The effect of information about false negative and false positive rates on people's attitudes towards colorectal cancer screening using faecal occult blood testing (FOBt)

How Synthesis Tasks Are Affected by Probability Format: A Making Numbers Meaningful Systematic Review

Background. To develop guidance on the effect of data presentation format on communication of health probabilities, the Making Numbers Meaningful project undertook a systematic review. Purpose. This article, one in a series, covers evidence about a "synthesis task," in which readers examine stimuli to synthesize information about multiple features of health options, such as chances of both harm and benefit for a treatment. This article presents evidence of the effect of format on perceptual, cognitive, affective, and behavioral outcomes. Data Sources. MEDLINE, Embase, CINAHL, the Cochrane Library, PsycINFO, ERIC, ACM Digital Library; hand search of 4 journals. Finding Selection. Manual pairwise screening to identify experimental and quasi-experimental research comparing 2 or more formats for presenting quantitative health information to lay audiences. This article reports on 91 findings derived from 45 unique studies reported in 42 articles. Data Extraction. Pairwise extraction of information on stimulus (data in a data presentation format), cognitive task, and perceptual, affective, cognitive, or behavioral outcomes. Data Synthesis. Evidence was found about 6 outcomes: identification/recall, contrast, effectiveness perceptions/feelings, behavioral intentions/behavior, trust, and preference. No strong evidence was found. Moderate evidence suggests that for synthesis tasks, behavioral intention is not affected by whether the risk and benefit probabilities are in text or in tables, that people prefer tables to text for presenting this information, and that effectiveness feelings are not affected by whether or not numbers are supplemented by narratives. Limitations. Granular data extraction and evidence syntheses lead to narrow evidence statements. Conclusions. Current evidence on synthesis tasks is moderate strength at best. Future studies should enrich the evidence on how to present information needed to synthesize multiple features of health options, given the importance of this task.

Highlights

This study found a moderate number of studies assessing strategies for evaluating sets of probabilities conveying information such as risks and benefits.Evidence is moderate that although presenting sets of probabilities in table versus sentences may not affect behavioral intentions, people may prefer tables.Contrary to previous studies about probability feelings, moderate evidence suggested that narratives may not affect effectiveness feelings.Evidence was insufficient to draw conclusions regarding contrast, identification, and trust outcomes, and no studies assessed recall, categorization, computation, or discrimination outcomes.

Scope, Methods, and Overview Findings for the Making Numbers Meaningful Evidence Review of Communicating Probabilities in Health: A Systematic Review

Background. The format in which probabilities are presented influences comprehension and interpretation. Purpose. To develop comprehensive evidence-based guidance about how to communicate probabilities in health and to identify strengths and weaknesses in the literature. This article presents methods for the review of probability communication and is accompanied by several results articles. Data Sources. MEDLINE, Embase, CINAHL, the Cochrane Library, PsycINFO, ERIC, ACM Digital Library; hand search of 4 journals. Study Selection. Two reviewers conducted screening to identify experimental and quasi-experimental research that compared 2 or more formats for presenting quantitative health information to patients or lay audiences. Data Extraction. In our conceptual framework, people make sense of a stimulus (data in a data presentation format) by performing cognitive tasks, resulting in perceptual, affective, cognitive, or behavioral responses measured as 1 of 14 distinct outcomes. The study team developed custom instruments to extract concepts, conduct risk-of-bias evaluation, and evaluate individual findings for credibility. Data Synthesis. Findings were grouped into tables by task and outcome for evidence synthesis. Limitations. Reviewer error could have led to missing relevant studies despite having 2 independent reviewers screening each article. The granular data extraction and syntheses slowed the work and may have made it less replicable. Credibility was evaluated by only 2 experts. Conclusions. After reviewing 26,793 titles and abstracts, we identified 316 articles about probability communication. Data extraction produced 1,119 individual findings, which were grouped into 37 evidence tables, each containing evidence on up to 10 data presentation format comparisons. The Making Numbers Meaningful project required novel methods for classifying and synthesizing research, which reveal patterns of strength and weakness in the probability communication literature.

