Effect of Health Belief Model on the Participation in Fobt Crc Screening Programme: Case/Control Study


 BackgroundColorectal cancer is the second cancer-related cause of death in the world. Tumor stage at diagnosis is the principal prognosis factor of survival. However, the participation in the program is around 50%. The aim of the study was to identify the benefits and barriers perceived by the population when participating in a colorectal cancer screening program with faecal occult blood test.MethodsWe carried out a cases-controls study with 408 participants. We analyzed epidemiological and social variables associated with lifestyle and behavioral factors based in the Health Belief Model. We conducted a descriptive analysis, and identified variables associated to adherence by a logistic regression. ResultsVariables independently associated with the participation in a colorectal cancer screening program were age (OR 1.06; 95% CI: 1.01-1.11), having a stable partner (OR 1.96; 95% CI: 1.20-3.18), the level of education (OR 1.59; 95% CI:1.02-2.47) and two of the barriers to participate in the faecal occult blood test screening: “not to know how to do it” (OR=0.46; 95% CI: 0.23-0.93) and “to take the test is currently not a major problem” (OR=0.43; 95% CI: 0.24-0.78).Conclusion The existing barriers for screening with faecal occult blood test are the best factor predicting. This is relevant when designing the intervention programs, as they should focus on reducing perceived barriers to increase the participation in colorectal cancer screening, thereby reducing colorectal cancer mortality.


Abstract Background
Colorectal cancer is the second cancer-related cause of death in the world. Tumor stage at diagnosis is the principal prognosis factor of survival. However, the participation in the program is around 50%. The aim of the study was to identify the bene ts and barriers perceived by the population when participating in a colorectal cancer screening program with faecal occult blood test.

Methods
We carried out a cases-controls study with 408 participants. We analyzed epidemiological and social variables associated with lifestyle and behavioral factors based in the Health Belief Model. We conducted a descriptive analysis, and identi ed variables associated to adherence by a logistic regression.

Results
Variables independently associated with the participation in a colorectal cancer screening program were age (OR 1.06; 95% CI: 1.01-1.11), having a stable partner (OR 1.96; 95% CI: 1.20-3.18), the level of education (OR 1.59; 95% CI:1.02-2.47) and two of the barriers to participate in the faecal occult blood test screening: "not to know how to do it" (OR=0.46; 95% CI: 0.23-0.93) and "to take the test is currently not a major problem" (OR=0.43; 95% CI: 0.24-0.78).

Conclusion
The existing barriers for screening with faecal occult blood test are the best factor predicting. This is relevant when designing the intervention programs, as they should focus on reducing perceived barriers to increase the participation in colorectal cancer screening, thereby reducing colorectal cancer mortality.

Background
Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in the world, accounting 935.173 deaths in 2020. The incidence of this neoplasm, irrespective of gender, is the third highest after breast and lung cancer, with an estimated 1.931.590 new cases in 2020 (1).
Five-year relative survival rate for patients with CRC in Spain is just 57%. Survival of CRC patients detected in a screening programme is higher than that of patients diagnosed for symptoms (2). The screening strategy for medium-risk population (individuals over the age of 50 without additional risk factors) is a biennial Faecal Occult Blood Test (FOBT), sigmoidoscopy every 3-5 years or colonoscopy every 10 years (3). Although the coverage of the screening programmes is nearly universal in our country, participation in such programmes is still below 50% and most CRCs are still being diagnosed outside of the screening programmes (4). Page 3/20 There are three groups of factors associated with adherence: those related to the organization of the screening programme (5), those related to social factors (6) and those dependent on the views of the individual. For this latter factor, several theoretical models of human behaviour have been adopted in an attempt to understand the subjective elements of the individual in uencing his/her participation in preventive activities programmes. Some of these theories are the Bandura's Social Cognitive Theory, the Prochaska and DiClemente the Transtheoretical Model, Ajzen's Theory of Planned Behaviour and the Health Belief Model (HBM); the latter model is the most widespread and thoroughly assessed in the bibliography (7).
HBM was described by Rosenstock in 1966 (8). He states that decision making in healthcare is a process divided into different stages. This Model describes several cognitive concepts which predict behaviour in preventive activities: perceived susceptibility (belief about the risk of developing a health problem), perceived severity (belief about how serious a condition and its possible consequences are), perceived bene ts (belief about the effectiveness of the tests to reduce the risks), perceived barriers (beliefs about the material and psychological obstacles to performing the preventive tests) and cues to action (the stimulus needed to trigger a behaviour modi cation). In 1988 a new dimension inspired by Bandura's Theory and called self-e cacy (the person's con dence in his/her own abilities) was added to the Model.
Further on, the notion of perceiving treatment becomes relevant in the management of chronic pathologies (9)(10) (Figure 1).
Three systematic reviews (7)(11) (12) and a meta-analysis (13) support the adequacy of HBM in public health. We have HBM-based questionnaires validated for CRC screening in different populations with applications in research and clinical practice. In this respect, Jacobs adapted for colorectal cancer screening the questionnaire initially developed by Champion for breast cancer. Based on HBM cognitive concepts, Rawls validated in the United States a speci c questionnaire for every screening test: FOBT, sigmoidoscopy and colonoscopy (14). Rawl's questionnaire was validated in several countries and in different populations and it is the most common in the bibliography (15)(16)(17)(18). The limitations of HBM are caused by its sidelining of the economic and emotional factors in uencing human behavior (19).
The aim of the study was to identify the bene ts and barriers perceived by the population when participating in a CRC screening program with FOBT.

