‘Health Chatter’: Research Department of Behavioural Science and Health Blog
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    Are self-reports of cancer screening participation accurate?

    By Jo Waller, on 26 September 2015

    By Siu Hing Lo

    Health behaviour research often relies on surveys to collect data of people’s lifestyle and views about health. However, there is concern about the reliability of self-report measures. Common reasons for inaccurate self-report include the desire to give socially desirable answers and issues with recall. When people report their participation in cancer screening their answers are likely to be affected by both. Surveys consistently show that most people agree that screening is a good idea, so it is reasonable to assume they might be tempted to give a socially desirable answer when asked about their own behaviour.

    Previous evidence from the United States suggests that social desirability is not the (main) explanation (Vernon et al., 2012). Nevertheless, recall could still be a significant issue. The most common screening tests used in the UK require participation at two- to five-yearly intervals. This means that accurate self-report requires people to recall what they have done over a long period of time. In our latest survey study, we asked respondents permission to check their NHS screening records, so we could compare their self-reported participation in bowel cancer screening with their NHS records.

    Unfortunately only around 40% of the total survey sample agreed to this ‘record check’. People who agreed were also more likely to be more affluent and have participated in bowel cancer screening.
    On the positive side, we showed that those who consented to the record check could accurately report whether they have ever take part in bowel cancer screening. A large majority also accurately reported whether they had taken part at least twice (81%) and whether they had taken part every time they had been invited (77%).

    Interestingly, mismatches between self-report and records were due to both ‘over-reporting’ and ‘under-reporting’ of screening participation. On the one hand, one-fifth of respondents who said they had taken part every time, had in fact failed to respond to at least one invitation. On the other hand, roughly one-sixth reported having taken part once, even though – in reality – they had taken part at least twice.
    Although we could only examine the accuracy of self-reported bowel cancer screening among survey respondents who gave permission for the record check, it allowed us to explore what type of biases are likely to result from different survey questions. The biggest obstacle to accurate self-report of bowel cancer screening seemed to be recall of the number of screening tests received and completed. Survey measures which rely less on recall of each screening episode are therefore more likely to yield reliable data.

    References

    Lo, S.H., Waller, J., Vrinten, C., Wardle, J. & C. von Wagner (2015), ‘Self-reported and objectively recorded colorectal cancer screening participation’, Journal of Medical Screening, in press.

    Vernon S.W., Abotchie P.N., McQueen A., et al. (2012), ‘Is the Accuracy of Self-Reported Colorectal Cancer Screening Associated with Social Desirability?’, Cancer Epidemiology Biomarkers and Prevention, 21, 61-5.

    The new Bowel Scope Screening programme: Who is taking part?

    By Bernardette Bonello, on 21 September 2015

    In March 2013, the NHS in England introduced the Bowel Scope Screening programme. This is a one-time only screening offered to people at age 55.

    Bowel scope screening is a test (also known as flexible sigmoidoscopy or flexi-sig) done by a specially trained nurse or doctor. They use a thin flexible tube with a tiny camera on the end to look inside the large bowel. The screening looks for growths or polyps in the bowel and, if they find any, can be removed straightaway. Bowel polyps are harmless but if they are not removed, these polyps could turn into cancer. Therefore, by removing pre-cancerous polyps, the screening test helps to prevent bowel cancer. The test can also find cancer that is already developing and detecting cancer early increases the chances of successful treatment.

    A previous large study showed that screening using flexible sigmoidoscopy can prevent bowel cancer by removal of pre-cancerous polyps and significantly reduces bowel cancer deaths. This evidence led to the introduction of bowel scope screening within the NHS Bowel Cancer Screening Programme.

    The bowel scope screening programme is being rolled out in stages. Our latest study is the first to look at the participation rates within the new bowel scope screening programme for the first six screening centres.

    Getting the full public health benefits of screening depends largely on how many people take part and go to their screening appointment. In the first 14 months, these six centres invited 21,187 individuals to have bowel scope screening: 43% of those invited had the screening test. This is encouraging for a fairly new and invasive test, especially as there are currently no publicity campaigns for bowel scope screening.

    What is most worrying in our findings is that people living in poorer areas were less likely to take up the screening test (33%) than people living in more affluent areas (53%). Differences in uptake could mean that people from more deprived areas will be much less likely to benefit from this test. This might create inequalities in the number of people diagnosed with late stage bowel cancer when treatment is often more invasive and outcomes less favourable.

