Examining the Cost-Effectiveness of Introducing Patient Navigation Services for Colorectal Cancer Screening Among a Low-Income and Uninsured Population.

Introduction
Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States (U.S.).
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The 5-year survival rate for those diagnosed at an early stage is 91%, while it decreases to 13% when diagnosed at a distant stage.
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This difference highlights the importance of early detection via CRC screening to enhance survival and decrease potentially high medical expenditures for cancer treatment.2,3 Despite the benefits of CRC screening, only about 70% of US adults aged 50 to 75 years adhere to the United States Preventive Services Task Force (USPSTF) CRC screening recommendations, which is less than the National Colorectal Cancer Roundtable (NCCRT) goal (80%).4,5 The issue of CRC screening non-adherence is exacerbated among the uninsured population, who generally face socioeconomic challenges accessing preventive medical services.
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The persistence of low CRC screening rates and high CRC-related mortality among underserved populations necessitate urgent measures to promote CRC screening to increase screening rates.7,8 However, promoting CRC screening adherence for underserved populations is particularly complex because there are intricate contextual barriers to screening, such as lack of facilities, trained clinicians, cognitive factors, education, and stigma, which hinder the ability of these populations to adhere to the screening recommendations.
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Many researchers focus on promoting CRC screening via expanding public coverage programs, developing paid leave policies, and addressing social factors affecting poor CRC screening outcomes, but studies of programs that promote CRC screening uptake among the uninsured are limited.10,11 In particular, there has been little attention on local community-level interventions led by well-trained community health workers (CHW) to help overcome barriers to CRC screening among uninsured populations.
The impact of community-oriented strategies on promoting CRC screening rates among low-income and underserved populations remains unknown. The numerous barriers to CRC screening in this population, such as lack of screening facilities nearby, lack of CRC risk awareness, negative attitudes toward CRC screening, inadequate physician recommendations, language obstacles, and cultural beliefs (stigma and negative attitudes toward CRC), collectively contribute to delayed or missed screenings, resulting in poorer prognosis after being diagnosed with cancer.9,12-14 The involvement of CHWs in disease screening promotion has been recognized as a promising strategy for mitigating these critical challenges.15,16
Community health workers are expected to play a critical role in assisting individuals in overcoming these barriers and enhancing their access to CRC screening services within local communities.15,16 By engaging with underserved populations, Community health workers can build trust, disseminate CRC education and promoting screening participation to contribute to improved CRC outcomes through tailored approaches designed for the local community.15,16 These efforts enhance cancer awareness, encourage timely health-seeking behaviors, and connect individuals to clinical care—ultimately promoting cancer screening and early detection. The available evidence suggests that active community engagement events in CRC screening can help overcome cognitive barriers and enhance screening rates among underserved populations effectively.15,16 For example, community CRC screening engagement events have been shown to improve understanding of CRC screening recommendations and increase adherence to recommendations.
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Moreover, well-implemented referral systems between community and clinical sites can play a proactive role in reducing barriers to accessing screening facilities for underserved populations.
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Research suggests that patient navigation services, which address social determinants of health, are highly effective in promoting CRC screening.18,19
A recent systematic review has shown that CHW interventions significantly improve colorectal cancer CRC screening uptake among U.S. racial and ethnic minorities, including Chinese Americans, Hispanics, Vietnamese, African Americans, Filipinos, and Hmong populations. Multicomponent CHW interventions are particularly effective.
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In the U.S., CHW programs not only enhance screening rates at a low per-participant cost but are also cost-saving from a cost-per-QALY perspective.
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In contrast, similar outcomes were not observed in the U.K. or France, possibly due to differences in healthcare systems.
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These findings highlight the critical role of CHWs in promoting cancer screening adherence among underserved populations in the U.S. However, there is limited research evaluating the cost-effectiveness of patient navigation services for the low-income and uninsured population in the United States.