Methods
We designed a case-control study performed in three primary health centers in Valencia, Spain: Chile, Argentina and Serrería II. We performed a simple random sampling among individuals invited to participate in the colorectal cancer screening programme. Data were collected by previously trained researchers from March to September 2019. The individuals agreeing to participate in the study were scheduled for an in-person appointment on the invitation of the researchers.
We included subjects invited to participate in the CRC screening programme of the Comunitat Valenciana, to which all individuals between the ages of 50 and 69 years without symptoms and not meeting any of the permanent exclusion criteria to participate in the CRC screening programmes were invited. Permanent exclusion criteria are a personal history of CRC, in ammatory bowel disease, colorectal polyposis, colorectal adenoma, colectomized patients, individuals suffering from severe comorbidity or with a family history of familial adenomatous polyposis or other hereditary polyposis syndromes, hereditary nonpoliposis colorectal cancer, two or more rst-degree relatives with CRC or one rst-degree relative with CRC diagnosed before age 60.
Exclusion criteria for this study were: 1. Individuals that declined to participate in the study.
2. Individuals meeting any of the permanent exclusion criteria of the CRC screening programmes.
We de ned the cases are those individuals who agreed to participate in any round of the CRC screening programme of the Clínico-Malvarrosa health area in Valencia and took the FOBT test. Results of the FOBT test were registered in the colorectal cancer screening section of the Abucasis electronic medical records programme. On the other hand, we de ned controls as those individuals who did not provide the faeces sample needed to perform the FOBT after being invited via post to participate in the CRC screening programme. Consequently, their participation is not registered in the colorectal cancer screening section of the Abucasis electronic medical records programme.
Sample size was calculated on the basis of an expected prevalence of low social support of 30% (20) a con dence interval of 95% and a potency of 80%. The necessary number of individuals is 342 for an odds ratio of 2.
The variables analyzed were as follows: 1. Sociodemographic factors: a. Age: de ned as the age in years of the patient on the date of the collection of data for the study. b. Gender: male or female. c. Civil status: de ned under the Civil Register rules as single, widowed, married, separated/divorced, or unmarried couples. d. Level of education: illiterate population and population with primary education, secondary education degree / middle level vocational training or university degree / higher level vocational training were considered. e. Social class: professional quali cation of the patient on the date of the interview shall be assessed by adapting the British classi cation of social class to the Spanish reality (21) 2. Factors associated to lifestyle: a. Smoking habit: smoker -non-smoker. We de ned an active smoking habit in those individuals smoking more than one cigarette per day during the three months prior to their participation in the study were classed as smokers. b. Alcohol consumption. Measured in Basic Units per Week (BUW). c. Body mass index (BMI). Weight (in kilograms) and height (in metres) were recorded. BMI was subsequently calculated by dividing weight in kilograms by the square of the height in metres. d. Family history of CRC in rst-and second-degree relatives. Data were obtained by asking a direct question (yes/no) to the individual in the course of the clinical interview. e. other neoplasms in rst-and second-degree relatives of the patient. Data were obtained by asking a direct question (yes/no) to the individual in the course of the clinical interview. f. Personal history of non-CRC neoplasms: Yes-No. These data were obtained from the active medical records of the patient in the Abucasis computer programme. of personal data. The researchers signed a con dentiality agreement and speci c measures were also taken to maintain the integrity and security of the data and to prevent the access of third parties to any identi ed or identi able personal data. No paper or report derived from the study shall use or contain identi ed or identi able data or images.

