Lack of follow-up after fecal occult blood testing in older adults: inappropriate screening or failure to follow up?

Abstract

Background: It is unclear whether lack of follow-up after screening fecal occult blood testing (FOBT) in older adults is due to screening patients whose comorbidity or preferences do not permit follow-up vs failure to complete follow-up in healthy patients.

Methods: A prospective cohort study of 2410 patients 70 years or older screened with FOBT was conducted at 4 Veteran Affairs (VA) medical centers from January 1 to December 31, 2001. The main outcome measure was receipt of follow-up within 1 year of FOBT based on national VA and Medicare data. For patients with positive FOBT results, age and Charlson comorbidity scores were evaluated as potential predictors of receiving a complete colon evaluation (colonoscopy or sigmoidoscopy plus barium enema), and medical records were reviewed to determine reasons for lack of follow-up.

Results: A total of 212 patients (9%) had positive FOBT results; 42% received a complete colon evaluation within 1 year. Age and comorbidity were not associated with receipt of a complete follow-up, which was similar among patients 70 to 74 years old with a Charlson score of 0 compared with patients 80 years or older with a Charlson score of 1 or higher (48% vs 41%; P=.28). The VA site, number of positive FOBT cards, and number of VA outpatient visits were predictors. Of 122 patients who did not receive a complete follow-up within 1 year, 38% had documentation that comorbidity or preferences did not permit follow-up, and over the next 5 years 76% never received a complete follow-up.

Conclusions: While follow-up after positive FOBT results was low regardless of age or comorbidity, screening patients in whom complete evaluation would not be pursued substantially contributes to lack of follow-up. Efforts to improve follow-up should address the full chain of decision making, including decisions to screen and decisions to follow up.

Figure 1

Study Flow Diagram *Only patients who had Fecal Occult Blood Testing (FOBT) as their first colorectal cancer screening test in 2001 were included (i.e., Patients whose first test in 2001 was colonoscopy, sigmoidoscopy, or barium enema were excluded). ^† Defined by searching VA and Medicare inpatient and outpatient claims, dating as far back as October 1, 1992 for VA claims and January 1, 1999 for Medicare claims. While some FOBT performed after a recent colonoscopy or barium enema and flexible sigmoidoscopy may be for screening purposes, these patients generally do not require repeat complete colon evaluation regardless of the FOBT result, so they were excluded in order to focus on the impact of age, comorbidity, and preferences on follow-up after an abnormal screening FOBT result. ^‡ Symptoms were defined by VA and Medicare inpatient and outpatient claims as well as review of VA electronic medical records.

Figure 2

Follow-up testing performed within 1 year after screening fecal occult blood testing (FOBT) among persons 70 years or older, according to FOBT result.* *Follow-up tests were identified using national VA and Medicare data.

Figure 3

Cumulative incidence of complete colon evaluation (colonoscopy or barium enema plus sigmoidoscopy) after a positive fecal occult blood test result, according to age and comorbidity.