More primary care visits may lower colorectal cancer incidence, mortality

Medicare beneficiaries who see their primary care clinicians more often have lower colorectal cancer incidence and mortality rates and lower overall mortality, a study found.

Researchers conducted a population-based, case-control study among Medicare patients ages 67 to 85 years diagnosed with colorectal cancer between 1994 and 2005 in U.S. Surveillance, Epidemiology, and End Results (SEER) regions. Primary care was defined as general practice, family medicine, primary care internal medicine, geriatric medicine, and obstetrics-gynecology.

Results appeared in the Oct. 1 Annals of Internal Medicine.

Compared with people who had 0 or 1 primary care visit, those with 5 to 10 visits had less colorectal cancer (adjusted odds ratio [OR], 0.94; 95% CI, 0.91 to 0.96). A stratified analysis found that the association between primary care visits and lower colorectal cancer incidence occurred in patients with late-stage diagnosis and distal lesions, as well as in those diagnosed during years with greater Medicare coverage of colorectal cancer screening tests. There was a higher likelihood of diagnosis of early-stage cancer and proximal cancer with increased primary care visits.

Compared with people who had 0 or 1 primary care visit, those with 5 to 10 visits had less mortality (adjusted OR, 0.78; 95% CI, 0.75 to 0.82) and lower all-cause mortality (adjusted OR, 0.79; 95% CI, 0.76 to 0.82). A stratified analysis found that associations of primary care visits with fewer colorectal cancer deaths were stronger for patients with late- versus early-stage diagnosis, those with distal versus proximal lesions, and those diagnosed during years with greater Medicare coverage of screening tests.

Analyses that controlled for all covariates except colorectal cancer screening and polypectomy showed that having at least 2 primary care visits was associated with approximately 20% lower odds of all-cause mortality compared with 0 or 1 visit (adjusted OR, 0.79 to 0.82). This association was attenuated but not eliminated when colorectal cancer screening and polypectomy were added (adjusted OR, 0.88 to 0.92).

The researchers wrote, “In particular, primary care helps decrease CRC [colorectal cancer] by promoting screening and facilitating referrals for colonoscopy and polypectomy. Because a recommendation from primary care is one of the strongest predictors of adherence to CRC screening and several different options are available for CRC screening, access to primary care is important for counseling on these options. The move toward patient-centered medical homes will probably improve rates of CRC screening because of the model's emphasis on preventive care and tracking of tests in its patient population.”