    Interestingly, men were more likely to go for bowel scope screening when invited than women (45% vs 42%). This is surprising as women are more likely to participate in the existing bowel cancer screening programme which uses a test done at home, called faecal occult blood test (FOBt). Women also have high rates of uptake for breast and cervical cancer screening. The uptake rate also varied between the six centres, partly because of differences in deprivation but mostly because of other service-related differences which are yet to be explored.

    Bowel cancer is common but bowel scope screening helps prevent it. Although the initial participation rate is encouraging, the differences in uptake between more deprived and more affluent areas are a concern. Bowel scope screening will be fully rolled out in England by 2018 and in light of its huge health benefits, we need to invest in strategies to increase public participation and to narrow inequalities in uptake so that everyone has the chance to benefit from this screening.

    This analysis is part of an ongoing larger study (Flexi-Quest) funded by Cancer Research UK which wants to find out what people think about bowel scope screening, and why some people may be less likely to go for screening. This first look at the data gave an indication about differences in participation rate; however, the findings show that there could be other factors important for participation. As part of Flexi-Quest, we will be conducting surveys and interviews that aim to identify ways in which we can remove barriers and reduce inequalities in bowel scope screening.

    References

    Atkin W, Edwards R, Kralj-Hans I, et al. Once-only flexible sigmoidoscopy in prevention of colorectal cancer: a multicentre randomised controlled trial. Lancet 2010;375:1625–33.

    McGregor, L.M., Bonello, B., Kerrison, R.S., Nickerson, C., Baio, G., Berkman, L., Rees, C.J., Atkin, W., Wardle, J., & von Wagner, C. Uptake of Bowel Scope (Flexible Sigmoidoscopy) Screening in the English National Programme: the first 14 months. Journal of Medical Screening 2015. DOI  10.1177/0969141315604659

    Public Health England. NHS Bowel Cancer Screening Programme: NHS bowel scope screening, http://www.cancerscreening.nhs.uk/bowel/bowel-scope-screening.html (2015, accessed 26 August 2015).

    Internet use promotes cancer preventive behaviours, but mind the ‘digital divide’

    By Lindsay C Kobayashi, on 4 November 2013

    The saturation of the Internet into daily life in many parts of the world has characterised the early part of the 21st century.  As a communication medium, the Internet has huge potential to increase health-related knowledge and behaviours among the general population to ultimately help prevent chronic diseases such as cancer.  However, the actual effectiveness of the Internet in improving cancer-preventive behaviours among older adults, who are among the most at risk for cancer, is unclear.  Importantly, there is unequal access to and use of the Internet in the population.  In the United Kingdom, women, older adults, and those with low income are less likely to use the Internet; this phenomenon is called the ‘digital divide’.  If using the Internet leads to participation in healthy behaviours and ultimately lower chances of cancer, then inequalities in access to online health information may increase inequalities in cancer outcomes.

    Our study examined whether Internet use is associated with cancer-preventive behaviours and whether a ‘digital divide’ exists. To do this we used data from 5,943 participants in the English Longitudinal Study of Ageing: a nationally-representative study of English adults aged 50 years and older.  The study participants responded to questions about Internet and email use, self-reported colorectal and breast cancer screening, physical activity, eating habits, physical and cognitive abilities, and demographics every two years from 2002 to 2011.

    We found that 41.4% of older English adults reported not using the Internet at all between 2002 and 2011, while 38.3% used the Internet intermittently and 20.3% used the Internet continuously during this time period.  Men and women who consistently used the Internet were two times more likely to participate in colorectal cancer screening than those who never used the Internet. They were also 50% more likely to take part in regular physical activity, 24% more likely to eat at least five daily servings of fruit and vegetables, and 44% less likely to be current smokers.

    In short, we found that Internet plays a positive role in promoting healthy cancer-preventive behaviours.  Our research also confirmed that a ‘digital divide’ exists: Internet use in this study was higher in younger, male, white, wealthier, and more educated adults and lower in older, female, non-white, poorer, and less well-educated adults.  Age is a particularly important factor in the ‘digital divide’, as over 40% of all adults aged 50 and up reported never using the Internet.  Providing appropriate support and opportunities for Internet access among older adults may be a key first step to improving health among the ageing population. More generally, increasing Internet access among groups with low rates of Internet usage may have substantial public health benefits.  Policymakers must understand this potential for ‘digital divides’ to influence inequalities in cancer outcomes – whether for worse, or, for better if targeted efforts are made to increase Internet access and literacy among vulnerable groups.

