Introduction

Burden of Colorectal Cancer

In the USA, colorectal cancer (CRC) is the third most common cancer in both men and women [1]. The overall incidence of CRC in Harris County Texas is 41.8 per 100,000, which is higher compared to the Texas incidence of 40.2 per 100,000 [15]. This is much higher than the goal of 38.6 per 100,000 recommended by the Centers for Disease Control (CDC) and Prevention and the National Institute of Health (NIH) in the Healthy People 2020 objectives [35]. CRC is the second leading cause of cancer-related deaths among male and female residents of Harris County. In 2015, the number of new cases of CRC in Harris County was projected at 1055 (men, 570; women, 485) with 459 deaths [15].

CRC disproportionately affects African Americans; the overall age-adjusted incidence for CRC in African Americans in Harris County is 54.0 per 100,000 (68.2 per 100,000 men and 44.5 per 100,000 women). Furthermore, worse CRC outcomes are observed in African American women, possibly because of more aggressive tumors [33], which result in earlier distant spread, and ultimately death. CRC is the second most common type of new cancer diagnosed in Hispanics (41.8 per 100,000 men and 28.2 per 100,000 women). For Asians, CRC ranks third (42.4 per 100,000 men and 23.5 per 100,000 women). For non-Hispanic whites, CRC also ranks third in new cancers (51.7 per 100,000 men and 34.6 per 100,000 women). The overall mortality rate from CRC in Harris County is 15.6% (based on data from 2008 to 2012) [33]. This is higher than the goal of 14.5% that the CDC and NIH have put forth in the Healthy People 2020 objectives [35]. Other than biological factors, the prevalent view for differences in CRC incidence include delay in diagnosis, lack of insurance, and lack of knowledge and understanding about the benefits of early initiation of CRC screening. Additionally, previous experiences resulting in lack of trust in health care systems, and cultural beliefs about cancer, have been shown to contribute to major gaps in essential CRC screening services [3, 12, 22, 31]. For example, findings from community-based cancer screening interventions indicate a general sense of fatalism among African Americans regarding CRC outcomes [2, 18].

Rationale for the Literature Review

The impact of patient navigation on CRC screening has been evaluated in both community- and hospital-based interventions. The general assumption is that patient navigation is useful in helping patients adhere to CRC screening recommendations; however, concrete evidence for its effectiveness is still currently under investigation. One major limitation in previous studies has been the lack of inclusion of medically underserved patient populations, as well as differences in study design, which makes it difficult to make comparisons between studies. The present literature review was undertaken to explore the effectiveness of patient navigation and education on CRC screening completion in medically underserved populations.

Methods

Overview

We conducted a comprehensive search of the literature for studies that have included patient navigators as key strategy for improving completion and quality of CRC screening. This literature review involved the use of several search engines including PubMed, Google Scholar, and Cochrane reviews. The following terms were used to identify articles: patient navigation, colonoscopy, fecal occult blood test (FOBT), fecal immunochemical test (FIT), CRC screening and outreach, CRC screening and prevention education, racial/ethnic disparities in CRC, and patient-centered approaches to CRC care. In addition, manual searches were conducted of studies referenced in these publications. We included randomized controlled trials and prospective investigations that had an intervention and control group. Case series, brief communications, commentaries, case reports, and uncontrolled studies were excluded. In instances where authors had multiple publications that presented data on the same population, the most recent publication was considered. Literature reviews and studies that presented design of CRC patient education protocols without including findings were excluded from the review as well. The review is subdivided into several major themes: (1) racial/ethnic disparities in CRC screening, (2) CRC prevention and education strategies, (3) impact of patient navigation on CRC screening, (4) tailored CRC education, and (5) cost-effectiveness of patient navigation programs to improve CRC screening completion.

In order to conduct a comprehensive review of the methodology followed in each research study, the Consolidated Standards of Reporting Trials (CONSORT) guidelines was used [34]. The CONSORT checklist was used to review how studies were designed, analyzed, and interpreted. This checklist aided in the decision of which studies to include in the literature review.

Results

Overview

As can be seen in Fig. 1, 79 articles were initially identified. Of these articles, 43 did not mention CRC screening as main study outcome, did not specifically explore effectiveness of patient navigation on CRC screening, were concept papers, or presented policy statements. Another nine articles were excluded from the review because they presented literature reviews of studies conducted within the same time period evaluated in the present review, or were of poor methodological quality. In the end, 27 articles published in peer-reviewed journals between 2003 and 2016, were included in this review. Of these studies, 18 were RCTs [3–6, 8–14, 16, 20, 24, 25, 28–32, 38], five were descriptive or cross-sectional [7, 13, 17, 19, 23], and four were prospective studies [21, 27, 28, 38].