Highlights

The Making Numbers Meaningful project conducted a comprehensive systematic review of experimental and quasi-experimental research that compared 2 or more formats for presenting quantitative health information to patients or other lay audiences. The current article focuses on probability information.Based on a conceptual taxonomy, we reviewed studies based on the cognitive tasks required of participants, assessing 14 distinct possible outcomes.Our review identified 316 articles involving probability communications that generated 1,119 distinct research findings, each of which was reviewed by multiple experts for credibility.The overall pattern of findings highlights which probability communication questions have been well researched and which have not. For example, there has been far more research on communicating single probabilities than on communicating more complex information such as trends over time, and there has been a large amount of research on the effect of communication approaches on behavioral intentions but relatively little on behaviors.

A qualitative interview study on colorectal cancer screening in China

Background

The effectiveness of triage screening for colorectal cancer (CRC) is not fully achieved in Chinese populations, mainly due to low compliance to colonoscopy follow-up. This study aimed to collect viewpoints of experts in China on ongoing screening programs and emerging screening tests for CRC, which may help to improve effectiveness of CRC screening in the country.

Methods

We conducted 15 semi-structured interviews with experts involving CRC screening in China during October to November of 2020. Interview topics included personal characteristics, work context, opinions on ongoing screening programs, challenges and opportunities in optimization of screening strategies, and prospects for CRC screening in near future. To analyze the data, we used a generic qualitative research approach inspired by grounded theory, including open, axial, and selective coding.

Results

This analysis revealed a total of 83 initial categories, 37 subcategories and 10 main categories, which included 4 core categories of current modality for CRC screening, factors influencing screening effectiveness, optimization of CRC screening modality, and prospects for development of CRC screening. The results provide insight into the factors underlying the challenges of the ongoing CRC screening programs in China: the most important concern is the low compliance to colonoscopy, followed by the low specificity of the currently-used initial tests. The experts proposed to use quantitative instead of qualitative fecal immunochemical test (FIT), and optimize risk assessment tools to improve specificity of initial tests. Regarding the emerging screening tests, 9 of 15 experts did not think that the novel techniques are good enough to replace the current tests, but can be used complementarily in opportunistic screening for CRC.

Conclusion

The viewpoints of Chinese experts suggested that use quantitative FIT or optimize risk assessment tools may help to identify high-risk individuals of CRC more accurately, improve adherence to colonoscopy, and thus fully achieve the effectiveness of screening.

The effect of numeric information about the likelihood of receiving a false negative or false positive result on people's attitudes towards colorectal cancer screening using faecal immunochemical testing (FIT)

OBJECTIVE

To examine the impact of numeric risk information about false negative (FN) and false positive (FP) rates in fecal immunochemical testing (FIT) on attitudes towards screening.

METHODS

102 people aged 45-55, living in the UK, read 6 hypothetical vignettes presented online about the use of FIT kits to detect colorectal cancer, in which information about FN and FP rates was systematically varied.

RESULTS

Numeric FN risk information reduced people's interest in screening, perception of screening effectiveness and lowered trust in screening compared to verbal FN information. Verbal FN information reduced perceptions of screening effectiveness and trust compared to no FN information. People with high subjective numeracy reported lower trust in screening following the provision of numeric FN information but numeracy did not moderate any other associations. FP information did not affect attitudes towards FIT testing.

CONCLUSION

Numeric FN risk information decreased people's perceptions of screening effectiveness and trust in the results of screening. While it influenced people's interest in screening, the effect was small.

PRACTICE IMPLICATIONS

Numeric FN information has a small effect on interest in screening and could promote informed decision making without affecting screening uptake.

Perceived Importance of the Benefits and Harms of Colorectal Cancer Screening: A Best-Worst Scaling Study

OBJECTIVES

To elicit the relative importance of the benefits and harms of colorectal cancer (CRC) screening among potential screening participants in the Dutch population.

METHODS

In a consensus meeting with 11 experts, risk reduction of CRC and CRC deaths (benefits) and complications from colonoscopy, stress of receiving positive fecal immunological test (FIT) results, as well as false-positive and false-negative FIT results (harms) were selected as determinant end points to consider during decision making. We conducted an online best-worst scaling survey among adults aged 55 to 75 years from the Dutch Health Care Consumer Panel of The Netherlands Institute for Health Services Research to elicit preference values for these outcomes. The preference values were estimated using conditional logit regression.