Study Objective
This study evaluates the cost effectiveness of CHW navigation services for promoting CRC screening among a low-income and uninsured population, thereby improving their long-term CRC outcomes. A decision model is constructed to assess the impact of the CHW intervention on the rate of CRC screening among uninsured persons, compared with the rate of screening without the intervention, starting at age 45, as recommended by USPSTF.
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For both groups, the long-term cost and health effects for those who are screened and those not screened are projected using published estimates of incremental costs and life-years (LYs) gained for a market-share-weighted average of four CRC screening modalities: Fecal immunochemical test (FIT), High-Sensitivity Guaiac-Based Fecal Occult Blood Test (HSgFOBT), multitarget stool DNA test including FIT test (sDNA-FIT), and colonoscopy.
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A decision model is used to calculate an incremental cost-effectiveness ratio (ICER) to assess the net additional cost of the CHW intervention relative to LYs gained from the improvement in CRC screening rates attributable to the CHW intervention.

Methods

Population Studied
The CHW navigation program evaluated in this study focused on improving CRC screening in a low-income and uninsured population living in medically underserved areas of Texas. According to the CDC, the CRC screening rate among the uninsured was 39% in 2020, which was significantly lower than the CRC screening rate of 75% among the insured in the United States.
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The hypothetical cohort evaluated in the model represents a population of low-income and uninsured adults aged 45 to 75 years at average risk for CRC, for whom CRC screening is recommended using any of the screening modalities approved for persons at average CRC risk by the USPSTF.
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Intervention
This study focuses on CHWs trained to deploy a tailored CHW navigation model to promote cancer screening, including CRC screening, among the low-income uninsured and underinsured population in underserved areas. The navigation plan design and implementation have been operated by the Texas A&M University School of Medicine, School of Nursing, and School of Public Health with clinical support by the Texas A&M Health Family Care Clinic, beginning in 2013.
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The following summary of the operation of the CHW program intervention is based on interviews we conducted with several CHW program participants between May 2023 and July 2023.
In this program, most CHWs are either native or fluent Spanish speakers, allowing them to effectively connect with the target minority populations, particularly in rural Texas. CHWs may join with or without prior experience and receive comprehensive training led by experienced CHWs, both through literature-based instruction and hands-on community engagement. CHWs identify target populations through collaboration with academic institutions, clinical partners, and participation in local outreach events. They engage with the community by attending local gatherings, partnering with vendors and local grocery stores, and distributing educational brochures. Additionally, the program promotes free cancer screening services through indirect media channels such as newspapers, podcasts, and TV segments.
As shown in Figure 1, the CHW navigation program includes five major steps to build up a streamlined navigation service for promoting CRC screening among low-income and uninsured populations. The initial step involves identifying the target population with low CRC screening rates and then designing a tailored navigation strategy to engage with them effectively. Regular weekly meetings ensure alignment with engagement objectives and allow for adjustments in strategies as needed, thereby optimizing the effectiveness of CHW interventions. The second step focuses on empowering CHWs through comprehensive training initiatives. New CHWs receive monthly sessions and receive ongoing education updates related to CRC, ensuring they are well-informed and equipped to provide up-to-date screening information. This approach fosters stronger connections with potential participants and enhances their ability to engage and educate effectively.
In the third step, the team collaborates with community partners to organize direct and indirect outreach events. For direct outreach, patient navigation methods are developed, and various community partners, including health fairs, food pantries, resource centers, and local grocery stores, are engaged to attract potential participants. Additionally, clinical sites are involved to ensure CHWs possess the latest screening information and establish a referral system connecting CHW navigation with screening facilities. Informative materials such as cancer screening brochures and health education resources are distributed, along with informal counseling, to enhance cancer prevention knowledge among participants. Indirect outreach is also undertaken through diverse media platforms, with partnered physicians and CHWs disseminating screening information via radio, newspapers, and social media, thereby broadening the program’s reach, and encouraging more individuals to seek screening services.