Results
A total of 1,017 individuals were invited to participate in the study. As shown in gure 2, 358 individuals could not be contacted; 128 did not want to participate; 80 were unable to attend the interviews; and 43 did not meet the criteria for inclusion.

Discussion
Our study found that the theoretical HBM model is consistent with CRC screening in the Spanish population. The perceived barriers stated by individuals with regard to the collection of FOBT samples appear as the most powerful cognitive concept of the Model, unlike the bene ts of the screening. This has to be taken into account when planning educational interventions in the population.
Mean age of participants was around 60 years, in line with the age of similar studies, as it is the usual age range for medium-risk CRC screening (22)(23). We have found that older patients participate more in CRC screening (OR: 1.06). This coincides with other papers which also report a similar magnitude of the effect (24)(25)(26) (7). But it disagrees with other studies which do not nd a correlation with age (16)(27) (28).
We have not noted a difference between genders in our sample, as other authors have also noted (28)(16) (29). On the contrary, other studies (23)(7) note that women participate less than men in CRC screening. A recent systematic review (6) (Mosquera 2020) in which the majority of studies were carried out in Western countries concluded that women participate more in the collection of FOBT samples and less in colonoscopy with regard to men; all these gender differences can be related to the conditions of gender equality in each country.
The percentage of married people (72.10%) in our study is similar to that of other papers (14) (15). Married patients in our study had increased participation in the CRC screening (OR 2.13). This connection is also found in the majority of published papers and is consistent with people who have greater social support (30)(31)(27)(28). There are, however, other series that do not nd this connection to the civil status (26) (32).
Population in our sample is of urban middle / upper class extraction, partly comparable with that in a Turkish study by Ozsoy (15) . Contrary to what might be expected, we also found that patients participating in the screening do not perceive more bene ts. This association is also found by Rawl in the initial validation of the questionnaire (14) and by Leung in the Hong Kong study, where it is also noted that those not participating in the screening perceive more barriers and fears, but there were no differences in the bene ts (16). Kivinienmi's systematic review (7) does not nd a relationship with bene ts perceived after the CRC screening in 13 out of 35 analyzed studies of faecal occult blood tests.
One of the renowned authors of the HBM points out that a possible explanation for this fact is that Bene ts would be more predictive to promote healthy lifestyles (non-smoking) than other preventive activities (10). Other authors have suggested as an explanation that people reduce their perception of severity after participating in the screening. All this would explain the apparent paradox of people with personal or family history of cancer not signi cantly increasing their participation in CRC screening programmes, as noted in our results and by other authors (31)(27) (32). However, other series do nd a relationship between between a history of cancer and CRC screening (26) (29). HBM indicates that decision making in health and lifestyle is a process in different phases in uenced by the social norm and group to which the individual belongs. Longitudinal surveys must be designed in order to clarify this negative association opposite to the direction of the HBM theoretical model.
Our results clearly re ect that the BARRIERS raised by the individual to take a FOBT are the factor best predicting participation in CRC screening programmes. This is consistent with the HBM postulates which state that perceiving barriers is the most powerful dimension of the Model (25) (43). We also have to take into account the untraceable population in our study as it could introduce a bias for losses, although we did not nd any differences with regard to age and gender when that population was included.
The educational interventions that proved to be most effective to increase the participation in CRC screening are focused on promoting personalized health advice, removing barriers, improving accessibility to the test (which includes providing tests outside working hours), community interventions based on health workers and dissemination of information by the media (44)(45)(32)(46). To this regard, our results support the implementation of interventions aimed at eliminating barriers and improving the accessibility of FOBT.

Conclusions
As a conclusion, we can say that the existing barriers for screening with FOBT are the factor best predicting participation in CRC screening programs. This is signi cant when designing the intervention programs, as they should focus on reducing perceived barriers and improving accessibility to the test to increase the participation in CRC screening, thereby reducing CRC mortality. Longitudinal studies in different populations are necessary to make further progress in the understanding of human behavior in preventive activities and select the most effective intervention measures. Competing interests: The authors declare that they have no competing interests.
Availability of data and material: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.