RESULTS

Of 265 participants, 234 (89%) had ever participated in CRC screening. Compared with the stress of receiving a positive FIT result, the outcome perceived most important was the risk of CRC death (odds ratio [OR] 4.5; 95% confidence interval [CI] 3.9-5.1), followed by risk of CRC (OR 4.1; 95% CI 3.6-4.7), a false-negative FIT result (OR 3.1; 95% CI 2.7-3.5), colonoscopy complications (OR 1.6; 95% CI 1.4-1.8), and a false-positive FIT result (OR 1.4; 95% CI 1.3-1.6). The magnitude of these differences in perceived importance varied according to age, educational level, ethnic background, and whether the individual had previously participated in CRC screening.

CONCLUSION

Dutch men and women eligible for FIT-based CRC screening perceive the benefits of screening to be more important than the harms.

Effects of Promotional Materials on Attitudes and Fear towards Colorectal Cancer Screening among Chinese Older Adults: An Experimental Study

Colorectal cancer (CRC) screening is a cost-effective prevention and control strategy. However, the promotion of CRC screening for older adults may be difficult because reading CRC prevention information may evoke embarrassment, fear, and anxiety towards the screening procedure and cancer diagnosis. This study aims to (1) examine the effects of three promotional materials for CRC screening on the attitudes toward CRC screening tests (screening interest, screening effectiveness, and trust in the screening results) and cancer fear, and (2) to explore the interaction effect of cancer fear with screening effectiveness and trust in the screening results on screening interest of the three screening tests (fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy) among Chinese older adults. A total of 114 community-dwelling older adults were asked to look at the corresponding promotional materials (pamphlet, cartoon, and video) of one of the three study groups. The pamphlet and video represent convention strategies and the cartoon represents an innovative strategy. No significant difference was observed in the screening interest and cancer fear across groups. FOBT was the most preferred screening modality. The video group has a large proportion agreed screening effectiveness of flexible sigmoidoscopy than pamphlet and cartoon groups and trusted in the screening results for FOBT and flexible sigmoidoscopy than the pamphlet group. Logistic regression results showed that the effect of trust in the screening results on screening interest for colonoscopy was greater among participants with higher cancer fear than those with lower cancer fear level. In conclusion, the three promotional groups had produced similar results in their attitudes toward CRC screening and cancer fear. The use of cartoons may be a comparable approach with conventional methods in the promotion of CRC screening. Additional components that can arouse fear and boost response efficacy simultaneously might also be useful for the effective promotion of colonoscopy among Chinese older adults.

Ethical issues with colorectal cancer screening-a systematic review

RATIONALE, AIMS, AND OBJECTIVES

Colorectal cancer (CRC) screening is widely recommended and implemented. However, sometimes CRC screening is not implemented despite good evidence, and some types of CRC screening are implemented despite lack of evidence. The objective of this article is to expose and elucidate relevant ethical issues in the literature on CRC screening that are important for open and transparent deliberation on CRC screening.

METHODS

An axiological question-based method is used for exposing and elucidating ethical issues relevant in HTA. A literature search in MEDLINE, Embase, PsycINFO, PubMed Bioethics subset, ISI Web of Knowledge, Bioethics Literature Database (BELIT), Ethics in Medicine (ETHMED), SIBIL Base dati di bioetica, LEWI Bibliographic Database on Ethics in the Sciences and Humanities, and EUROETHICS identified 870 references of which 114 were found relevant according to title and abstract. The content of the included papers were subject to ethical analysis to highlight the ethical issues, concerns, and arguments.

RESULTS

A wide range of important ethical issues were identified. The main benefits are reduced relative CRC mortality rate, and potentially incidence rate, but there is no evidence of reduced absolute mortality rate. Potential harms are bleeding, perforation, false test results, overdetection, overdiagnosis, overtreatment (including unnecessary removal of polyps), and (rarely) death. Other important issues are related to autonomy and informed choice equity, justice, medicalization, and expanding disease.

CONCLUSION

A series of important ethical issues have been identified and need to be addressed in open and transparent deliberation on CRC screening.

Testing innovative strategies to reduce the social gradient in the uptake of bowel cancer screening: a programme of four qualitatively enhanced randomised controlled trials

Background

Bowel cancer screening reduces cancer-specific mortality. There is a socioeconomic gradient in the uptake of the English NHS Bowel Cancer Screening Programme (BCSP), which may lead to inequalities in cancer outcomes.

