Participation in faecal occult blood screening for colorectal cancer

Chemical faecal occult blood testing has been proposed as a means of screening for colorectal cancer (C.C.) in populations or in identified high-risk groups. The level of public participation is a critical factor in the effectiveness of screening programmes. This study was conducted as a methodological pretest for an intended investigation of factors influencing screening participation. Faecal occult blood screening was offered to 728 employees of a teaching hospital in Sydney, New South Wales and 41% participation was obtained. Both participants and non-participants were questioned on demographic and social background factors, on their experience of C.C. in others, and on their reasons for participating or not participating. Major reasons for participation were: a general feeling of the importance of health checks and screening tests; a belief that it is important to diagnose C.C. early; and the fact that the test was simple and easy to do. Prominent self-acknowledged reasons for non-participation were indifference, procrastination, absence of previous bowel complaints, preference for one's own doctor to do such tests and inconvenience or lack of time. Those more likely to participate were: females; those of Australian or British origin; single, separated or divorced persons; those having two or more dependents and those with personal knowledge of a C.C. patient.     

Arguments against implementing a population-based screening programme for colorectal cancer

Screening healthy people at low risk of colorectal cancer using faecal occult blood testing (FOBT) is an old method that was proven effective in reducing colorectal cancer mortality in randomised controlled trials published in 1993-1996. Screening reduced colorectal cancer mortality by 1 per 10,000 person-years and increased colonoscopy rates by 50 per 10,000 person-years. Population screening increases the annual cost of the diagnosis and treatment of colorectal cancer by at least 35%. Physicians and other well-informed citizens rarely undergo colorectal cancer screening. In prioritising health care needs, preference should be given to the needs of actual patients, rather than placing demands on healthy individuals.     

Colorectal cancer and its prevention: prevalence of beliefs,attitudes, intentions and behaviour

Abstract: There is so far only limited evidence from randomised controlled trials that screening for colorectal cancer using the faecal occult blood test produces significant mortality reductions in screened groups, but there is considerable activity and interest in the use of such screening in Australia. Beliefs, attitudes, intentions and behaviour in relation to colorectal cancer and screening were examined among participants 40 years and older (n = 1776) who took part in a representative population survey. While there were high levels of awareness of faecal occult blood test screening, most respondents had not had a test, nor did they intend to take a test in the future. Important determinants of participation in screening were a family history of colorectal cancer, a belief that bowel cancer can be cured if detected at an early stage, a perception of personal susceptibility to bowel cancer and an acceptance of the technique. Factors such as these are likely to influence the success of any future screening program in Australia.     

Adherence to colorectal cancer screening in an HMO population

This study aimed to determine factors that influence fecal occult blood test performance in colorectal cancer screening. A random sample was selected of men and women ages 50 to 74 years of age who had been mailed a fecal occult blood testing kit in a screening program in fall 1986. One year after initial test mailing, sample group members (n = 504) were surveyed by telephone. Four months later, the survey sample received a second fecal occult blood test mailing. Multivariable analysis for subjects with validated past fecal occult blood test status (n = 322) revealed the past testing was positively associated with physician encouragement of screening, age, the belief that cancer is curable, perceived test efficacy, and strong intention to do testing. It also was discovered that persons who felt that they had little control over their health were more likely to have done past testing. Preliminary analysis of prospective adherence showed that the strongest statistically significant independent predictor was past test performance. Prospective adherence among past nontesters (n = 121) was associated with expressed commitment to do fecal occult blood testing and reported presence of colorectal cancer risk factors. Analysis of adherence among past testers (n = 201) revealed that belief in colorectal cancer curability and age were significant predictors. The findings reported here indicate that factors influencing adherence among past nontesters differ from those for past testers. Overall, these results suggest that to increase participation in colorectal cancer screening, physicians and other health professionals should (a) deliver educational messages that increase awareness of risk factors for colorectal cancer and curability of the disease, and (b) elicit from potential screenees a commitment to engage in recommended preventive behaviors. It may also be well to consider "tailoring" messages for past nontesters and past testers, respectively, by emphasizing colorectal cancer risk factors and highlighting curability.     

Evaluation of a ''DIY'' test for the detection of colorectal cancer.

A new type of faecal occult blood test, EZ-Detect, has been evaluated in 404 patients presenting with symptoms suggestive of colorectal disease. The test avoids handling of stools and gives a result which patients can read themselves--factors which may increase patient compliance. In comparison with the Haemoccult test, EZ-Detect has the same sensitivity for blood in laboratory conditions. In clinical use 98% of patients expressed a preference for EZ-Detect but it detected significantly fewer patients with cancer than did Haemoccult (P = less than 0.05). In its present form, this type of test would be unsuitable for population screening for colorectal cancer even if improved compliance is achieved.     