The fourth step involves clinical site CHWs playing a crucial role in the cancer screening process by offering education sessions, conducting focus groups, providing navigation services, sending patient reminders, offering provider consultations or referrals, and conducting knowledge assessments for participants. Finally, the fifth step entails monthly team meetings and the generation of quarterly and annual reports to plan strategies and measure progress toward grant goals, which aim to enhance the quality of health services, particularly cancer screening, for low-income populations in Texas. The CHWs customize colorectal cancer navigation services to encourage CRC screening among the uninsured population. By implementing navigation services, the program is intended to reduce disparities in colorectal cancer screening and establish a sustainable and effective intervention for cancer prevention and early detection among vulnerable populations.
The cost-effectiveness model projects the net present value of medical care costs and expected life-years in with or without the CHW program for a cohort of 1000 uninsured individuals using a lifetime model horizon. The process used to calculate projected costs and effectiveness with and without the CHW program is shown in Figure 2. The net lifetime cost and expected life-year assumptions for being screened or not screened were derived from the published literature reporting net costs and life-years gained for various CRC screening modalities compared to no CRC screening. The decision model defines the form of CRC screening received as a market-share-weighted average of four specific USPSTF-approved CRC screening modalities: Fecal immunochemical test (FIT), High-Sensitivity Guaiac-Based Fecal Occult Blood Test (HSgFOBT), multitarget stool DNA test including FIT test (sDNA-FIT), and colonoscopy. The weights are based on approximate shares of the four alternative modalities observed in nationwide data from commercial and public insurance programs in the United States (ie, FIT 18.9%, HSgFOBT 6.6%, sDNA-FIT 14.2%, and colonoscopy 60.3%).
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The model assumes the CHW intervention increases the rate of CRC screening but does not alter the mix of screening modalities employed among those screened.
The estimated ICERs were calculated as the difference between projected lifetime costs for the 1000-person cohort with and without the CHW program, divided by the difference in projected life-years for the 1000-person cohort with and without the CHW program. Cost-effectiveness was assessed assuming CRC screening starting at age 45, based on updated CRC screening recommendations.

Program Effectiveness Assumption
The primary outcome of the CHW program of interest for the cost-effectiveness model is the improvement in patient adherence to CRC screening recommendations due to the intervention of CHWs among the uninsured population. The assumed probability of being screened without the CHW program is 39%, based on the CRC screening rate of 39% among the uninsured in 2020.
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The assumed effectiveness of the CHW navigation program in improving the screening rate in the uninsured population is based on an evaluation of the impact of the navigation services provided by Texas A&M University under a program funded by the Cancer Prevention Research Institute of Texas. The CSTEP program includes uninsured or underinsured, low-income individuals aged 45 to 75, in line with CRC screening recommendations, as well as those younger than 45 or older than 75 who are at increased risk due to personal or family history of colorectal cancer.
From June 1, 2022, to May 31, 2023, Community Health Workers in the program directly provided navigation services to 3196 unique individuals. As noted previously in the description of the intervention, potential participants in the CHW navigation program were identified in collaboration with community partners to organize direct and indirect outreach events. There are no reliable data on the demographic characteristics of the uninsured population in Texas within the relevant age range, so the representativeness of the study’s convenience sample cannot be fully assessed. However, as shown in Table 1, among the recruited participants, 6% were aged below 45, 86% aged 45 to 64, and 8% were aged 65 or older. Notably, 72% identified as Hispanic or Latino, and 65% reported Spanish as their primary language. The majority were married, had a household size of fewer than five members, and had attained a high school education or less. Approximately 90% resided in metropolitan areas.