    References

    Office for National Statistics. Internet access quarterly update, 2013 Q1. 2013 [cited 25 October 2013]. Available from: http://www.ons.gov.uk/ons/rel/rdit2/internet-access-quarterly-update/2013-q1/stb-ia-q1-2013.html

    Viswanath K, Nagler R, Bigman-Galimore C, McCauley MP, Jung M, Ramanadhan S. The communications revolution and health inequities in the 21st century: implications for cancer control. Cancer Epidemiol Biomarkers Prev 2012;21:1701-8.

    Xavier AJ, d’Orsi E, Wardle J, Demakakos P, Smith SG, von Wagner C. Internet use and cancer-preventive behaviours in older adults: findings from a longitudinal cohort study. Cancer Epidemiol Biomarkers Prev 2013 (in press).

     

    What goes up, must come down?

    By Samuel Smith, on 8 September 2011

    Plans to complete a Bowel Cancer Screening test reduce after exposure to the nitty gritty of the test

    We all make plans to do things that are good for us, whether it is going for the Sunday morning jog, eating an extra spoonful of greens or saying no to that second (third or fourth!) drink in the pub. The problem is, when the time comes to actually doing whatever it is we’ve been promising ourselves and others to do, all those good intentions seem to disappear as quickly as they arrived.  For the runners among you that have woken only to be faced with a dark and drizzly January morning, you will know what it is that I’m talking about.

    So why is it that some people are able to overcome hurdles like the miserable weather, the unappealing sight boiled cabbage and the luring temptation of that extra glass of bubbly? Here at the HBRC we are particularly interested in attempting to answer that question by researching how the perception of time influences people’s behaviour. Some people are always looking towards the future and always want to be prepared for what is to come. Others just want to live for the moment and prefer not to think about what could be round the corner. Interestingly, this appears to be a relatively stable personality characteristic and it is linked to how we feel about behaving in certain ways.

    We have recently shown how plans to complete a bowel cancer screening test are affected by time perceptions. Completing a bowel cancer screening kit requires overcoming some pretty immediate obstacles (handling faeces being the most obvious to spring to mind). In addition, the benefits of doing the test won’t be experienced for at least one month (when you hopefully receive a reassuring all-clear letter), or worse, in several years’ time (when you have successfully lived for five years after your bowel cancer treatment). The question we wanted to answer was whether the same people that are able to get out of bed on a cold January morning ready for a 5 mile run, are better able to overcome the short term obstacles of a bowel cancer screening test. In other words, is the ability to look towards the future influencing decisions to complete a bowel cancer screening kit?

    We presented some snippets of information to over 200 volunteer middle aged adults (i.e. the group approaching screening age) and asked them after each statement to report ‘how likely it is that you would take part in the screening programme’ (see box 1 for the statements we showed people). Our findings showed how certain parts of the screening programme (e.g. completing it at home) were appreciated, and after finding this out the volunteers increased the strength of their plans. However, once participants were gradually informed about the nitty gritty of the test, people started to waiver. Motivation rapidly declined once people realised they had to collect a sample of faeces and hit a second low when they were informed that the test requires this to be done three times.

    Box 1 – Description of the test
    1. The NHS has introduced a screening test for men and women of a similar age group
    2. This test can detect colorectal cancer and pre-cancerous signs of colorectal cancer
    3. This test is self-administered in your own home
    4. This test provides a simple way for you to collect small samples of your bowel motions
    5. This test involves you collecting your stools in a plastic tub and sampling them for tiny amounts of blood
    6. This test involves smearing a sample of faeces onto the test kit using a cardboard stick
    7. The test involves sampling three separate bowel movements within 14 days
    8. Pictorial description of the test

     

     

     

     

     

     

    Perhaps most interestingly is that people that prefer to live for the moment were more put off by completing it three times and by some photos explaining how to complete the test kit. This enables us to pinpoint the exact stage at which motivation is reduced the most, allowing us to intervene and help people overcome these obstacles.  While this is an exciting finding (even if we do say so ourselves!), it doesn’t explain why those who prefer to stay in the present reduce their motivation faster than others. Is it because they were more put off by the short term obstacles that might affect their short term plans? Or were they just less able to see how beneficial it might be for them in the future? Our analysis seems to suggest that as always, it might be a bit of both. So back to work it is for us, but not before that five mile run I told you about. Anyone?

    Reference

    Von Wagner, C., Good, A., Smith, S. G., Wardle, J. (in press) Responses to procedural information about colorectal screening using Faecal Occult Blood testing: the role of consideration of future consequences. Health Expectations. DOI: 10.1111/j.1369-7625.2011.00675.x

     

    Sam (Samuel.smith@ucl.ac.uk)