Health literacy and self-efficacy for participating in colorectal cancer screening: The role of information processing
Introduction
The UK National Health Service (NHS) has recently added CRC screening to its population based, organized cancer screening programs. One of the hallmarks of organized cancer screening programs is that every adult registered with the national health service and within the target age range (60–69 years of age for the CRC program) will automatically receive an invitation for screening, usually on their 60th or 61st birthday. The scale of the operation is such that the initial communication is exclusively in writing, making reading ability an essential pre-requisite for use of these services.
Health literacy is one factor that may directly influence an individual's willingness or ability to engage with necessary information about cancer screening. For example, a recent study into facilitating informed choice in the Australian colorectal screening program demonstrated the negative impact of limited health literacy when reading long, dense and complex information about cancer control and prevention [1]. Specifically, those with poorer reading skills described the density of text in the standard version of a decision aid as intimidating and frightening.
Negative attitudes towards information-seeking have also been documented in a recent analysis of the doctor–patient relationship and information giving in health care. Many patients, irrespective of their literacy levels, reported difficulties with information leaflets [2]. Some of the low health literacy respondents admitted that they found reading leaflets difficult (e.g. “I was given this leaflet and it is like ‘gobbledygook’ to me, I can’t read a word”) and also frequently stated that they lacked interest in reading leaflets (“I don’t like reading leaflets”; “I never read leaflets”; “I’m just not interested, I don’t like booklets…”).
Perhaps the most robust evidence for social and educational gradients in health information-seeking has been provided by the Health Information Trends Survey. In 2003, the first wave of this US-based, general population survey demonstrated that information-seeking was predicted by a series of demographic variables including gender, age and ethnicity. Importantly, the survey found that participants who did not have at least some college-based education were significantly less likely to classify themselves as information seekers [3].
A more recent national survey found that health information Web site users were more likely to be non-Hispanic Whites (34%) than African American (31%) or Hispanics (20%) and higher health literacy was associated with greater website use amongst Hispanics. Similarly, the survey found that none of the African American or individuals Hispanic respondents aged 65 years and older reported ever going online [4]. Finally, a recent validation study of three health literacy scales found that total health literacy scores among 138 type 2 diabetes patients in Japan were significantly associated with the number of health information sources utilized by these patients indicating that more literate patients (particularly with regards to communicative and critical literacy) used a greater number of information sources to acquire health information [5].
Evidence therefore shows that adults with limited health literacy are less likely to seek out or engage with printed health communication. Moreover, limited health literacy is not only a barrier to information-seeking; it is also problematic once information has been accessed. A study of 217 emergency department patients showed that patients with lower literacy scores had poorer comprehension of printed discharge instructions (written at an 11th grade reading level) even after controlling for education level, age, primary language and race [6]. In a study of 395 adult patients from low income community populations, Wolf and colleagues found misunderstanding of common dosage instructions was significantly more likely in patients with lower literacy compared to those with marginal or adequate health literacy (63% versus 51 and 38%) [7]. The impact of limited health literacy on comprehending written communication was also demonstrated in an innovative experimental paradigm (teach-to-goal) in which comprehension of informed consent forms was assessed using true or false statements concerning study procedure, risk and confidentiality [8]. Lower literacy was strongly associated with requiring more attempts to comprehend the information.
Limitations in health literacy have also been found to have broad implications for cancer awareness and knowledge of cancer-related health services. For example, limited health literacy has been associated with lower knowledge about, and more negative attitudes towards colorectal (CRC) screening [9], [10], [11]. One study found that participants in colon cancer focus groups did not acquire adequate understanding of the concept of screening even after it was explained several times [9] and men with lower health literacy were shown to be 3.5 times more likely not to have heard about colorectal cancer and 1.5 times more likely not to know about screening tests. Participants with limited health literacy also expressed more negative attitudes towards CRC screening using fecal occult blood testing (FOBt), including worries that FOBt may be messy and inconvenient. Men with lower health literacy skills were found to be four times more likely to refuse the offer for FOBt-based CRC screening, even if it was recommended by their physician [10]. In another study, Miller Jr. et al. interviewed 50 patients (25 of whom were below ninth level reading grade) and found that patients with limited health literacy were less able to name or describe a CRC screening test and were less knowledgeable about CRC screening than those with adequate literacy levels [12].
Overall, the evidence suggests that adults with limited health literacy are less likely to seek printed information, less able to understand it, and are generally less aware and knowledgeable about cancer screening.
