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.




April 7th, 2015


April 28th, 2015