Use of colorectal cancer screenings in the U.S. increased, but still underused

Interventions that are aimed at reducing barriers could be effective in saving lives, NIH claims.

Issue: May 25, 2010

Although screening rates for colorectal cancer have increased, the disease remains the third-leading cancer diagnosis in the United States and the second-leading cause of cancer-related deaths.

In adults aged 50 years and older, overall screening rates rose from 20% to 30% in 1997 to nearly 55% in 2008. However, those numbers represent results from self-reported surveys and may overestimate the actual number of patients screened.

In a state-of-the-science conference statement prepared by a panel of experts, the NIH said screening is underused and that targeted initiatives to improve rates and reduce disparities “could further reduce colorectal cancer morbidity and mortality.” The statement was published in Annals of Internal Medicine.

“This could be achieved by using the full range of screening options and evidence-based interventions for increasing screening rates,” panel members wrote. “With additional investments in quality monitoring, U.S. citizens could be assured that all screening achieves high rates of cancer prevention and early detection.”

Proposed initiatives

The panel proposed six initiatives to achieve the overall goal of increasing screening for colorectal cancer:

Eliminate financial barriers to colorectal cancer screening and appropriate follow-up.
Widely implement interventions that have proved effective at increasing colorectal cancer screening, including patient reminder systems and one-on-one interactions with providers, educators or navigators.
Implement systems to ensure appropriate follow-up of positive results of colorectal cancer screening.
Develop systems to ensure high quality of colorectal cancer screening programs.
Conduct research to assess the effectiveness of tailoring programs to match the characteristics and preferences of target population groups to increase colorectal cancer screening.
Conduct studies to determine the comparative effectiveness of the various colorectal cancer screening methods in usual practice settings.

Donald Steinwachs, PhD, director, Health Services Research and Development Center at Johns Hopkins Bloomberg School of Public Health, and the other panel members wrote that medical insurance and access to a usual source of health care are the two most important factors influencing a patient’s decision to undergo screening. Additionally, higher income and education level are closely correlated with an increase in screening.

Effective patient-level interventions, they said, reduce structural barriers for patients. Direct mailing of fecal occult blood test kits, for instance, have been shown to improve rates of screening, as have one-on-one interaction with a health care provider or health educator, and patient reminders.

However, there have been few studies into the efficacy of provider or health care system-level interventions. Panel members said they want to see more research to determine what interventions, if any, encourage more patients to get screened.

“The scientific evidence is mixed on the effectiveness of community-based interventions for increasing rates of colorectal cancer screening,” they wrote. “There is also a need to understand whether health education, decision-making tools that incorporate patient preferences, patient or physician financial incentives, or mass-media messaging strategies can effectively motivate patients across diverse populations to participate in screening efforts.”

Negative consequences

There could be negative consequences to a dramatic increase in the rate of screening. As panel members said, the few studies exploring whether the health care system has the capacity to handle such an increase are nearly a decade old and focus only on endoscopic capacity.

“These data are limited by the uncertain validity of current endoscopic volume and available capacity estimates, lack of standard definitions, and lack of distinction between screening and surveillance colonoscopy,” panel members wrote. “Of note, the results of these studies vary widely, probably reflecting differences in assumptions about uptake, the size of the eligible population, and the available workforce and facilities. In addition, they do not account for the resources needed to reach the many persons who are unscreened.”

Additionally, although colorectal cancer screening is generally underused, testing is also frequently overused. A review of the NIH statement also published in Annals of Internal Medicine found that, in patients aged 85 and older with severe comorbid conditions, too frequent use of postpolypectomy surveillance colonoscopy and polypectomy for polyps 5 mm or smaller are common examples of overuse.

“We also found underuse and low-quality of discussions between patients and health professionals about [colorectal cancer] screening, even though national guideline groups recommend such discussions,” Holden and colleagues wrote.

They found that many interventions, such as providing one-on-one counseling by non-physician staff to help patients understand screening and reminding patients when they need screening, improved the rate of appropriate screening for some patient populations. However, the capacity to deliver those interventions “is hindered most fundamentally by policies that determine how health care is structured and paid for.”

“It remains unclear whether any specific intervention or program of combined interventions would effectively increase screening rates across the country,” they wrote. “Given the variation of practice models, practice sizes, degree of system integration and availability of tests, our ability to implement organized screening programs and interventions on a broad scale within and across medical practices is uncertain at best.”

For more information:

Holden DJ. Ann Intern Med. 2010; doi:10.1059/0003-4819-152-10-201005180-00239.

Steinwachs D. Ann Intern Med. 2010; doi:10.1059/0003-4819-152-10-201005180-00237.