Alternative approaches to assessing intervention effectiveness in randomized trials: application in a colorectal cancer screening study

Barriers to Colorectal Cancer Screening in US Immigrants: A Scoping Review

INTRODUCTION

Timely colorectal cancer (CRC) screening has been shown to improve CRC-related morbidity and mortality rates. However, even with this preventative care tool, CRC screening rates remain below 70% among eligible United States (US) adults, with even lower rates among US immigrants. The aim of this scoping review is to describe the barriers to CRC screening faced by this unique and growing immigrant population and discuss possible interventions to improve screening.

METHODS

Four electronic databases were systematically searched for all original research articles related to CRC screening in US immigrants published after 2010. Following a full-text review of articles for inclusion in the final analysis, data extraction was conducted while coding descriptive themes. Thematic analysis led to the organization of this data into five themes.

RESULTS

Of the 4637 articles initially identified, 55 met inclusion criteria. Thematic analysis of the barriers to CRC screening identified five unique themes: access, knowledge, culture, trust, health perception, and beliefs. The most cited barriers were in access (financial burden and limited primary care access) and knowledge (CRC/screening knowledge).

CONCLUSIONS

US immigrants face several barriers to the receipt of CRC screening. When designing interventions to increase screening uptake among immigrants, gaps in physician and screening education, access to care, and trust need to be addressed through culturally sensitive supports. These interventions should be tailored to the specific immigrant group, since a one-size-fits approach fails to consider the heterogeneity within this population.

Culturally-adapted behavioral intervention to improve colorectal cancer screening uptake among foreign-born South Asians in New Jersey: the Desi Sehat trial

Objectives: Colorectal cancer (CRC) is the third most common cancer among Americans of South Asian (SA) descent and is a significant public health concern in SA communities. Rates of screening compliance among foreign-born SAs are very low. The goal of this study was to report on the development, acceptability, and preliminary impact of a culturally-targeted 1:1 intervention delivered in English, Hindi, and Urdu, called Desi-Sehat.Design: Ninety-three foreign-born SAs between the ages of 50 and 75 were recruited using community-based organization methods. Participants completed a baseline survey, participated in a 1:1 session with a community health educator, and a follow-up survey was administered four months after the baseline.Results: The acceptance rate was moderate (52.8%). Attendance at the intervention session was high. More than half of the population did not complete the follow-up survey (58.7%). Participant evaluations of the intervention were high. Intent-to-treat analyses indicate a 30% four month follow-up CRC screening uptake. There were significant increases in knowledge and significant reductions in perceived barriers to screening, worry about CRC screening tests, and worry about CRC. Effect sizes for significant changes were in the medium to large range.Conclusions: Desi Sehat was a well-evaluated and participation in the session was high, participant knowledge significantly increased, and screening barriers, worry about CRC, and worry about CRC screening tests declined significantly. Future studies should focus on enhancing recruitment and retention and include a randomized control design.

Results of a lay health education intervention to increase colorectal cancer screening among Filipino Americans: A cluster randomized controlled trial

BACKGROUND

Filipino colorectal cancer (CRC) screening rates fall below Healthy People 2020 goals. In this study, the authors explore whether a lay health educator (LHE) approach can increase CRC screening among Filipino Americans ages 50 to 75 years in Hawai'i.

METHODS

A cluster randomized controlled trial from 2012 through 2015 compared an intervention, which consisted of LHEs delivering 2 education sessions and 2 telephone follow-up calls on CRC screening plus a CRC brochure versus an attention control, in which 2 lectures and 2 follow-up calls on nutrition and physical activity plus a CRC brochure were provided. The primary outcome was change in self-reported ever receipt of CRC screening at 6 months.

RESULTS

Among 304 participants (77% women, 86% had > 10 years of residence in the United States), the proportion of participants who reported ever having received CRC screening increased significantly in the intervention group (from 80% to 89%; P = .0003), but not in the control group (from 73% to 74%; P = .60). After covariate adjustment, there was a significant intervention effect (odds ratio, 1.9; 95% confidence interval, 1.0-3.5). There was no intervention effect on up-to-date screening.

CONCLUSIONS

This first randomized controlled trial for CRC screening among Hawai'i's Filipinos used an LHE intervention with mixed, but promising, results. Cancer 2018;124:1535-42. © 2018 American Cancer Society.

Lay health educators increase colorectal cancer screening among Hmong Americans: A cluster randomized controlled trial

BACKGROUND

Asian Americans have lower colorectal cancer (CRC) screening rates than non-Hispanic white individuals. Hmong Americans have limited socioeconomic resources and literacy. The current randomized controlled trial was conducted to determine whether bilingual/bicultural lay health educator (LHE) education could increase CRC screening among Hmong Americans.

METHODS

A cluster randomized controlled trial was conducted among Hmong Americans in Sacramento, California. LHEs and recruited participants were randomized to intervention or control groups. The intervention group received CRC education over 3 months delivered by an LHE. The control group received education regarding nutrition and physical activity delivered by a health educator. The outcomes were changes in self-reported ever-screening and up-to-date CRC screening after 6 months.

