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Cancer survivors are more dissatisfied with their sex lives – despite normal levels of sexual activity and function for their age
By rmjdsey, on 17 August 2016
Cancer survivorship rates are improving dramatically, with half of all people diagnosed with cancer in the UK now expected to survive for at least ten years. Although treatment of the cancer is the primary clinical goal, ensuring the best possible quality of life after treatment is important. Preservation of sexual function is a key component of quality of life, yet remains a commonly reported ‘unmet need’ by cancer survivors. However, sexual function declines with ageing and because the majority of cancers are diagnosed in the over-70s, it was previously unclear whether changes in sexual wellbeing reported by cancer survivors are a result of their disease or a natural by-product of ageing.
In a new study published today in Cancer we explored differences in sexual activity, function and concerns between cancer survivors and people who had never received a cancer diagnosis. The findings revealed that a diagnosis of cancer does not seem to affect whether or not people have sex, how often they have sex, what they do when they have sex, and (in the case of men) their sexual function. Compared with women of a similar age, women who had been diagnosed with cancer within the past five years were just as likely to be sexually active, although they were more likely to report problems with arousal. Following the five years post-diagnosis the only difference was greater dissatisfaction with their sex lives, with 18% of women with a history of cancer reporting dissatisfaction compared to 12% of cancer-free women. Male cancer survivors did not report any more sexual problems than their age-matched counterparts, but they were more dissatisfied with their sex lives (31% of men with cancer compared to 20% of men with no history of cancer).
The research involved 2982 men and 3708 women aged 50 years and older taking part in the English Longitudinal Study of Ageing (ELSA), a large population-based cohort of middle-aged and older adults living in England. Participants reported whether they had ever been diagnosed with cancer, and completed the Sexual Relationships and Activities Questionnaire, a comprehensive measure that includes questions on the frequency of sexual behaviours, problems with sexual activities and function, and concerns and worries about sexual activities, function and relationships. It is the first study to compare sexual behaviour and concerns between cancer survivors and controls from the same population-based study using a standardised measure.
The results of this study are generally encouraging in showing that older people with cancer do not experience greater problems with sexual activity or functioning than people of the same age without a history of cancer. However, with more than one in five men and one in nine women reporting that they were dissatisfied with their sex lives, it is clear that there is a need to identify interventions to enhance sexual health in ageing men and women. In the meantime, better advice on the normal changes in sexual activity and functioning that occur with ageing could help to address the mismatch between the normal sexual behaviour and lower sexual satisfaction seen in cancer survivors.
Article link:
Jackson SE, Wardle J, Steptoe A, Fisher A. Sexuality after a cancer diagnosis: a population-based study. Cancer. First published ahead of print 17 August 2016. doi:10.1002/cncr.30263
New evidence supports the use of twin studies to explore the effects of nature and nurture on human behaviours in childhood
By Moritz P Herle, on 5 August 2016
Written by Moritz Herle, Alison Fildes and Clare Llewellyn
Over the past century twin studies have been used to explore how nature and nurture influence individual differences in human characteristics (such as personality, intelligence or height). Identical twins share the same genes, while non-identical twins share about half of the same genes; but both types of twins grow up in the same family environment. This means that researchers can compare similarities between identical twins, and similarities between non-identical twins, to get an idea about how much differences between people in characteristics such as height are caused by nature (genes), and nurture (the environment).
The Health Behaviour Research Centre set up the Gemini twin cohort in 2007. Gemini is a landmark study of early life growth and behaviour which has been following 2400 British families with twins born in 2007. Gemini was established to help understand how genes (nature) and the environment (nurture) influence the development of eating behaviours, food preferences and growth in early childhood. Previous studies conducted by the Gemini team have suggested that individual differences in eating behaviours during childhood are strongly influenced by genes.
