Our blinded, randomized, controlled study showed that a simple, low cost mailed educational reminder resulted in an absolute 16.2 percentage point higher FOBT card return rate compared with usual care (64.4% vs. 48.4%) in patients that had received face-to-face discussions with their PCP concerning CRC screening and who agreed to this type of screening.
Our study was not designed to determine overall compliance with FOBT testing, but some estimates of this can be made. During the study period, FOBT testing was ordered by PCPs in 1569 patients. Overall, 846 patients complied and received FOBT cards, which represents an overall 53.9% compliance rate (Fig. ). Of the 769 eligible participants, 435 (56.6%) returned the FOBT cards, and the absolute return rate was 64.4% in patients receiving a mailed reminder and 48.4% in usual care patients. Extrapolating this to the overall rate of successful FOBT compliance in the total group for which FOBT testing was ordered, the use of a mailed reminder may increase overall FOBT compliance from 409/1569 (26.1%) to 545/1569 (34.7%), which again represents a relative increase of 33%. Again, this presumes that FOBT testing was ordered for the purpose of CRC screening in all 1569 patients, but data are not available to verify this in all patients who did not comply with FOBT and not included in the study.
A prior review of participation in CRC screening documented overall FOBT compliance rates ranging from 10% to 50%, depending on the study population, setting, and type of intervention9
. In three randomized trials, the compliance rates of selected patients that agreed to undergo FOBT testing were 59.6% to 75.2%3,4,18
. In contrast, compliance was much lower in community based mass screening programs, ranging from 26% to 48%11,12,19,20
Various patient interventions have been studied to increase FOBT compliance including telephone reminders, postal reminders, letters signed by personal physicians, and other educational strategies9
. However, despite the most intensive strategies delivered to well-defined populations of eligible patients, overall FOBT adherence rarely increased above 50%9
. More recently, Stokamer et al. conducted a randomized, controlled trial to examine whether intense patient education from nurses would increase FOBT card return rates in U.S. Veteran patients11
. The investigators were able to show that a one-on-one 10–15 minute educational session regarding the importance of CRC screening and FOBT by nurses increased FOBT completion rates to 65.9% compared with 50.1% in the control group. Despite the significant increase in FOBT completion rates, implementing this intervention would likely be expensive and time-consuming.
Prior studies of mailed reminders for improving CRC screening rates have shown mixed results, with minimal improvement documented in unselected patients21,22
. More recently, although not related to FOBT adherence, Denberg et al. were able to show that a 1 page 2-sided mailed reminder significantly increased colonoscopy appointment adherence by 11.7% and was cost-effective16,23
. The study participants in Denberg’s randomized controlled study were non-volunteers and were blinded to their involvement.
Limited data have been published describing patient-related factors that are associated with compliance and non-compliance with FOBT based screening. Using our diverse and large cohort, we identified several independent predictors of FOBT compliance, which include having received a mailed reminder and prior history of FOBT completion. The only negative significant factor associated with FOBT compliance was current or recent illicit drug use.
In our pooled sample, patients who had completed one, two, or three or more FOBT kits in the past were more likely to return the FOBT than those who had never completed an FOBT kit. Our observation of prior FOBT completed as a positive predictor of FOBT completion is not surprising. Patients who have completed the test in the past are more likely to be unaffected by the process of collecting their own stool samples, which has been shown to be one of the major barriers to FOBT compliance24
. We also found that patients who were currently or recently using illicit drugs were 74% less likely to return the FOBT cards than non-illicit drug users. This observation again is not surprising because patients who continue to participate in risky behaviors such as illicit drug use may lack interest in their own healthcare. To our knowledge, this is the first study to show current or recent illicit drug use as a significant negative predictor of CRC screening. It is likely that illicit drug use is much more prevalent than our study reports due to the lack of systematic reporting and questioning from physicians and the refutation by patients. These data indicate that providers should take steps in addressing their patients’ current or recent illicit drug use, while at the same time take extra steps to encourage CRC screening.
The strengths of our study include: the simplicity and low cost of the intervention; the large sample size; blinded, randomized control design; low exclusion criteria; long-term follow up allowing adequate time for participants to return the FOBT cards; and a comprehensive computerized medical record system to identify predictors of compliance. This study also has several limitations. First, we only enrolled patients who picked up their FOBT cards at the laboratory after their PCP visit, and do not report the overall compliance with FOBT testing ordered by PCPs. However, we have made some estimates of overall compliance as indicated above. Second, our sample was comprised of U.S. Veteran patients from San Diego, California, which limits the generalizability of our findings. For example, financial barriers for VA patients may be less than a population with lower levels of health insurance. Third, our study was unable to determine the relative degree to which compliance was influenced by the reminder itself, the patient quote regarding CRC screening, or the educational facts regarding CRC. Fourth, we did not exclude any patients over the age of 75 as recommended by the USPSTF in 20085
, because our study was performed prior to these recommendations. Lastly, current guidelines call for the use of more sensitive albeit more expensive fecal immunochemical tests and potentially DNA testing; however these methods of screening have not yet been widely adopted. The results of this study would be highly relevant for these tests and would help enhance the cost-effectiveness of this approach to CRC screening.
In summary, a simple, inexpensive mailed educational reminder significantly improved FOBT card return rates for CRC screening. A factor associated with FOBT noncompliance is current or recent illicit drug use; and steps to address these issues are warranted. The results of this study also indicate that further improvements in patient compliance with CRC screening are needed. Whether adding another reminder would increase patient compliance further is an important topic for future investigation. Further studies are also recommended to assess the impact of other educational or motivational techniques, such as e-mail reminder, cell phone text messaging reminders, or specific incentives for compliance with cancer screening tests.