RESULTS

All 329 participants were foreign-born with mostly no formal education, limited English proficiency, and no employment. The majority of the participants were insured and had a regular source of health care. The intervention group experienced greater changes after the intervention than the control group for ever-screening (P = .068) and being up-to-date with screening (P<.0001). In multivariable regression analyses, the intervention group demonstrated a greater increase than the control group in reporting ever-screening (adjusted odds ratio, 1.73; 95% confidence interval, 1.07-2.79) and being up-to-date with screening (adjusted odds ratio, 1.71; 95% confidence interval, 1.26-2.32). Individuals who had health insurance were found to have >4 times the odds of receiving screening, both ever-screening and up-to-date screening. A higher CRC knowledge score mediated the intervention effect for both screening outcomes.

CONCLUSIONS

A culturally and linguistically appropriate educational intervention delivered by trained LHEs was found to increase CRC screening in an immigrant population with low levels of education, employment, English proficiency, and literacy. Cancer 2017;98-106. © 2016 American Cancer Society.

Agreement between self-reported and registered colorectal cancer screening: a meta-analysis

This random-effects meta-analysis investigates the accuracy of self-reported colorectal cancer screening history as a function of screening mode (colonoscopy, flexible sigmoidoscopy, faecal occult blood testing - FOBT, double-contrast barium enema - DCBE) and survey mode (written, telephone, face-to-face). Summary estimates of sensitivity, specificity, positive predictive value (PPV) and area under the receiver operating characteristic curve (AUC) were calculated. Medical record data were used as reference. We included 23 studies comprising 11,592 subjects. Colonoscopy yielded higher AUC [0.948, 95% confidence interval (CI) = 0.918, 0.968] than flexible sigmoidoscopy (0.883, 95% CI = 0.849, 0.911) and FOBT (0.869, 95% CI = 0.833, 0.898). Colonoscopy showed the highest sensitivity (0.888, 95% CI = 0.835, 0.931), whereas specificity was comparable between screening modes (ranging from 0.802 for FOBT to 0.904 for DCBE). AUC was not significantly different between survey modes. Prevalence of screening history correlated positively with sensitivity and negatively with specificity, possibly because of errors in the medical records. In conclusion, the accuracy of self-reported cancer screening is generally moderate, and higher for colonoscopy than for sigmoidoscopy and FOBT.

Binary variable multiple-model multiple imputation to address missing data mechanism uncertainty: application to a smoking cessation trial

The true missing data mechanism is never known in practice. We present a method for generating multiple imputations for binary variables, which formally incorporates missing data mechanism uncertainty. Imputations are generated from a distribution of imputation models rather than a single model, with the distribution reflecting subjective notions of missing data mechanism uncertainty. Parameter estimates and standard errors are obtained using rules for nested multiple imputation. Using simulation, we investigate the impact of missing data mechanism uncertainty on post-imputation inferences and show that incorporating this uncertainty can increase the coverage of parameter estimates. We apply our method to a longitudinal smoking cessation trial where nonignorably missing data were a concern. Our method provides a simple approach for formalizing subjective notions regarding nonresponse and can be implemented using existing imputation software.

Evaluating the training of Filipino American community health advisors to disseminate colorectal cancer screening

Community health advisor-led interventions are associated with improved health promotion behaviors, such as cancer screening, but the process of training community health advisors is rarely described and evaluated. We trained 91 Filipino Americans from 19 organizations to conduct small-group sessions with members of their organizations to promote colorectal cancer screening. Community health advisors completed brief pre- and post-training surveys that included knowledge of colorectal cancer screening guidelines (four items), perceived self-efficacy of performing specific tasks (15-item scale, Cronbach's alpha > 0.90) and satisfaction with the training itself (five items). Community health advisors had high levels of knowledge and self-efficacy at pre-training, but levels increased significantly immediately after the 6-h training (percent of knowledge items answered correctly: 63-94 %; self-efficacy: 8.2-8.9 on a 10 point scale, both p < 0.001). Correlates of self-efficacy at pre- and post-test were high educational attainment, health care background, high level of participation in the organization, being perceived by others as a leader, and frequent participation in research activities in the past. Consistent evaluation measuring similar constructs across studies may help to standardize the quality of the training, and may improve the implementation of community health advisor-led programs.

Comparison of methods for estimating the intraclass correlation coefficient for binary responses in cancer prevention cluster randomized trials

The intraclass correlation coefficient (ICC) is a fundamental parameter of interest in cluster randomized trials as it can greatly affect statistical power. We compare common methods of estimating the ICC in cluster randomized trials with binary outcomes, with a specific focus on their application to community-based cancer prevention trials with primary outcome of self-reported cancer screening. Using three real data sets from cancer screening intervention trials with different numbers and types of clusters and cluster sizes, we obtained point estimates and 95% confidence intervals for the ICC using five methods: the analysis of variance estimator, the Fleiss-Cuzick estimator, the Pearson estimator, an estimator based on generalized estimating equations and an estimator from a random intercept logistic regression model. We compared estimates of the ICC for the overall sample and by study condition. Our results show that ICC estimates from different methods can be quite different, although confidence intervals generally overlap. The ICC varied substantially by study condition in two studies, suggesting that the common practice of assuming a common ICC across all clusters in the trial is questionable. A simulation study confirmed pitfalls of erroneously assuming a common ICC. Investigators should consider using sample size and analysis methods that allow the ICC to vary by study condition.