Navigation services provided by CHWs through the program resulted in 536 unique participants (17%) receiving CRC screening, but 58 of these 536 participants reported having a previous CRC screening test within the past 5 years, leaving 478 (15% of the total) as non-compliant to regular CRC screening recommendations. However, at least some of the 478 newly screened participants would have been screened without the CHW navigation program. The base-case model assumes that 61% of newly screened participants would not have been screened without the CHW program, based on the overall CRC screening rate of 39% in this population (100% − 39% = 61%). This approximation yields an estimated improvement in the rate of CRC screening of 9 percentage points (61% × 15% = 9%) among those previously non-adherent to CRC screening guidelines potentially attributable to the CHW intervention. This estimate was rounded to a 10 percentage-point improvement for the base-case model and then varied from 2.5 percentage points to 15 percentage points in the sensitivity analyses.

Life-Years Gained Assumption
Our cost-effectiveness model builds upon the framework established by the Cancer Intervention and Surveillance Modeling Network (CISNET) that is used by the USPSTF to assess the lifetime health benefits and costs of CRC screening.
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This framework incorporates numerous factors, including initial and end age, screening frequency, modality, number of life-years gained, colorectal cancer cases and deaths averted, lifetime colonoscopies required, and potential harms associated with different CRC screening strategies. Our model focuses on four recommended screening modalities: FIT every year, HSgFOBT every year, sDNA-FIT triennially, and colonoscopy every 10 years. For simplicity, other screening modalities were excluded from the analysis because they are rarely used. The primary measure of health benefits in our model is the expected gain in life-years for average-risk adults who are screened, as compared with those not screened, starting at age 45. To evaluate the effectiveness of the navigation model, as noted, we defined a weighted-average composite of CRC screening strategies, based on observed shares in nationwide data from commercial and public insurance programs in the United States.
As shown in Table 2, the USPSTF model concludes that initiating annual FIT at the age of 45 for a cohort of 1000 individuals would result in an additional accrual of 318 life-years gained over a lifetime horizon, compared to no screening.
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In addition, adopting a screening approach involving annual HSgFOBT, triennial sDNA-FIT, and colonoscopy every 10 years, starting at age 45 would yield gains of 298 303 and 337 life-years, respectively.
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Using the assumed modality shares, the weighted average LYG from screening compared with no screening starting at age 45 is 326 years for a 1000 person cohort, or 0.326 LYG per person.
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Appendix A shows that the implementation of CRC screening starting at age 45 is projected to prevent 50, 42, 57, and 61 cases of CRC among 1000 individuals at average risk over a lifetime horizon for screening using FIT, HSgFOBT, sDNA-FIT, and colonoscopy, respectively.
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Based on the USPSTF model, the weighted average projected effect of the four CRC screening strategies initiated at age 45 would be to avert 28 CRC-related deaths among 1000 individuals at average risk, respectively. All these cost and effectiveness estimates assume that the specific initial CRC screening modality employed is maintained over time, meaning that subsequent testing intervals and follow-up care adhere to recommendations from age 45 to 75.

Cost Assumptions
The direct cost associated with the implementation of the CHW navigation service was retrospectively gathered from the Cancer Prevention and Research Institute of Texas (CPRIT) program that utilized CHWs to promote CRC, breast, liver, and skin cancer screening for the uninsured population in Texas.
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Program expenditures included the cost of navigation services, which encompassed CHW training, outreach and stakeholder engagement, consultation for participants, referral, clinical site support, evaluation, materials (brochures and stationery), employee insurance, faculty evaluation for assessing residents’ socioeconomic and insurance status, and marketing through broadcasting and newspapers. Program cost estimation was based on CHW salaries, cost of materials, outreach expenses (including newspaper and broadcasting costs), and insights from stakeholder interviews to determine the time allocated to tasks within the colorectal cancer screening project retrospectively. The value of time was estimated based on the average hourly salary for each role in the project, as detailed in Table 3. The hourly rate CHWs was estimated as $16/hour for contract CHWs and $20/hour for trained and experienced full-time CHWs.
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The salary level was based on their work experience and whether the CHW had received specific training for cancer screening.