Colorectal cancer screening with faecal occult blood testing: community intention, knowledge, beliefs and behaviour

The objective of this study was to examine the current community intention, knowledge, beliefs and behaviour regarding colorectal cancer (CRC) screening with faecal occult blood testing (FOBT). A cross sectional telephone survey of the general population was conducted in Queensland, Australia. A random sample of 1,136 residents aged 40-80 years were invited to participate in the survey with a response rate of 77.8%. 77.5% (95% confidence interval [95% CI]: 74.0 to 80.7%) of respondents reported that they would participate in CRC screening by FOBT if recommended to do so by doctors or health authorities. Screening intention was significantly associated with interest in further information concerning CRC or CRC screening (odds ratio: 6.7; 95% CI: 3.4 - 13.1), belief that CRC screening is necessary for persons without symptoms (5.0; 95% CI: 1.5 -17.1), and belief that treating bowel cancer in the early stages increases a person's chance of survival (5.1; 95% CI: 2.6 - 9.9). Knowledge of seeking medical advice (2.8; 95% CI: 0.9 - 8.7) and diarrhoea/constipation as a symptom of CRC (1.7; 95% CI: 0.9 - 3.2), self-initiated screening behaviour (1.5; 95% CI: 0.8 -2.9), and medical check a couple of times a year or more (2.4; 95% CI: 0.9 - 6.5) were also marginally significantly associated with screening intention. Community intention to screen for CRC with FOBT may have increased over recent years. Screening intention is associated with community knowledge, attitudes/beliefs and behaviour.     

Illness representations and coping following an abnormal colorectal cancer screening result

Receipt of an abnormal screening test result is likely to activate an illness representation that guides emotional, cognitive and behavioural responses. The study investigates relationships between illness representations specified by self-regulation theory, and coping responses in people receiving abnormal faecal occult blood test (FOBT) screening results during the UK colorectal cancer screening pilot. After completion of all clinical investigations and treatment, men and women diagnosed with invasive cancer (N=196), adenoma (N=208), or no neoplasia (N=293) completed measures of illness representations, coping and state anxiety. Gender, socioeconomic status and diagnosis explained significant variance in different coping strategies while illness representations contributed between 5% and 21% additional explained variance. While identity, causal attributions and emotional representations explained variance in the use of avoidance and distancing, perceived personal control was important in explaining efforts to make health behavioural changes following an abnormal result. Relatively more use of escape-avoidance coping following a first abnormal screen was significantly associated with non-participation in screening 2 years later.     

Colorectal cancer screening and quality of life

To evaluate the quality of life of patients following surgery for colorectal cancer, and to compare the quality of life between patients whose cancer was detected as a result of faecal occult blood screening with that of patients whose cancer presented symptomatically, an analysis was conducted within the context of the randomized controlled trial of colorectal cancer screening, University Hospital, Nottingham, UK. A total of 418 survivors of the trial's test and control groups and 33 randomly selected cancer patients completed quality of life questionnaires (Nottingham Health Profile and Health Measurement Questionnaire). The mode of entry to diagnosis and treatment (screening vs. non-screening) appeared to exert no major impact on post-intervention quality of life. The stage of cancer progression was not closely related to outcome life quality. A quality of life coefficient for surviving patients based on the Rosser classification was estimated to lie within the range 0.948–0.981. This figure accords well with the estimates of other studies of interventions in populations of similar age. Overall, there are no grounds for belleving that faecal occult blood screening for colorectal cancer per se significantly influences patients' post-intervention quality of life.     

Manipulating perceptions of colorectal cancer threat: implications for screening intentions and behaviors

Affecting peoples' perceptions of the health threat of colorectal cancer (CRC), that is, the probability of the cancer's occurrence multiplied by the severity of the outcomes, has not been experimentally manipulated as a means to increase CRC screening intentions and behaviors. As an exploratory pilot study to inform a larger randomized trial on CRC screening, we used a four-group pre-post longitudinal design to test whether providing information about: 1) colorectal cancer risks (no/yes) and, 2) the severity of treatment and illness consequences (no/yes) affected CRC screening intentions (i.e., fecal occult blood test/sigmoidoscopy) and behaviors at a six-month follow-up. The sample consisted of 119 men and women aged 50 and older who were off schedule for having a fecal occult blood test (FOBT). Although perceptions of CRC risks were not affected by the experimental manipulations, perceived severity increased screening intentions for FOBT and lowered felt ambivalence towards FOBT. At the six-month follow-up, 31% participants had a FOBT. Participants who received severity information were significantly more likely to report having had a FOBT. These results suggest that: 1) more attention needs to be given to developing strategies to affect perception of CRC risk, and 2) increasing the perceived severity of CRC is an important construct to increase FOBT screening.     

