Article Title

Adverse Effects of Fecal-Based Colorectal Cancer Screening

Publication Date



fecal-based colorectal cancer screening, harms of cancer screening


Background/Aims: Individuals report that the colorectal cancer (CRC) screening process is stressful and, for some, studies indicate that this stress has a downstream impact on motivation to engage in health behaviors and use of health care services. We examined ambulatory primary care (APC) utilization following a false-positive fecal immunochemical test (FIT) to screen for CRC among patients enrolled at the Kaiser Permanente Northern California PROSPR site between 2007 and 2011.

Methods: Included were adults aged 50–89 years who were enrolled in Kaiser Permanente Northern California continuously for 36 months. The first FIT completed during this period for those with a true-negative FIT (negative FIT and not diagnosed with CRC in the subsequent 12 months) and a false-positive FIT (no CRC or adenoma detected with diagnostic colonoscopy following a positive FIT) was identified. The mean number of APC visits in the 12 months following the FIT screening result was compared to the prior 12-month period. Associations between differences in APC utilization pre- to post-FIT by test result and patient demographic characteristics and Charlson comorbidity score were assessed.

Results: We examined 582,997 electronic medical records. For true-negative FIT, we did not detect a change in the number of APC visits pre- vs. post-FIT, whereas there was an increase among patients with a false-positive FIT. Comparison of mean APC visits pre- to post-FIT screening for true-negative FIT was -0.02 (standard deviation [SD]: 2.4] vs. 0.57 [SD: 2.6] for false-positive FIT (P<0.001). In multivariable analysis, those with a false-positive FIT were 64% more likely to have increased APC utilization post-FIT compared to those with a true-negative FIT and that utilization tended to increase with age. Those with no comorbidities were 45% more likely to increase their APC utilization post-false-positive FIT, and this association decreased as comorbidities increased. Men were less likely than females to engage in increased APC utilization post-false-positive FIT.

Discussion: This study demonstrates that primary care utilization varies significantly by fecal-based colorectal cancer screening test result. Further evaluation of the nature of these visits, as well as underlying behavioral determinants of the utilization is warranted.