The cost of CHWs for the program depended on their salary and the number of hours spent participating in CHW meetings, outreach programs, training programs, and travel expenses for CHWs. Program expenditures are divided into four segments: (1) assessment of outreach and engagement needs; (2) CHW training, outreach and engagement; (3) clinical site support; and (4) evaluation. Each of these segments requires allocation of CHW workload attributable to the promotion of CRC screening among other cancer screening initiatives. Overall, it is estimated that the assessment of outreach and engagement needs required the engagement of two full-time CHWs working 60 to 80 hours per month at a rate of $20 per hour, along with the engagement of six independent CHW contractors working 8 hours per month at a rate of $16 per hour. This training regimen necessitates 4 hours of engagement per week for each of the six fixed-time CHW contractors, with an additional 2 to 8 hours per month per contracted CHW as needed. Each full-time clinical CHW will be expected to work 160 hours per month. During evaluation sessions, the engagement of a full-time PhD-level evaluator, such as an Assistant Professor from the School of Medicine, is necessary. The median salary for such a position in Texas is approximately $100 000 per year, equating to a rate of $45 per hour.
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Additionally, a full-time CHW working 20 hours per month will be required to assist with evaluation tasks.
The marketing expenditure was estimated based on an interview with the Program Manager for this program. The brochure of CSTEP free cancer screening events is estimated to cost $0.14 each, and an estimated 5000 brochures were used for engagement events per year.
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Finally, the estimated costs of office supplies and insurance are based on estimates for small business
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(ie, $1069/person/year for 3 CHWs located in fixed office sites) and 10 full-time and part-time CHW employees’ health insurance ($8182/year).
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The overall estimated cost of the CHW program was $283 951. The CHWs were engaged in promoting screening for four cancers: colorectal cancer, breast cancer, liver cancer, and skin cancer. The model assumes that the overall cost is allocated equally to these four cancers, resulting in an overall cost estimate of $70 988 for promoting CRC screening. The CHW promotional effort was associated with 536 program participants receiving CRC screening, which yields an estimate of $132 per person screened. Sensitivity analysis varies the estimated cost per person screened from $66 to $528.
The present value of the direct cost of CRC screening for those screened includes costs for CRC screening procedures, CRC cancer treatments, and related health services over time. The assumed present value of the cost of CRC screening per person for each of the four screening modalities was obtained from published literature. The assumed present value of lifetime CRC cost per person in 2023-equivalent dollars for those not screened was $5554, whereas the assumed lifetime per-person cost for FIT, colonoscopy, sDNA tests, and FOBT at age 45 was $3757, $5465, $7473, and $6096, respectively.31,32 The reference lifetime cost estimates are discounted at an annual rate of 3%, in accordance with the methodological guidelines outlined in the “Recommendations for Conduct, Methodological Practices, and Reporting of Cost-effectiveness Analyses.”
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Analysis
The base-case parameterization of the model was used to calculate ICERs for the CHW intervention, compared with usual care (no navigation program), for CRC screening starting at age 45. Alternative scenarios were evaluated as a series of one-way sensitivity analyses. For example, the base-case assumption that the CHW intervention improved overall CRC screening rates in the target population by 10 percentage points was varied from a low of 2.5% to a high of 15%. Similarly, sensitivity analyses varied the base-case assumption of $132 in CHW implementation costs per person screened from $66 to $528 and varied the projected LYG and net cost of screening compared with no screening per person from 75% to 125% of the baseline assumption. Two-way sensitivity analyses for selected scenarios were also performed. All model analysis was conducted using Microsoft Excel version 16.66.1.
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Results
Table 4 presents the base-case model estimates of the present value of lifetime costs, defined as lifetime costs of CRC treatment and lifetime costs of screening if screened, and the projected gain in life expectancy from screening (versus no screening) for model cohorts with and without the CHW navigation intervention for CRC screening starting at age 45. The higher costs and improved LYG estimates for the CHW program intervention reflect the role of the CHW program in increasing the share of cohort members who receive CRC screening compared with no screening.