Like much research into early child development, these studies have had to rely on parents’ ratings of their children’s eating behaviour. This is because large sample sizes make it difficult to measure behaviours in a laboratory and because young children are unable to report accurately on their own characteristics. Parents of Gemini twins provided information about their children’s behaviour using a widely-used questionnaire called the Child Eating Behaviour Questionnaire (CEBQ). However, a criticism of twin studies is that parents might be biased by their beliefs about their twins’ zygosity (whether they are identical or non-identical) when rating each of their eating behaviours. For example, parents of identical twins might rate them more similarly simply because they think of them as ‘two peas in a pod’, while parents of non-identical twins might exaggerate the differences between them. Because twin studies are based on the comparison of similarity between identical and non-identical twin pairs, reliable and unbiased parental ratings are crucial.
We recently published a new study that set out to test if parents are biased by their twins’ zygosity when they rate their eating behaviours. Using the Gemini sample we compared eating behaviour ratings from parents who held a false belief about their twins’ zygosity (i.e. they believed them to be non-identical, when they were in fact identical) to those from parents who held an accurate belief. The only way to conclusively know whether a twin pair is identical is to conduct a genetic test, which compares the DNA of the two siblings. However these genetic tests are not routinely carried out and parents can sometimes be misinformed about their twins’ zygosity. A more thorough account of why these misunderstandings occur has been discussed in a previous study.
We established whether the Gemini twins were identical or non-identical using a combination of DNA testing and a questionnaire that accurately measures twin similarity. We also asked parents about whether they thought their twins’ were identical or not. Using this information we were able to identify parents who held a false belief about their twins’ zygosity, and those who were right. We found that approximately one third of parents of identical twins falsely believed them to be non-identical when they were about eight months old.
In order to test if parents’ ratings of their twins’ behaviours are biased by their beliefs about their zygosity, we compared the ratings of parents with false and accurate beliefs about their twins’ zygosity, on a range of eating behaviours during infancy and toddlerhood. If parent ratings were biased then we would expect identical twins whose parents believed them to be non-identical to be rated as less similar than identical twin pairs correctly identified by their parents as identical.
Interestingly, parents’ reports of their identical twins’ eating behaviours were the same, regardless of whether they had false or accurate beliefs about their twins’ zygosity. In other words, parents rated identical twins as more similarly than non-identical twins on all eating behaviours (in both infancy and toddlerhood), regardless of whether they believed them to be identical or non-identical. This indicates that parents of twins can be relied upon to provide unbiased reports of their young children’s eating behaviour, and that findings from twin studies can be trusted.
Article link:
Herle, M., Fildes, A., van Jaarsveld, C., Rijsdijk, F. & Llewellyn, C. H. (2016). Parental Reports of Infant and Child Eating Behaviors are not Affected by Their Beliefs About Their Twins’ Zygosity. Behavior Genetics. doi: 10.1007/s10519-016-9798-y
Family upbringing has no impact on adolescents’ food preferences
By Alison Fildes, on 11 July 2016
Written by Andrea Smith, Alison Fildes and Clare Llewellyn
Understanding the factors behind food likes and dislikes has important implications for politicians and clinicians. Our food preferences strongly influence what we chose to eat, affecting our health in the short- and long-term. Previous studies carried out by our group have shown that aspects of the shared family environment played an important role in shaping young children’s food preferences. However, the relative influences of genes and the environment on older teenagers’ preferences was previously unknown.
In a new study published this week in the American Journal of Clinical Nutrition we explored the relative importance of genetic and environmental influences on adolescents’ food preferences using a twin design. The findings revealed that the effects of family upbringing on teenagers’ food preferences seem to disappear as they start to make their own meal choices, to the point where they have no detectable impact by late adolescence. Instead the ‘unique environment’ – aspects of the environment that are not shared by both twins in a pair (e.g. experiences unique to each twin, such as having different friends) were found to effect food likes and dislikes at this age. Genes were also found to have a moderate impact on food preferences in late adolescence, in keeping with earlier findings from young children.
The research involved 2,865 twins aged 18-19 years from the Twins Early Development Study (TEDS), a large population based cohort of British twins born in 1994 to 1996. Food preferences were measured using a self-report questionnaire of 62 individual foods which were categorised into six food groups – fruits, vegetables, meat/fish, dairy, starch food and snacks. It is the first study to show how substantial influences of the shared family environment in early childhood are replaced by environmental influences unique to each individual by the time they enter young adulthood. The decreasing influence of the family environment in adolescence has also been observed for other traits, such as body weight.