Objective

To reduce socioeconomic inequalities in uptake of the NHS BCSP’s guaiac faecal occult blood test (gFOBt) without compromising uptake in any socioeconomic group.

Design

Workstream 1 explored psychosocial determinants of non-uptake of gFOBt in focus groups and interviews. Workstream 2 developed and tested four theoretically based interventions: (1) ‘gist’ information, (2) a ‘narrative’ leaflet, (3) ‘general practice endorsement’ (GPE) and (4) an ‘enhanced reminder’ (ER). Workstream 3 comprised four national cluster randomised controlled trials (RCTs) of the cost-effectiveness of each intervention.

Methods

Interventions were co-designed with user panels, user tested using interviews and focus groups, and piloted with postal questionnaires. RCTs compared ‘usual care’ (existing NHS BCSP invitations) with usual care plus each intervention. The four trials tested: (1) ‘gist’ leaflet (n = 163,525), (2) ‘narrative’ leaflet (n = 150,417), (3) GPE on the invitation letter (n = 265,434) and (4) ER (n = 168,480). Randomisation was based on day of mailing of the screening invitation. The Index of Multiple Deprivation (IMD) score associated with each individual’s home address was used as the marker of socioeconomic circumstances (SECs). Change in the socioeconomic gradient in uptake (interaction between treatment group and IMD quintile) was the primary outcome. Screening uptake was defined as the return of a gFOBt kit within 18 weeks of the invitation that led to a ‘definitive’ test result of either ‘normal’ (i.e. no further investigation required) or ‘abnormal’ (i.e. requiring referral for further testing). Difference in overall uptake was the secondary outcome.

Results

The gist and narrative trials showed no effect on the SECs gradient or overall uptake (57.6% and 56.7%, respectively, compared with 57.3% and 58.5%, respectively, for usual care; allp-values > 0.05). GPE showed no effect on the gradient (p = 0.5) but increased overall uptake [58.2% vs. 57.5% in usual care, odds ratio (OR) = 1.07, 95% confidence interval (CI) 1.04 to 1.10;p < 0.0001]. ER showed a significant interaction with SECs (p = 0.005), with a stronger effect in the most deprived IMD quintile (14.1% vs. 13.3% in usual care, OR = 1.11, 95% CI 1.04 to 1.20;p = 0.003) than the least deprived (34.7% vs. 34.9% in usual care OR = 1.00, 95% CI 0.94 to 1.06;p = 0.98), and higher overall uptake (25.8% vs. 25.1% in usual care, OR = 1.07, 95% CI 1.03 to 1.11;p = 0.001). All interventions were inexpensive to provide.

Limitations

In line with NHS policy, the gist and narrative leaflets supplemented rather than replaced existing NHS BCSP information. This may have undermined their effect.

Conclusions

Enhanced reminder reduced the gradient and modestly increased overall uptake, whereas GPE increased overall uptake but did not reduce the gradient. Therefore, given their effectiveness and very low cost, the findings suggest that implementation of both by the NHS BCSP would be beneficial. The gist and narrative results highlight the challenge of achieving equitable delivery of the screening offer when all communication is written; the format is universal and informed decision-making mandates extensive medical information.

Future work

Socioculturally tailored research to promote communication about screening with family and friends should be developed and evaluated.

Trial registration

Current Controlled Trials ISRCTN74121020.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 5, No. 8. See the NIHR Journals Library website for further project information.

Ethical issues in colorectal cancer screening

In many countries, colorectal cancer screening is currently an established population screening program due to the evidence on its reduction of colorectal cancer mortality. There is general consensus that colorectal cancer screening meets the screening criteria as proposed by Wilson and Jungner. However, as for all population screening programs, colorectal cancer screening also has disadvantages and thereby entails ethical issues. There are the general issues concerning the introduction of screening programs (e.g. medicalization, overdiagnosis and overtreatment, information provision to screenees), evaluation of cancer screening programs (e.g. lead time and length bias), chosen screening method (e.g. false-positive and false-negative test results, reduction of all-cause mortality, choice between different screening methods). The different colorectal cancer screening methods and the ethical issues concerning colorectal cancer screening will be discussed in this review.