Under base-case assumptions, CHW promotion of CRC screening for the uninsured population starting at age 45 is expected to result in a gain of 0.160 life-years per person. If the CHW intervention improves the CRC screening rate by 10 percentage points, based on a weighted average of previously published cost estimates across four modalities of CRC screening, the present value of lifetime costs is estimated as $5672 per person in the intervention cohort. For the usual care (no intervention) cohort, with an assumed 39% CRC screening rate, the present value of lifetime costs is $5554 per person.
The estimated ICER for the CHW program, obtained by dividing the additional expenditure from the intervention by the increase in life-years gained resulting from improved CRC screening rates, is $3611/LYG under base-case assumptions. This suggests that the CHW program improves adherence to CRC screening recommendations among an uninsured population with an incremental cost per life-year gained well below the traditional willingness-to-pay threshold of $50 000/LYG. However, it should be noted that “$50 000/LYG” is essentially an arbitrary benchmark thought to derive from historical cost-effectiveness analyses of dialysis for end-stage renal disease in the 1970s, and may be considered a conservative willingness-to-pay benchmark if for no other reason it has not been adjusted over time for inflation.
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Nonetheless, it remains the most cited standard for cost-effectiveness analysis in the United States.
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One-Way Sensitivity Analysis
Key base-case model parameter assumptions were modified one at a time to provide one-way sensitivity analyses. Table 5 illustrates the impact on estimated ICERs from changing the assumed effectiveness of the CHW navigation service from a 2.5, 5.0, or 15 percentage-point increase in CRC screening adherence rates, and from increases and decreases from base-case values for the assumed costs of the CHW program per person, costs of CRC screening, and LYG compared. The ICERs under alternative assumptions about program effectiveness in improving patients’ adherence (2.5, 5, or 15 percentage point increase) range between $2262 and $15 758 per LYG. ICERs assuming program costs are $66, $264, $396 or $528 per person range from $1587 to $15 758 per LYG.
Assuming the projected lifetime cost of screening is 75% of the base-case assumption results in net cost savings starting, whereas assuming lifetime costs of screening are 125% of the base-case assumption, the estimated ICER is $7804/LYG. None of the ICERs for the CHW intervention in these alternative model scenarios exceed the traditional WTP threshold of $50 000 per life-year gained. This finding suggests that a program utilizing CHWs to promote CRC screening is likely to be cost-effective across a variety of plausible model scenarios.

Two-Way Sensitivity Analysis
To further assess the robustness of the model results to the assumed values for key model parameters, Table 6 presents the estimated ICERs for model scenarios altering base-case assumptions for CHW program cost and program effectiveness at the same time. A “worst case” scenario, which assumes a 2.5 percentage point increase in the CRC screening rate resulting from the CHW intervention and a program cost of $528 per person, resulted in ICERs of $64 346/LYG, whereas for a “best case” scenario, which assumes program costs of $66 per person and a 15 percentage-point increase in CRC screening adherence rate and the ICER results in an ICER of $912/LYG.
The two-way sensitivity analysis shows that increases in assumed program cost have a meaningful impact on ICERs when the CHW program is assumed to be relatively ineffective in improving CRC screening rates (ie, increase screening rate by 2.5 or 5 percentage points). Conversely, the ICERs are more robust to changes in assumed program costs if the CHW program is assumed to be relatively more effective (ie, a 15 percentage-point increase in CRC screening rates).
Results for additional two-way sensitivity analyses focused on the assumed net cost and effectiveness of CRC screening, compared to no screening, are reported in Table 7. The estimated ICERs for the CHW program are sensitive to the assumed net cost of CRC screening (75% or 125% of the base-case net cost assumption) and the assumed value of LYG from screening vs. no screening (75% or 125% of the base-case LYG assumption). However, across all two-way scenario changes, the estimated ICERs are below the usual $50 000/LYG WTP threshold, and scenarios with lower assumed screening costs coupled with higher assumed CHW program effectiveness suggest the CHW intervention may be cost saving.