The results of this study mean that efforts to improve adolescent nutrition may be best targeted at the wider environment rather than the home, with strategies focused on increasing the availability and lowering the cost of ‘healthier foods’. The substantial influence of the non-shared environment, suggests that food preferences can be successfully shifted towards more healthy choices in late adolescence. Policies that make the healthier food choice, the easier choice for everyone, have potential to achieve substantial public health improvements. In particular, the UK sugar-sweetened beverage levy soon to be introduced is one initiative that has the potential to promote a healthy food and drink environment.
Article link:
Smith AD, Fildes A, Cooke L, Herle M, Shakeshaft N, Plomin R, and Llewellyn C. Genetic and environmental influences on food preferences in adolescence. American Journal of Clinical Nutrition. First published ahead of print July 6, 2016. doi:10.3945/ajcn.116.133983
http://ajcn.nutrition.org/content/early/2016/07/05/ajcn.116.133983.full.pdf+html
Measuring appetitive traits in adults. What do we know about their relationships to weight.
By rmjlhun, on 6 July 2016
By Claudia Hunot, Alison Fildes and Rebecca Beeken.
Some people are more likely to put on weight than others, and may find it harder to lose weight. One of the ways in which people differ is in how they respond to food; their ‘appetitive traits’. For example, how full you tend to feel after a meal, how much you want to eat when you see or smell delicious foods, or how fast you eat. These traits are partly influenced by genes, and they explain individual differences in the way we all eat. In the present-day food-filled environment people who are more responsive to food cues (want to eat when they see or smell delicious food), and less sensitive to satiety (take longer to feel full) are more susceptible to over-eat and gain weight.
For a number of years, appetitive traits have been measured in children using the ‘Child Eating Behaviour Questionnaire’ (CEBQ) and more recently in infancy using the ‘Baby Eating Behaviour Questionnaire’ (BEBQ). These questionnaires measure a number of appetitive traits that can be grouped into two broad categories: food approach and food avoidance traits. Food approach traits, such as ‘food responsiveness’, are associated with a larger appetite or greater interest in food, while food avoidance traits such as ‘satiety responsiveness’ are associated with a smaller appetite and/or a lower interest in food. Research has shown higher scores on food approach traits and lower scores on food avoidance traits are associated with increased weight and weight gain. However, so far most of this research has been carried out in children. Until now no matched questionnaire existed for measuring the same appetitive traits in adults.
Therefore, in our latest study we developed the ‘Adult Eating Behaviour Questionnaire’ (AEBQ) to measure these appetitive traits in adults. We also wanted to explore whether these traits relate to adult weight, as they do in children. Adult samples were recruited at two time points, one-year apart, from an on-line survey panel. Participants completed the AEBQ and provided their weight and height measurements to calculate BMI. Data from a total of 1662 adults was analysed and showed the 35 item AEBQ to be a reliable questionnaire measuring 8 appetitive traits similar to the CEBQ.
We also showed that food approach traits such as ‘food responsiveness’, ‘emotional over-eating’ and ‘enjoyment of food’ were positively associated with BMI. This means people with higher scores for these traits were heavier on average. While food avoidance traits including ‘satiety responsiveness’, ‘emotional under-eating’ and ‘slowness in eating’ were negatively associated with BMI. This means people with higher scores for these traits were lighter on average.
These findings suggest appetitive traits are likely to be important for weight across the life course. The newly developed AEBQ is a reliable instrument, which together with the BEBQ and the CEBQ, could be used to track weight-related appetitive traits from infancy into adulthood. The AEBQ may also help to identify individuals at risk of weight gain and could inform targeted interventions tailored to help people manage their appetitive traits, and in turn control their weight.
