NEW YORK (Reuters Health) - Follow-up colonoscopy is both overused and underused, two new studies indicate.
Too often, patients at high-risk for colorectal cancer don’t receive timely “surveillance” colonoscopy but there is also over-utilization among low-risk patients who are unlikely to develop colon cancer, researchers found.
“This misuse wastes health care resources and risks development of cancers in high-risk patients that might have been preventable,” Dr. Robert Schoen, of the University of Pittsburgh School of Medicine, and senior investigator on both studies, said in a written statement.
“We want people to get screened” for colorectal cancer with colonoscopy, Schoen told Reuters Health. “The issue is in the repeated colonoscopies,” he said.
Colonoscopy involves inserting a thin, flexible scope into the colon to look for cancer or polyps, which are growths that can become cancerous. With colonoscopy, the entire length of the colon can be inspected and any growths discovered can be immediately removed. It is considered the most sensitive way to screen for colon cancer.
Schoen and colleagues analyzed data on 3,627 participants in a large National Cancer Institute-sponsored cancer screening trial and found “substantial overuse” of surveillance colonoscopy among people at low-risk for colorectal cancer and “significant underuse” among those at high-risk.
Specifically, among 1,029 patients with no precancerous colorectal growths at their initial exam, 58 percent underwent a follow-up exam an average of every 3.9 years, although the recommendation would be to do so every 5 to 10 years. The researchers were unable to identify medical reasons for the premature follow up exams.
The researchers also found that within 5 years of the initial colonoscopy exam, only 58.4 percent of patients with advanced precancerous growths had a follow-up colonoscopy, despite the recommendation that they do so every 3 years.
“This is a clear example of an intervention not being utilized in relation to the risk,” said Schoen, whose study appears in the latest issue of the journal Gastroenterology.
The other study, published in the journal GIE: Gastrointestinal Endoscopy, shows that colorectal cancer may still occur, despite regular colonoscopy. In this study, Schoen and associates examined the timing and effectiveness of follow-up colonoscopy in 1,297 patients with a history of precancerous colorectal growths who had follow-up colonoscopy as recommended and were followed for up to 10 years.
Despite following the recommended surveillance schedule, nine people were diagnosed with colorectal cancer during the follow-up period.
The test is “not perfect -- it’s never going to be perfect,” Schoen told Reuters Health.
“This study,” he added in a statement, “emphasizes that patients with a history of advanced polyps are at particular risk and should be monitored closely with timely surveillance examinations.”
In a written commentary, Dr. John Allen of the University of Minnesota School of Medicine in Minneapolis notes that both the overuse and underuse of surveillance colonoscopy is further evidence of a broken healthcare system in the United States.
He points to many contributing factors: The science identifying who should get special surveillance is unclear; the payment system encourages overuse; and patients at high risk get lost in a poorly coordinated medical record keeping system.
Allen urges a dramatic change in the way medicine is practiced and paid for. A “game changer,” as he put it, would throw out fee-for-service payments for each procedure, which encourages overuse, and replace it with payments based on quality care and outcomes.
In an interview with Reuters Health, Allen said there are examples of regional organizations that have successfully implemented quality care systems such as Intermountain Healthcare, Geisinger Health Systems, Mayo Clinic and Kaiser Permanente.
Allen also urges more accountability through the development of publicly available community based registries that look beyond procedures to factor in resource use, complications and patient outcomes.
SOURCES: Gastroenterology, January 2010; Gastrointestinal Endoscopy, January 2010