Who should consider colorectal cancer (CRC) screening and why? CRC is a common and costly disease, largely of the elderly, with nearly 25% of cases diagnosed among patients aged 75-84 years, but the guidelines for CRC screening of Americans aged 75 or older vary according to the source. In a study published in the American Journal of Preventive Medicine, researchers found that CRC screening, consistent with recommendations of the U.S. Preventive Services Task Force, is not widely used by this segment of the population even though some patients are healthy and may benefit, and that appropriate follow-up is not taking place in a timely manner for some older adults.

"Completion of CRC screening - including follow-up of abnormal tests - among the elderly is an understudied area that is important for patients, clinicians, policymakers, and researchers to consider so that screening resources are directed to those who may benefit most," explained lead investigator Carrie N. Klabunde, PhD, of the Office of Disease Prevention, National Institutes of Health, Rockville MD.

Investigators analyzed the medical records of close to 850,000 patients enrolled in three integrated health systems, part of the Population-Based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium. They were 65 to 89 years old and were members of Group Health in Washington State and northern Idaho, Kaiser Permanente, Northern California or Kaiser Permanente, Southern California from January 1, 2011, through December 31, 2012.

Two aspects of healthcare were examined in detail: what proportion of patients were up-to-date with CRC screening, and, for those screened with fecal blood tests, what was the likelihood of receiving a follow-up colonoscopy within three months after a positive result? Further, investigators analyzed whether age or the presence of other medical conditions has greater influence on patients' likelihood of undergoing CRC screening or follow-up.

Researchers found that age has a greater influence than comorbidity, the presence of other chronic diseases or conditions, on CRC use in the elderly. "This finding is consistent with practice guidelines that emphasize age cut offs in determining who should be screened. The physicians and health systems represented in this study appear to be adhering to age-focused guidelines. However, the lack of tools to assist clinicians and elderly patients in shared decision making about screening that incorporates the patient's age, health status, preferences, and ability to tolerate screening tests and interventions presents a significant challenge to implementing guidelines that call for more-individualized recommendations," noted Dr. Klabunde.

The study determined that 72% of all individuals aged 65-89 years were up-to-date with screening. Of those up-to-date by fecal blood testing and having a positive result, 65% received follow-up colonoscopy within three months. However, these estimates varied by patient age and comorbidity. Comorbidity was more strongly related to timely follow-up than to screening up-to-date. In all age groups, considerable numbers of patients with no or low comorbidity were not up-to-date with screening or did not receive timely follow-up.

Because all of the participants were insured members of integrated health systems with extensive patient tracking, it is a concern that timely follow-up after a positive fecal blood test decreases with increasing age and comorbidity. Small primary care practices may lack such tracking, leading to even lower follow-up rates.

The authors conclude, "There are many opportunities for improvement in screening completion among the elderly. Primary care practices need to develop and integrate systems to support individualized as opposed to age-based decision making, including risk assessment tools that consider age and comorbidity in estimates of benefits and harms. More research is needed to understand facilitators of and barriers to completing CRC screening, including timely follow-up of abnormal tests, in the elderly."

Article: Influence of Age and Comorbidity on Colorectal Cancer Screening in the Elderly, Carrie N. Klabunde, PhD, Yingye Zheng, PhD, Virginia P. Quinn, PhD, Elisabeth F. Beaber, PhD, Carolyn M. Rutter, PhD, Ethan A. Halm, MD, MPH, Jessica Chubak, PhD, Chyke A. Doubeni, MD, MPH, Jennifer S. Haas, MD, MSc, Aruna Kamineni, PhD, Marilyn M. Schapira, MD, MPH, Pamela M. Vacek, PhD, Michael P. Garcia, MS, Douglas A. Corley, MD, PhD, on behalf of the PROSPR consortium, American Journal of Preventive Medicine, doi: 10.1016/j.amepre.2016.04.018, published online 22 June 2016.