While the associations between health literacy, health-related knowledge and attitudes are significant, previous studies have found that these associations only partially account for the link between health literacy and health outcomes [13].
It is therefore important to establish connections between health literacy and variables that are more proximal to behavior.
Self-efficacy – an individuals’ perception of their ability to perform a specified behavior/set of behaviors – represents an important construct in this context [14]. It has been used extensively to predict the likelihood of enacting behaviors in various contexts [13] including CRC screening [15], [16], [17]. For example, Myers et al. found that self-efficacy among Caucasian male employees was significantly related to screening intentions, independent of perceived susceptibility and benefits [15]. In another workplace study of employees aged 40 and older, self-efficacy was a significant and independent predictor of colonoscopy attendance [17].
Health literacy has also been identified as a predictor of self-efficacy in the context of diabetes and HIV-self care [5], [13] Wolf and colleagues found that in a consecutive sample of 204 HIV infected patients, limited health literacy was associated with reporting lower self-efficacy for taking their medications as prescribed [13]. More recently, Ishikawa et al., in their study of 138 diabetes outpatients, found a significant association between health literacy scores and self-efficacy for diabetes self-care [5].
This study aimed to document the association between health literacy and willingness/ability to seek information about CRC screening, as well as self-efficacy for CRC screening. Fig. 1 presents an outline of key concepts and how these were operationalized for the present investigation. To begin, with we have highlighted each of the connections considered as part of this study. From this it should become clear that we restricted ourselves to studying associations between health literacy and each of the outcome measures, while omitting possible pathways between information-seeking, comprehension and self-efficacy.
In order to examine information-seeking, we presented participants with an interactive information menu and monitored the number of information links opened at least once. On the basis of the available evidence, we predicted that low health literacy would be associated with reduced information-seeking behavior (i.e. participants opening fewer links from the interactive menu).
We also tried to elucidate the association between health literacy and information-seeking by monitoring the effort associated with reading. We operationalized effort as the amount of time taken to switch from one information link to the next. We assumed that the longer time spent on an information link demonstrated greater the effort. On the basis of evidence demonstrating associations between health literacy and reading difficulties, we predicted that participants with lower health literacy would have to invest greater effort in reading information about CRC screening.
We also studied comprehension of information about CRC screening by presenting a set of forced-choice knowledge questions once participants had proceeded from the information menu. We predicted that lower health literacy would be associated with less knowledge about why and how to participate in colorectal screening.
Finally, we constructed a scale of self-efficacy to engage in CRC screening. The scale included items regarding perceived ability to complete the initial test and perceived likelihood to accept an offer of additional testing in response to an abnormal FOBt result.
We predicted that participants with lower health literacy would have lower self-efficacy. However, we also predicted that this association would be attenuated when controlling for information-seeking, processing effort and comprehension.
Section snippets
Sample
Ethical approval was obtained from the University College London Research Ethics Committee and recruitment took place from March to July 2008. We invited 144 members aged between 50 and 69 years from the Health Behaviour Research Centre Participant Panel and received responses from 86 participants (60%). The panel consists of adults who have previously participated in studies or population surveys organized by the centre and agreed to leave their personal details to be informed about future
Sample characteristics
Table 1 provides an overview of the descriptive statistics for the sample of participants and the key outcome measures. The mean age of participants was 59.8 years (SD = 4.3 years), almost 20% were from non-white ethnic backgrounds, and 33.3% were male. Approximately, two-thirds (67%) of the sample had a university degree, while 39% were unemployed.
Health literacy, information-seeking, reading effort, comprehension and self-efficacy
Table 1 presents descriptive statistics for each of the outcome measures in this study. The mean TOFHLA score was 92.19 (SD = 9.79, range = 26–100).
Discussion
This study used an interactive information-seeking exercise to substantiate previous research demonstrating the barriers of limited health literacy when engaging with health information. We used the example of the CRC screening program because of its heavy reliance on written information. Specifically, we demonstrated that lower health literacy was associated with a significantly greater burden when trying to process complex medical information in a printed format.
This is consistent with
Conflict of interest
None declared.
Acknowledgements
We would like to thank Dr. Dennis Wright and Mark Stewart at the London Bowel Cancer Screening Hub for their support with this research.
Role of funding: This study was supported by Cancer Research UK.
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- 1
In the UK the National Health Service (NHS) officially refers to this program as “NHS Bowel Cancer Screening Programme.”