Prediagnosis Primary Care Visits Improve Outcomes in Medicare Patients With Colorectal Cancer

Jeanne M. Ferrante, MD

New data show that Medicare beneficiaries with colorectal cancer (CRC) who made a higher number of visits to their primary care physicians (PCPs) before their diagnosis had lower disease-related mortality and lower all-cause mortality than patients who made fewer prediagnosis visits to their PCPs.

“This study adds to the mounting evidence of the benefits of primary care in improving health outcomes and underscores the importance of access to a PCP, particularly for Medicare beneficiaries,” said Jeanne M. Ferrante, MD, with the University of Medicine and Dentistry of New Jersey/Robert Wood Johnson Medical School in Somerset, and associates.

The investigators examined the association between utilization of PCPs and CRC outcomes using a retrospective cohort of individuals diagnosed with CRC within the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked registry between 1994 and 2005. The analysis included 225,459 individuals.

While population-based studies have found that a higher supply of PCPs is associated with a lower incidence of CRC, earlier-stage diagnosis, and lower mortality, it is not possible to determine whether persons with better outcomes received care from PCPs. It is also important to determine the effects of PCPs on CRC outcomes, given the projected shortage of roughly 44,000 adult PCPs by 2025.

Results showed that the likelihood of CRC screening and early-stage diagnosis increased with increasing frequency of PCP visits (P <.001 for trend).

Compared with individuals who had not visited a PCP or had only made 1 such visit, patients who made 5 to 10 visits had increased odds of ever receiving CRC screening at least 3 months before diagnosis (adjusted odds ratio [OR], 2.60; 95% CI, 2.48-2.72) and early-stage diagnosis (adjusted OR, 1.35; CI, 1.29-1.42). Individuals who made 5 to 10 visits had 16% lower CRC mortality (adjusted hazard ratio [AHR], 0.84; 95% CI, 0.80-0.88) and 6% lower all-cause mortality (AHR, 0.94; CI, 0.91-0.97) versus patients with 1 visit or no visits.

Ferrante and colleagues said that the lower CRC mortality seen in Medicare patients with higher PCP utilization seems to be primarily a function of earlier-stage diagnosis and receipt of CRC screening. Given that the association persisted after adjusting for stage and CRC screening, this suggests that PCPs may cut CRC deaths not strictly through CRC screening and earlier diagnosis. For example, PCPs may help promote healthy behaviors and other preventive services, manage comorbid illnesses, and coordinate complex care.

The authors emphasized that “the study only included persons [aged] 67 to 85 years having Medicare fee-for-service insurance who were predominantly white, were relatively healthy, and had a relatively high mean number of physician visits.” Thus, the results are not necessarily relevant for other populations.

Also, the study included only administrative data from the SEER-Medicare database. The database omits factors such as healthy behaviors, severity of comorbid illness, and medication use, all of which may be associated with CRC stage at diagnosis or mortality.

Ferrante JM, McCarthy EP, Gonzalez EC, et al. Primary care utilization and colorectal cancer outcomes among Medicare beneficiaries. Arch Intern Med. 2011;171(19):1747-1757. doi:10.1001/archinternmed.2011.470.