group wrote. "Although the CTC cost advantage is quite variable under the alternative scenarios, the cost advantage is positive for all alternative scenarios" (Abdom Imaging, September 9, 2015).
Is an update in order?
The last cost analysis for CTC versus colonoscopy occurred in 2009 -- the same year that CTC was denied for Medicare reimbursement. But the study authors believe an update is in order, owing to the many changes that have occurred since then in reimbursement and clinical practice, as well as what the researchers saw as shortcomings in methodology.
"I think what's unique about this study is that we very carefully looked at what Medicare pays," said Pyenson in an interview with AuntMinnie.com. "I think that often studies are done without carefully thinking though and following everything that Medicare pays for."
The current study aimed to compare the costs of initial CTC versus initial colonoscopy, addressing the third of three aims adopted by the U.S. Centers for Medicare and Medicaid Services (CMS) for tests:
- Improve the patient experience of care
- Improve the health of populations
- Reduce the per-capita cost of healthcare
Cost aside, CTC offers several distinct advantages over OC including its noninvasiveness, improved safety profile, and ability to detect potentially serious extracolonic findings, the authors noted. The main drawback is that colonoscopy must eventually be called into service if CTC finds clinically significant polyps.
Approval for CTC for colorectal screening currently rests in the hands of the U.S. Preventive Services Task Force (USPSTF), which is reviewing the evidence this year in light of new studies that aim to fill perceived gaps, especially in the Medicare population. If CTC receives an "A" or "B" rating, and CMS concurs with that judgment, then insurers will be required to pay for CTC as a covered colorectal cancer screening test.
Building a model
The study team modeled estimated CTC and optical colonoscopy costs, the frequency of colonic and extracolonic findings, and the screening times, size, and demographic mix of the populations.
In an improvement over some previous studies, calculated costs always referred to Medicare allowed payments, including the Medicare payment and the Medicare cost-sharing payment. With regard to bowel preparation agents, allowed amounts ($39) are paid by the Medicare Part D insurer. With CTC, for example, some bowel preparation agent costs are included with the total CTC costs, while for optical colonoscopy these costs are billed separately, Pyenson explained.
The model assumes perfect adherence to a CTC or colonoscopy screening path, with no going back and forth between the two. Rescreening with colonoscopy was set at 10 years, while rescreening with CTC was set at five years, per current guidelines.
For the model, the investigators identified 127,175 Medicare colonoscopies performed in 2013; they classified 56,578 (44%) as screening colonoscopies for calculating average costs. Many of the remaining procedures were considered diagnostic or were performed on enrollees younger than 50.
They estimated the 2015 average Medicare colonoscopy screening cost, including technical and professional components, to be $1,035, ($1,212 with and $824 without biopsies). The estimated cost of CTC was $243, including $123 in professional costs and $120 in technical costs.
In the base scenario, which assumed a colonoscopy follow-up rate of 12.9%, the average cost savings of the CTC approach was 29% per Medicare enrollee, compared with colonoscopy. In the alternative scenarios, the cost advantage was variable but still positive, ranging from 12% to 58%, according to the authors.
| Cost of CTC vs. colonoscopy by screening scenario | |
| Screening scenarios | CTC savings vs. colonoscopy |
| Base scenario | 29% |
| Fewer large and small polyps | 35% |
| Add costs for OC and CTC complications and CTC extracolonic findings | 12% |
| Decrease maximum screening age | 33% |
| Decrease OC follow-up rate for CTCs with small polyp findings | 34% |
| Increase OC follow-up rate for CTCs with small polyp findings | 25% |
| Decrease rescreen years for both OC and CTC for screenings with small polyps | 30% |
| Increase CTC rescreen years to match OC | 58% |
Drilling further into the data, Pyenson observed that extracolonic findings at CTC do not seriously raise costs, but bowel perforations at optical colonoscopy are very expensive. In other words, while extracolonic findings affect CTC costs, CTC is safer -- complications add more costs to optical colonoscopy than CTC.
Another big item in the price tag is how often anesthesia is used in conventional colonoscopy, because its costs are significant, Pyenson said. Deep sedation (often propofol) is administered by an anesthesiology professional and billed to Medicare at an average cost of $154.
Separate modeling is needed for private insurers, who generally pay much higher fees for anesthesia and colonoscopy than Medicare does, the authors wrote. Also, future fee schedules, even for Medicare, are likely to change significantly -- and with them the relative cost advantages of CTC.
"For a Medicare population, when compared to OC, CTC satisfies the third goal of the triple aim: reducing the per-capita cost of healthcare," the authors concluded.
Are these results expected to inform USPSTF's decision-making process with regard to the comparative costs?
"I don't know impact because USPSTF is supposed to not consider costs," Pyenson said. "However, I think some of the statistics we have in here on just what happens -- the biopsies, the anesthesia, etc. -- they may take note of. And I believe the [Medicare Evidence Development and Coverage Advisory Committee (MEDCAC)] process will take note of the costs for Medicare coverage."
"The takeaway is that CTC is a high-value alternative to optical colonoscopy screening," he concluded. "It's reasonable for it to be the first option."
