Elsevier

Preventive Medicine

Volume 36, Issue 5, May 2003, Pages 525-535
Preventive Medicine

Regular article
Knowledge, attitudes, and behavioral intentions in relation to the early detection of colorectal cancer in the United Kingdom

https://doi.org/10.1016/S0091-7435(03)00016-1Get rights and content

Abstract

Background

Colorectal cancer (CRC) mortality is high. Understanding the social, psychological, and cognitive predictors of early detection practices such as screening may help improve CRC outcomes. This study examined knowledge of CRC and the relationship between knowledge, attitudes to cancer, and intentions to engage in early detection behaviors for CRC in a national representative population sample.

Method

An interview-based survey was carried out in a British population sample of adults ages 16 to 74 years (n = 1637), assessing knowledge, attitudes, and intention with regard to colorectal cancer.

Results

Knowledge levels were very low; 58% (n = 995) of respondents could not list any colorectal cancer risk factors and 24% (n = 393) were unable to identify any warning signs for cancer. Knowledge was lower among men (χ2[2] = 52.8, P < 0.0001), younger respondents (χ2[10] = 79.9, P < .0001), and those with less education (χ2[4] = 73.9, P < 0.0001). Attitudes to cancer were more negative among women (χ2 [2] = 7.4, P = 0.025), younger participants (χ2[10] = 22.4, P = 0.013), and those with less education (χ2 [4] = 75.0, P < 0.0001). Low knowledge was associated with negative attitudes (P < 0.0001) and both factors were associated with lower intentions to participate in colorectal cancer screening (P < 0.0001). Multivariate analysis indicated that attitudes partially mediated the effect of knowledge on screening intentions.

Conclusion

Increasing knowledge may reduce negative public perceptions of cancer which may impact positively on intentions to participate in screening.

Introduction

Cancer is a disease that provokes enormous public anxiety and elicits cognitions and emotions about its cause, consequence, and cure [1], [2]. It is a major cause of mortality throughout the Western world and accounts for around 25% of all deaths in the United Kingdom annually [3], [4], [5], with similar proportions across Europe [6] and the United States [7]. Colorectal cancer (CRC) accounts for a substantial proportion of the cancer burden in Western countries and is the second leading cause of cancer death in the United Kingdom [8] and the United States [7]. One of the principal ways to reduce deaths from cancer is to ensure that people seek medical help for suspicious symptoms, and that they use screening programs where they are available.

Screening techniques for CRC have been widely available in the United States for some time, yet are considerably underutilized [9], and delays in seeking health advice following bowel symptoms are also often reported [10], [11]. Understanding the social, psychological, and cognitive predictors of early detection practices for colorectal cancer may be one way to improve CRC outcomes.

Health psychologists have developed a number of theoretical models to elucidate and characterize the determinants of screening participation and help-seeking behavior. Such models have contributed to our understanding of health behavior and our ability to intervene to change behavior. Although the details of the theoretical models vary, all of them identify attitudes as important predictors of health behavior [12], [13], [14], [15], whether they are operationalized as costs and benefits (Stages of Change [16]), benefits and barriers (Health Belief Model (HBM) [12]), or behavioral beliefs and outcome evaluations (Theory of Reasoned Action/Planned Behavior [13], [14]).

Among these models, the Theory of Reasoned Action (TRA), extended into the Theory of Planned Behavior (TPB) [14], has had arguably the most consistent support in predicting and explaining health behavior [17], [18]. The TPB posits that the most proximal determinant of a person’s behavior is behavioral intention, assuming that the behavior is under an individual’s volitional control. Much attention has been given to the relationship between intention and behavior. Despite variation across different behaviors, intention has been found to be reliably—albeit moderately—correlated with many health behaviors behaviors [17], [18], including attendance at CRC screening [19].

Behavioral intention is conceived as a function of three sets of factors; attitudes toward the behavior, subjective norm (the perceived social pressure to perform the behavior), and perceived behavioral control (the amount of control the individual believes they have over the behavior). Attitudes have been repeatedly shown to be a reliable predictor of intentions and behavior in this and other theoretical models of behavior [17], [18], [20].

