The study included 1,108,424 North Carolina and South Carolina Medicare enrollees aged 65 to 85 (). Of these, 46.5% were not compliant and not tested in 2005; 21.9% had a CRC test in 2005; and 31.6% were compliant with CRC tests and were excluded from further analyses. Of those who needed a CRC test in 2005 (n = 757,594), 68% did not receive one. Compared with enrollees who had any CRC test in 2005, those who did not receive a test were more likely to be of minority race or Hispanic ethnicity (20.4% vs 14.4%); to have originally entered Medicare because of a disabling condition (11.1% vs 8.8%); and to be eligible for a state buy-in program (18.3% vs 10.3%). Those with no test in 2005 were more likely to be classified as unknown in terms of comorbid conditions (15.6% vs 4.4%), likely because of a limited number of health claims in 2004.
Characteristics of Fee-For-Service Medicare Enrollees, by Colorectal Cancer Test Status, North Carolina and South Carolina, 2005
Lack of a physician visit during the previous year was higher among enrollees with no CRC tests compared with enrollees who had a CRC test in 2005 (19.8% vs 5.4%) (). Those not tested in 2005 had, on average, fewer physician visits than those who were tested (4.7 visits vs 7 visits). Among enrollees who were not tested in 2005, 45% received care exclusively from primary care physicians (). Enrollees without a test in 2005 were less likely than enrollees with a test to have received care from both primary care and nonprimary care physicians (17% vs 24%) and from physicians with primary care, nonprimary care, and mixed specialties (10% vs 18%).
Physician Office Visits by Fee-for-Service Medicare Enrollees, by Colorectal Cancer Test Status, North Carolina and South Carolina, 2005
Type of Physicians Seen by Fee-for-Service Medicare Enrollees With Any Visit, North Carolina and South Carolina, 2005
Of all Medicare patients who received care from at least 3 different types of physicians (primary care, nonprimary care, and mixed-specialty physicians), only half had a CRC test in 2005 (). Less than one-third of patients who had only primary care, nonprimary care, or mixed-specialty visits had a CRC test.
Percentage of fee-for-service Medicare enrollees current with colorectal cancer (CRC) testing, by physician type, seen by any physician, North Carolina and South Carolina, 2005.
|Type of Physician Seena||Medicare Patients With Colorectal Cancer Test, %
|Primary care, nonprimary care, and mixed specialty visits||50.6|
|Primary care and nonprimary care visits||43.9|
|Mixed specialty and nonprimary care visits||38.5|
|Primary care and mixed specialty visits||37.5|
|Primary care visits only||28.7|
|Mixed-specialty visits only||25.0|
|Nonprimary care visits only||23.9|
Medicare patients with obstetrician/gynecologist visits were most likely to be tested in 2005 (47%), followed by patients who had seen physicians with multiple specialties (). Patients who had visits with family or general practice physicians were least likely to be tested (29%). No primary care specialty was without missed opportunities: less than half of the patients with primary care visits in 2005 had a CRC test, regardless of the primary care specialty of the physicians.
Percentage of fee-for-service North Carolina and South Carolina Medicare enrollees who were seen by primary care physicians in 2005, current with CRC testing, by primary care specialty
|Type of Primary Physician Seen||Medicare Patients With Colorectal
Cancer Test, %
|Obstetrics and gynecology||46.6|
|Other (multiple specialties seen)||43.5|
|Internal medicine, preventive medicine, geriatrics||40.0|
|Physician assistant or nurse practitioner||29.9|
|Family and general practice||29.1|
Model 1 () revealed a strong, positive association between the number of visits and having a test, with a monotonic increase in the likelihood of having a CRC test as the number of visits increased. Enrollees with 1 to 5 visits were more than twice as likely to have had a test as those with no visits (OR, 2.6; 95% CI, 2.6-2.7). Enrollees with 21 or more visits were 8 times as likely to have had a test as those with no visits (OR, 8.3; 95% CI, 7.9-8.6).
Influence of Number and Type of Physician Office Visits on Receipt of Colorectal Cancer Testing by Fee for Service Medicare Enrollees, North Carolina and South Carolina, 2005
Model 2 () showed that enrollees whose visits included contact with a primary care physician were significantly more likely to be tested in 2005 than enrollees with nonprimary care visits. Odds ratios for all categories of physician visits that included primary care visits were significantly greater than 1. Although the number of visits remained an important predictor, the effect was attenuated by type of physician included in the model.
In Model 3 (), enrollees who saw family or general medicine physicians were less likely to have had a CRC test (OR, 0.61; 95% CI, 0.60-0.62) than those who visited physicians with internal medicine, preventive medicine, or geriatric specialties. Enrollees who saw obstetrician/gynecologists were more likely to have had a CRC test (OR, 1.23; 95% CI, 1.17-1.29).
In all 3 models, demographic characteristics were significantly associated with receipt of CRC test. Medicare enrollees who were older, minority race or Hispanic ethnicity, or male were less likely to be tested. Enrollees originally eligible because of disability and those entitled to state buy-in (a marker for low income) were also less likely to have had a CRC test. Enrollees with evidence of any comorbid conditions were less likely to have had a CRC test. State variation was also observed: enrollees from South Carolina were more likely to have had CRC tests than those from North Carolina.