Fig. 1
figure 1

Study Flow Diagram

No. of articles identified through literature search (N = 79)

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Review of Studies Included in the Literature Review

Characteristics of the studies are outlined in Table 1. The main topics in the majority of publications were interventions that explored ways to change CRC screening behaviors in medically underserved populations. Some explored the utility of traditional provider-patient interactions as motivation to obtain CRC screening [9, 10, 14, 28]. Other studies implemented interventions that included tailored messaging [6, 10, 18, 21, 25, 32], lay and clinic-based patient navigation programs [5, 8, 11, 13, 14, 17, 26, 29, 30, 37, 38], and culturally and linguistically appropriate outreach and education efforts to meet the CRC screening needs of medically underserved individuals [3, 9, 16, 18, 26]. A total of four studies conducted cost-effectiveness analyses of their patient navigation program to improve CRC screening [7, 17, 20, 38].

Table 1: Characteristics of the 27 studies included in the review
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With the exception of studies conducted by Braschi CD, et al., Fiscella K, et al., Green BB, et al., Jandorf L, et al., Hendren S, et al., and Wells KJ, et al. in 2012 and 2016 [3, 8, 10, 17, 11, 37, 38], the majority of studies that had a patient navigation component demonstrated a positive impact on timely CRC screening [6, 9, 10, 13, 14, 26, 28–30, 33]. The patient navigation component in these studies included a number of barrier resolution services including help with transportation, health insurance, traditional patient reminder systems, and attention was given to implementing culturally and linguistically appropriate CRC education. For example, Pelto DJ, et al. [27], in a secondary analysis using data from two prospective PN cohorts, determined whether a patient navigation program targeted at African American and Latino participants helped increase CRC awareness and subsequently led to colonoscopy completion. In this study, a total of 742 African American and Latino patients were randomized to either a patient navigation or non-navigation arm. Patient navigation consisted of a health education intervention delivered in a culturally and linguistically appropriate manner. Patients in the navigation arm were significantly more likely to complete a colonoscopy compared to the non-navigation arm. In addition, language of health education instruction provided by patient navigators and patient income were significant predictors of colonoscopy completion. Similarly, Braschi CD et al. [3] explored the effect of a culturally appropriate patient navigation program targeted at a Latino patient population. Study groups consisted of patients randomized to a patient navigation group including tailored CRC education and a standard PN group (non-tailored). Key independent variables were socio-demographic and personal information. Main results revealed no significant differences in colonoscopy screening rates between the study groups. However, language acculturation and annual income above $10,000 were significantly associated with colonoscopy completion.

Green BB and colleagues [10] in a 4-group parallel-design RCT, examined whether the use of nurse navigation, EHR-linked mailings (automated), and combined automated with telephone assistance improved CRC screening over 2 years. Results showed that in comparison with usual care, EHR-linked mailings, and nurse navigation led to twice as many patients being current with CRC screening (usual care, 26.3%; EHR-linked, 50.8%; navigated, 64.7%).

In another study that explored the effectiveness of mailed CRC outreach education on completion of CRC screening, Singal AG, et al. [32] found that CRC screening was significantly increased among the mailed outreach group. In particular, FIT-based outreach was found to be more effective than colonoscopy-based outreach.

In another RCT, Meade CD, et al. [23] reported on experiences and lessons learned from implementing a lay patient navigator program to improve CRC screening completion among primary care medically underserved patients. Patient navigation was conducted by lay patient navigators and navigation services provided in six hospital-affiliated outpatient clinics and included barrier resolution services and helping to coordinate CRC care. Study population consisted of 588 Hispanic patients who predominantly spoke Spanish. The lay patient navigation program was effective in helping patients through a complex health care system. However, authors recommended a combination of lay and professional patient navigation to enhance coordination of CRC care, including completion recommended CRC screening. In an RCT conducted by Goldman S, et al. [9], 420 patients were randomized to either a PN outreach group or usual care. The goal of this study was to determine whether FOBT screening increased as a result of participating in the PN-led outreach intervention. Authors reported that intervention patients were significantly more likely to complete a fecal occult blood test compared to usual care (36.6 vs. 14.8%, p < 0.001, respectively). In addition, participants who visited the clinic often were more likely to complete the CRC screening test.

All cost-effectiveness studies included in this review have concluded that the use of patient navigation services as part of routine patient care are not only cost-effective, but can also generate revenue due to CRC screening completion. For example, Jandorf L, et al. [17] in a cost-effectiveness analysis of a colonoscopy patient navigation program included data from 503 multi-ethnic primary care patients 50 years and older, randomized to either a professional health education group or a community-based peer navigation group. Patient navigator salaries, supply costs, and navigation time were included in the cost-effectiveness analysis. Patient navigation resulted in 78.5% of patients completing a colonoscopy. Cost-effective analysis revealed that the patient navigation program resulted in a profit for the institution over a two-year period.

Conclusions

Peer-reviewed publications consistently indicate a positive impact of patient navigation programs on CRC screening completion as well have provided preliminary evidence for their cost-effectiveness. More well-conducted studies are needed that explore the use of EHRs in promotion of timely CRC screening and outreach.