Discussion
This study aimed to explore the implementation of CHW navigation services for a low-income and uninsured population and assess its impact on patients’ adherence to CRC screening recommendations. According to estimates provided by the CSTEP CHW program, approximately 56 000 individuals would be indirectly exposed to colorectal cancer education and screening information dissemination within a year. Additionally, an estimated 4000 potential patients would receive direct exposure to this educational content and screening information.
Our findings suggest that introducing CHW navigation programs for an uninsured population starting at age 45 is cost-effective (ICERs under a $50 000/LYG WTP threshold) under most model scenarios using plausible assumptions about the effectiveness of the CHW program, CHW program costs per person, the present value of lifetime costs of CRC screening, and LYG from CRC screening versus no CRC screening. Under “worst-case” scenarios for CHW program costs and effectiveness, estimated ICERs are approximately equal to the traditional $50 000/LYG threshold, whereas under “best-case” scenarios, the CHW program is projected to be cost saving. Racial minorities have the highest proportion of uninsured individuals and face the greatest risk of being diagnosed with colorectal cancer (CRC) at a later stage.37-39 These populations often have unique characteristics and face specific barriers at both the individual and provider levels, which may differ from the scenario addressed by this CHW program intervention.40-49
To address the heterogeneity of disadvantaged groups challenges, patient navigation services play a crucial role in promoting compliance with CRC screening among underserved populations through culturally specific interventions such as consistently endorsed by minority community leaders to facilitate patients’ acceptance and understanding of the screening procedures, thereby increasing their compliance with screening recommendations and follow-up care.49-55 Hence, patient navigation services are not only effective tools for promoting health but are also indispensable in multicultural communities. In our model, the ICERs for implementing patient navigation services to promote CRC screening are below the usual WTP thresholds. This highlighted the cost-effectiveness and feasibility of such interventions among uninsured populations.
While there may be concerns that the effectiveness of this CHW navigation program could vary due to regional differences in uninsured populations and the inherent heterogeneity in CHW program implementation, systematic reviews have consistently demonstrated the effectiveness of CHW interventions across diverse minority populations in both rural and urban settings.
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Mojica et al
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reported that Community Health Worker (interventions increased colorectal cancer screening uptake by 12% to 20% among Vietnamese and Latino populations. Similarly, Feltner et al
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found that educational interventions for adults residing Appalachian areas improved patient-physician relationships, reducing barriers such as low cancer awareness, discomfort, and embarrassment associated with CRC screening. Additional evidence demonstrates that CHW-led education combined with navigation services not only enhances screening rates but also contributes to reductions in CRC incidence and mortality across diverse racial and ethnic minority populations.58,59 Consistent with prior evidence, our findings further support the feasibility of CHW navigation for uninsured minority populations in underserved areas and underscore its broader applicability in promoting cancer screening across various populations and contexts.

Limitations
While our study suggests the patient navigation model using CHWs among the low-income and uninsured population is likely to be cost-effective, it is important to acknowledge several limitations. Uninsured populations often live in underserved regions with limited CRC screening facilities and health workers, which can significantly influence navigation service expenditures based on accessibility to health services, local labor costs, and relevant policies.60-63 The estimated program expenditure in our analysis is based on a pilot study in central Texas, which may not reflect the program cost per person in a larger scale patient navigation program implementation within Texas, and may not represent likely navigation program costs for the rest of the United States.
This study used estimates of life-years gained and lifetime cost of CRC-related medical services produced by USPSTF, which is a source of two key limitations. The first is that the USPSTF estimates are derived from decision models that assume individuals who initiate a specific CRC modality (eg, colonoscopy) will adhere to recommendations for that modality over time (eg, repeat colonoscopies at recommended intervals). However, in usual practice, many individuals do not adhere to follow-up recommendations, or they may switch from one screening modality to another over time. As a result, the model may overestimate the life years gained from improvements in initial CRC screening rates and underestimate the increase in lifetime CRC costs for the intervention cohort.