A substantial body of research has examined the way in which attitudes vary, and how they relate to behavior (see [15] for a review), but less attention has been paid to the factors that influence attitudes themselves in the context of health behavior. Attitudes toward cancer, and specifically CRC, have been shown to vary by socioeconomic position, with negative, pessimistic, and fearful attitudes overrepresented in lower socioeconomic and less educated groups [21], [22], [23]. In the TPB, sociodemographic factors are conceived as distal predictors, exerting their effect via attitudes and the other core components of the model; however, there has been little attention given to their specific role within the model, and how they might impact on more proximal predictors of intention and behavior.

One way in which sociodemographic factors may influence attitudes toward a health threat, such as cancer, is through knowledge. Existing evidence suggests that people have only a hazy understanding of the causes or prevention of cancer including CRC [24], [25], [26], [27], [28]. Importantly, there appears to be a consistent socioeconomic gradient in knowledge, with those who are most socioeconomically deprived demonstrating the lowest levels of knowledge and understanding [24], [25], [26], [29], [30].

Although an overemphasis on knowledge at the expense of other social and psychological processes has been criticized, knowledge is an important prerequisite for instigating behavior change [24], [31], [32], and it is likely that knowledge of CRC will inform attitudes toward CRC screening and other early detection behaviors. The movement toward more informed decision-making in cancer screening has also led to a greater emphasis on individuals’ knowledge and understanding of cancer risk and disease outcomes, and the way in which these impact on decisions to participate [33], [34].

In the absence of any studies of the relationship between knowledge of and attitudes to cancer, it has not been established whether better knowledge would be associated with more positive or more negative attitudes toward the disease. If existing public understanding is optimistic, then increasing knowledge could lead to a more pessimistic view, to more negative thoughts about cancer, and even to avoidance of early detection behaviors. Alternatively, if current views are unduly pessimistic, particularly in some groups (e.g., low socioeconomic groups), a more realistic understanding of the disease could result in more positive attitudes and greater willingness to participate in cancer prevention behaviors. One small U.K. study examined the interaction between knowledge, cognitions about cancer, and help-seeking behavior. It assessed knowledge of cancer warning signs and help-seeking behavior, using quantitative methods, among patients registered in an urban GP practice, and examined patients’ beliefs about cancer using qualitative interviews [35]. The study indicated that better knowledge was linked with help-seeking behavior; however, the correlation was weak, and the authors suggested that the gap between knowledge and behavior might be accounted for by individuals’ beliefs about cancer.

Further investigation of the relationship between cancer knowledge, attitudes, and health behavior is needed. The aim of this study was to examine public knowledge of CRC and investigate associations between knowledge, attitudes, and intentions to practice early detection behaviors in relation to CRC in a large representative U.K. population sample, using the TPB as a broad theoretical framework. Since attitudes to cancer may often be general, rather than specific to certain types of cancer [21], [36], we hypothesized that they may be informed by general knowledge about cancer as well as knowledge specific to CRC. As such we included general measures of cancer knowledge and attitudes, in addition to measures specific to CRC.

Section snippets

Participants

Interviews were carried out with a stratified probability sample of men and women in Great Britain as part of the January 2000 Omnibus survey for the Office of National Statistics. From a target sample of 2747 adults aged 16 and over, 1830 (67%) were interviewed in their homes; 689 (25%) of the target sample refused to take part in the interview and the remaining 228 (8%) could not be contacted (three attempts were made per person). Respondents of age 75 and over (n = 190) were excluded from

Results

A total of 1637 adults between the ages of 16 and 74 responded to the survey. The sociodemographic characteristics of the study sample are set out in Table 1.

Discussion

This is the first study linking knowledge and attitudes with intentions to carry out early detection behaviors in relation to CRC in a national population sample. The results indicated that knowledge was poor among all respondents and was even lower than that reported in similar British samples [26], [28]. One explanation for this may be the different methodologies used in the research. The two earlier studies [26], [28] both used a list of answers for participants to select from to measure

Acknowledgements

Support from Cancer Research UK (formerly the Imperial Cancer Research Fund) is gratefully acknowledged.

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