Guaiac versus immunochemical tests: faecal occult blood test screening for colorectal cancer in a rural community

OBJECTIVE: To describe patient participation and clinical performance in a colorectal cancer (CRC) screening program utilising faecal occult blood test (FOBT). METHODS: A community-based intervention was conducted in a small, rural community in north Queensland, 2000/01. One of two FOBT kits--guaiac (Hemoccult-II) or immunochemical (!nform)--was assigned by general practice and mailed to participants (3,358 patients aged 50-74 years listed with the local practices). RESULTS: Overall participation in FOBT screening was 36.3%. Participation was higher with the immunochemical kit than the guaiac kit (OR=1.9, 95% CI 1.6-2.2). Women were more likely to comply with testing than men (OR=1.4, 95% CI 1.2-1.7), and people in their 60s were less likely to participate than those 70-74 years (OR=0.8, 95% CI 0.6-0.9). The positivity rate was higher for the immunochemical (9.5%) than the guaiac (3.9%) test (chi2=9.2, p=0.002), with positive predictive values for cancer or adenoma of advanced pathology of 37.8% (95% CI 28.1-48.6) for !nform and 40.0% (95% CI 16.8-68.7) for Hemoccult-II. Colonoscopy follow-up was 94.8% with a medical complication rate of 2-3%. CONCLUSIONS: An immunochemical FOBT enhanced participation. Higher positivity rates for this kit did not translate into higher false-positive rates, and both test types resulted in a high yield of neoplasia. IMPLICATIONS: In addition to type of FOBT, the ultimate success of a population-based screening program for CRC using FOBT will depend on appropriate education of health professionals and the public as well as significant investment in medical infrastructure for colonoscopy follow-up.     

Colorectal cancer screening: discussions with first degree relatives

Screening by faecal occult blood test and colonoscopy is recommended for first degree relatives of people with colorectal cancer. While it is known that screening participation among relatives is low, relatives' beliefs and attitudes towards screening have not been explored at an indepth level. In this study, four focus group discussions with first degree relatives of people with colorectal cancer were held. Discussions were audio-taped, transcribed verbatim and the data were independently coded and analysed by the authors. Three main themes were identified: risk, understanding, and screening. Perceived risk was determined by family history, age and gender. Of concern, there was limited understanding of the asymptomatic nature of screening with most relatives initially 'screened' after consulting a doctor with colorectal symptoms. These findings need to be considered in screening programs.     

Cost-effectiveness analysis of fecal occult blood screening for colorectal cancer

OBJECTIVES: Clinical trials have demonstrated that fecal occult blood screening for colorectal cancer can significantly reduce mortality. However, to be deemed a priority from a public health policy perspective, any new program must prove itself to be cost-effective. The objective of this study was to assess the cost-effectiveness of screening for colorectal cancer using a fecal occult blood screening test, the Hemoccult-II, in a cohort of 100,000 asymptomatic individuals 50-74 years of age. METHODS: A decision analysis model using a Markov approach simulates the trajectory of the cohort allocated either to screening or no screening over a 20-year period through several health states. Clinical and economic data used in the model came from the Burgundy trial, French population-based studies, and Registry data. RESULTS: Modeling biennial screening versus the absence of screening over a 20-year period resulted in a 17.7 percent mortality reduction and a discounted incremental cost-effectiveness ratio of 3357 Euro per life-year gained among individuals 50-74 years of age. Sensitivity analyses performed on epidemiological and economic data showed the strong impact on the results of colonoscopy cost, of compliance to screening, and of specificity of the screening test. CONCLUSIONS: Cost-effectiveness estimates and sensitivity analyses suggest that biennial screening for colorectal cancer with fecal occult blood test could be recommended from the age of 50 until 74. Our findings support the attempts to introduce large-scale population screening programs.     