Another limitation is that the USPSTF estimates are based on the racial distribution of the entire population in the United States: non-Hispanic White (58.9%), Black (13.6%), Hispanic (19.1%) and Other races (8.4%).
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However, for the uninsured population in the United States, about 45% are White, 14% are Black, 34% are Hispanic, and approximately 8% are other races.
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Variations in genetic predispositions, adenoma polyp occurrence rates, CRC incidence, histology types, and responses to treatment across racial and ethnic groups further contribute to wide variation in cost estimations. Many African-Americans have genetic risk factors leading to a higher occurrence of CRC, more aggressive progression of CRC, and lower response to cancer therapies.
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The incidence and mortality rate of CRC are highest among African American and American Indian (41.9/100 000 and 39.3/100 000, respectively) and lowest among Hispanic and Asian (16.8/100 000 and 14.0/100 000, respectively).
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In addition, Hispanic, AI/AN and African American have 21% to 23.2% higher probability of receiving CRC diagnoses at a late stage; meanwhile, Black and AI/AN populations have significantly worse CRC survival rates than White populations.60,67-69 The variation of these risk factors across races contributes to disparities of CRC prognosis and relevant expenditure which further results in uncertainty of effectiveness estimates.
Finally, we used the estimated improvement in CRC screening adherence rates based on patient navigation services provided to low-income, uninsured populations in Central Texas, using a small sample size. Most participants were Hispanic and resided in Health Professional Shortage Areas (HPSAs). Power analysis was not performed in this study, which may limit the generalizability of the findings. In addition, we specifically offered free FIT and colonoscopy as components of the navigation services. However, it is crucial to acknowledge that the effectiveness of patient navigation services may vary based on factors such as race, CRC screening strategies, and geographic location, leading to a wider range of estimated effectiveness for patient navigation programs. Research indicated that the utilization of navigation services for both American Indian and tribal communities increased the knowledge of CRC screening and consequently increased 37 percentage point increase in the CRC screening rate.
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In addition, the navigation service with different screening strategies (FOBT or colonoscopy) show a significant difference in increased CRC screening adherence among African American with adequate health literacy.
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Another clinical trial also shows traditional patient navigation did significantly promote the use of endoscopic but not stool-based screening among the senior Latino population, while mobile navigation service did improve the uptake of FIT for Hispanic and AI/AN adults.72-74 Based on the evidence presented, the effectiveness of patient navigation services varies across different races, barriers and CRC screening procedures. This variation in effectiveness may lead to a wider difference in estimated service effectiveness and estimated LYG, which limits this study’s generalizability. In this study, we conducted one-way and two-way sensitivity analyses, adjusting the variance of program cost, life-year gain and program effectiveness estimates. This approach enabled us to evaluate a range of potential and address uncertainties in estimation.

Conclusion
Although detecting colorectal cancer at an early stage can reduce harm, less than 40% of the uninsured population in the United States aged 50 to 75 years follow CRC screening recommendations. It is critical to develop a tailored screening protocol targeting underserved populations. In this study, our model results suggest that implementing patients’ navigation services starting at age 45 and 50 for these marginalized populations would be cost-effective under numerous model scenarios. By considering the variations in estimated program expenditures and the expected improvement in adherence rates of patient navigation services, this research may provide insights into the widespread application of analogous programs across different states, funding agencies, and relevant research institutions. In this study, the estimated startup cost for implementing a Community Health Worker program to promote four cancer screening services and reach approximately 4000 underserved individuals within a year is around $70 000. However, program costs and effectiveness may vary based on the number of individuals reached, the degree of program tailoring, population characteristics, local CHW salaries, and the ongoing resources required to support CHW program operations. To ensure long-term impact, policymakers should prioritize the scalability and sustainability of CHW programs, particularly in efforts to improve colorectal cancer screening adherence among uninsured and underrepresented populations.