Cost-effectiveness analysis of screening by faecal occult blood testing for colorectal cancer in Australia

Abstract: The incremental costs and effects of annual faecal occult blood test screening in Australia were modelled for a hypothetical cohort of 1000 persons offered screening or not offered screening. Incremental costs and effects were estimated as the differences in direct health care costs (Australian costs) and years of life remaining between the annual-screen group and the control (no screen) group, based on the published results of the Minnesota randomised controlled trial. The cost per life year saved was $24 660. The greatest source of variability in the cost-effectiveness ratio is the effectiveness of screening. The 95 per cent confidence interval for cumulative mortality in the annual-screen group is 3.86 to 7.9 per 1000, assuming the control rate is fixed at 8.83 per 1000. With this confidence interval, the cost per life year saved ranges from $12 695 to $67 848. The cost-effectiveness ratio increases to $48 000 if no mortality benefit is assumed beyond the end of the trial follow-up period, 13 years. The results are sensitive to the cost of colonoscopy (at $400 per colonoscopy, the cost per life year saved is $12 319) and the false-positive rate. The cost-effectiveness of colorectal cancer screening is comparable with that of other screening programs but further evidence is needed on the efficacy of screening. Whether the benefits of colorectal cancer screening outweigh the harm and costs needs to be more certain before more resources are committed to mass screening. Health policy planners should initiate planning for Australian pilot projects in the event that the efficacy of screening is confirmed by two current studies.     

Increasing compliance with colorectal cancer screening: the development of effective health education

The ability of a health education leaflet to raise awareness of the frequency of colorectal cancer and its asymptomatic nature and to increase intention to participate in screening with faecal occult blood testing (FOBT) was investigated. One hundred subjects were interviewed before and after reading the leaflet. The number of men stating bowel cancer was 'very common' increased significantly from 20 to 60% (chi 2 = 16.7, P < 0.0001) and those understanding its asymptomatic nature form 64 to 92% (chi 2 = 11.4, P < 0.001). The leaflet significantly increased the percentage of women reporting bowel cancer as 'very common' from 30 to 70% (chi 2 = 16.0, P < 0.0001) and as being asymptomatic from 58 to 94% (chi 2 = 17.8, P < 0.0001). After reading the leaflet, 55% of men who initially declined screening reversed their decision (chi 2 16.5, P < 0.0001) and 50% of female non-adherers reversed their decision (chi 2 = 17.3, P < 0.0001). Reasons most frequently given for declining colorectal cancer screening were feeling well (77% of subjects declining), concern about further tests (38%), unpleasantness of FOBT (13%) and illness (6%). This leaflet successfully educates people about colorectal cancer and increased intention to participate in screening programmes.     

Participation in fecal occult blood screening: a critical review

The factors that influence participation in fecal occult blood screening for colorectal cancer are poorly understood. A better understanding of these factors could lead to better screening products or to educational approaches to increase participation with currently available products. In this article, we review findings from studies that have examined the determinants of participation in fecal occult blood screening. Two components of participation are identified: initial agreement to participate and subsequent compliance with the testing procedures. We conclude that the factors that lead to agreement often differ from those that lead to compliance. Following the literature review, we discuss ways in which recent advances in attitude and behavior research might be used to improve future investigations of the determinants of participation in fecal occult blood screening. Specifically, this research suggests that investigators should focus on beliefs and attitudes associated with the perceived consequences of screening participation rather than on other types of beliefs and attitudes; measure beliefs and attitudes at the same level of specificity as behavior; and distinguish between individuals' initial agreement to participate in screening and their actual participation.     

The potential benefits and harms of screening for colorectal cancer

Abstract: Australian guidelines for colorectal cancer screening for average-risk populations vary from recommendations for annual screening by faecal occult blood testing for those over 40 years to recommendations that screening may be appropriate if requested by an informed patient aged 50 to 75 years. There are five large screening trials, of which three have published mortality data. A meta-analysis of the mortality data suggests a 19 per cent reduction in colorectal cancer mortality (95 per cent confidence intervals 0.68 to 0.96) with Hemoccult screening. Because of the width of the confidence interval, decisions about the magnitude of the effect of screening should await further trial results, which should be available in the next few years. In the interim, we should examine issues of harm and costs in Australia. For example, in the major trials, over 80 per cent of positive results have been falsely positive and have required invasive investigation. Estimates of the cost-effectiveness of screening for the Australian health system are not yet available and are essential. If the benefits of screening outweigh the harms and costs, a successful screening program would require provision of screening infrastructure and appropriate information to target populations, quality control for screening tests and investigations, recall mechanisms to ensure appropriate follow-up of persons with positive results and the active participation of the Australian public and health practitioners.     

The effect on compliance of a health education leaflet in colorectal cancer screening in general practice in central England.

OBJECTIVE: To raise compliance in a general practice based colorectal cancer screening programme by the use of a simple health educational leaflet. DESIGN: A randomised controlled trial of the leaflet's effect on completion of faecal occult blood tests. The leaflet explained the high frequency of colorectal cancer, the principles of screening, and addressed reasons for non-compliance. SETTING: The British town of Market Harborough where most of the population are registered with a single practice. PARTICIPANTS: These comprised 1571 residents aged 61 to 70 years registered with the practice. Residents were invited to receive a free faecal occult blood test in a colorectal cancer screening programme. Half the population were randomly assigned to receive the educational leaflet about screening. RESULTS: Compliance in test and control groups, positive rate of stool testing, and pathology detected were measured. Compliance was higher in men who received the leaflet in those aged 61 to 65 years (36% v 27%, chi2 = 4.0, p < 0.05) and in men aged 66 to 70 years (39% v 23%, chi2 = 9.7, p < 0.01). In women, use of the leaflet did not affect compliance in those aged either 61 to 65 years (38% v 36%, chi2 = 0.1, NS) or 66 to 70 years (31% v 31%, chi2 = 0.0, NS). The positive rate of stool testing in patients observing the required dietary restrictions was 1.6%. A significant lesion was detected in 1.4% of people tested (2 carcinomas and 5 patients with adenomatous polyps). CONCLUSIONS: Health education leaflets addressing reasons for non-compliance significantly increased compliance in men and should be used in screening programmes. Reasons for the lack of success of the leaflet in women should be investigated and other interventions for raising compliance should be developed.     

Prevalence of appropriate colorectal cancer screening and preferences for receiving screening advice among people attending outpatient clinics

Objective: To examine among people attending outpatient clinics aged 50–74 at average risk of colorectal cancer (CRC): 1) The proportion who report: a) faecal occult blood test (FOBT) within the past two years; and b) colonoscopy within the past five years, including the reasons for undergoing colonoscopy; 2) characteristics associated with under‐screening; 3) For those who are under‐screened, the proportion who are: a) willing to receive help and the acceptability of different methods of receiving help, and; b) unwilling to receive help and reasons for this. Methods: Cross‐sectional survey of 197 participants attending a major regional hospital in New South Wales, Australia. Multivariable logistic regression was used to determine correlates of under‐screening. Results: A total of 59% reported either FOBT in the past two years or colonoscopy in the past five years. Of those reporting colonoscopy in the past five years, 21% were potentially over‐screened. Males were more likely than females to be under‐screened. Of those under‐screened (41%), fewer than half were willing to receive screening advice. Conclusions and implications for public health: A significant proportion of people attending outpatient clinics are under‐screened for CRC, with some people also over‐screened. There is a need to explore strategies to overcome both under‐ and over‐screening.     

The cost of screening for colorectal cancer.

STUDY OBJECTIVE--The aim was to make projections of the likely costs and yield resulting from the implementation of a faecal occult blood screening programme for colorectal cancer. DESIGN--Cost and clinical data were derived from the MRC colorectal screening trial currently in progress in Nottingham, UK. SETTING--The above data were used as the basis for modelling the likely implications were the trial to be reproduced as a screening programme within a "typical" family practitioner committee area. MAIN RESULTS--For an average family practitioner committee area with a target population of 75,000 subjects aged 50-74 years, the initial screening round might be expected to detect 85 cancers at a total cost of approximately 250,000 pounds. This represents a cost per cancer detected of 2700 pounds and a cost per person screened of approximately 5 pounds. For subsequent screening rounds, total costs might be expected to fall although average costs are likely to remain approximately constant. CONCLUSIONS--The model is successful in generating "order of magnitude" estimates for the costs of implementation of a screening programme for colorectal cancer. As benefit estimates are not yet available, however, no cost-effectiveness analysis can be undertaken at this stage. In general, sensitivity analyses reveal that programme costs are more sensitive to changes in clinical variables, especially detection and compliance rates, than they are to variations in the costs of resource inputs. A screening programme with a more elaborate protocol than that currently employed in the Nottingham trial will entail considerable cost increases.     

National industry's interest in colorectal cancer screening programmes.

The interest of the largest 200 British industries in developing and financing colorectal screening services for employees was determined. A standard questionnaire asked if the company would advertise screening supply names of employees to local hospitals and finance faecal occult blood testing. The reasons for rejection were noted. Eighty-six companies returned the questionnaire (43% response rate) of which 78 firms (39% of the total mailed) were prepared to advertise screening programmes at the workplace. A quarter of the companies were prepared to both advertise and release employee details. Companies willing to participate employed significantly more people (mean of 17,000 employees) than those rejecting screening (mean of 6100 employees, Mann-Whitney U test = 7, P < 0.05). Fifty-nine industries would consider financing screening, although only five made a definite decision to do so. All companies rejecting (36/36) were concerned about releasing employee information to hospitals. If screening does reduce mortality and community programmes are developed industry could and is prepared to advertise such programmes. If a partnership between hospitals and industry is developed, concerns about employee confidentiality needs to be addressed.