Article link:
Hunot, C., Fildes, A., Croker, H., Llewellyn, C. H., Wardle, J., & Beeken, R. J. (2016). Appetitive traits and relationships with BMI in adults: Development of the Adult Eating Behaviour Questionnaire. Appetite. http://dx.doi.org/10.1016/j.appet.2016.05.024
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Updating the General Nutrition Knowledge Questionnaire for adults
By rmjlkli, on 17 June 2016
By Nathalie Kliemann, Fiona Johnson and Helen Croker
Access to nutrition information is widespread and many people rely on sources such as newspapers, websites, magazines, and TV programmes. Some of the information is conflicting and misleading, and the sheer quantity can be overwhelming, leaving many people confused as to what is the current nutrition advice. In an attempt to understand how well UK adults understand nutrition information, in the 1990’s researchers at the Health Behaviour Research Centre developed a questionnaire to assess general nutrition knowledge (GNKQ) in the UK adult population. This measure has been widely used since then and is cited in over than 150 research papers, which have explored the relationship between nutrition knowledge and other factors, such as dietary intake, socio-economic status, and use of food labels. It has also been adapted for use in different populations and translated into other languages, including Turkish, Romanian, and Portuguese.
Why update it?
Since the GNKQ was developed 20 years ago, there have been developments in our understanding of the links between diet and health, and big changes in the food supply including the introduction of new types of foods and processing methods. This has resulted in new advice regarding good nutrition, and the GNKQ needed updating to reflect the way we eat today and bring it into line with current recommendations. Our recent publication reported the development of a revised GNKQ, with four main sections measuring: knowledge of dietary recommendations; food groups; healthy food choices, and links between diet and ill health. We also conducted 4 studies to test how well the questionnaire measures nutrition knowledge in adults (tests of reliability and validity).
Main results
Our findings showed that the revised version of the GNKQ is a consistent, reliable and valid measure of nutrition knowledge, and that scores improve when people undertake nutrition training. It also showed some differences between people, as the GNKQ-R scores were higher among women, people with a degree, those with better health status and in younger adults. The sections can be administered individually to measure specific areas of nutrition knowledge. We concluded that the revised version of the GNKQ will be a useful tool to assess nutrition knowledge among the UK adult population, and identify groups of people who might benefit from nutrition education to navigate their way through the mass of nutrition information available.
Article link:
Kliemann N, Wardle J, Johnson F & Croker H. Reliability and validity of a revised version of the General Nutrition Knowledge Questionnaire. European Journal of Clinical Nutrition, 2016, 1-7.
www.nature.com/ejcn/journal/vaop/ncurrent/pdf/ejcn201687a.pdf
A new jab to prevent cancer
By rmjdafo, on 26 May 2016
What is HPV and how is it linked to cancer?
Around 5% of all cancers worldwide are caused by the human papillomavirus (“papi-lo-ma-virus”) or HPV. More and more people are aware that HPV causes cancer of the cervix (the neck of the womb) in women, but HPV can also cause cancers of the penis, anus, vagina, vulva and mouth and throat. The virus is spread by skin to skin contact, including sexual contact. There are many different types of HPV. Some types cause cancer, while others cause warts that people get on their hands, feet or genitals and these types do not cause cancer. The types of HPV that cause cancer are so common that HPV is the most frequent sexually transmitted infection in the UK. In most people the cancer causing types of HPV cause no problems and the virus goes away on its own. However, some people do not get rid of the infection. If the infection stays for many years it can turn into cancer.
HPV vaccines
In the late 1990s and early 2000s two vaccines were developed that protect against the two types of HPV that cause around 80% of cervical cancers. Girls who are aged 12-13 years old in Year 8 at school are now offered one of these vaccines as part of the childhood immunisation programme. The vaccine that is used as part of the UK programme also protects against two types of HPV that cause genital warts. Recently, a third HPV vaccine called the nonavalent or 9-valent vaccine has been licenced for use in the UK, as well as in the USA and elsewhere in Europe.
The new 9-valent vaccine
The 9-valent vaccine, as the name suggests, protects against 9 types of HPV – that means protection against an extra 5 HPV types compared with the other two vaccines. These 9 HPV types cause up to 90% of cervical cancers, so an additional 10 in every 100 cervical cancers could be prevented.
Where does behavioural science fit in?
The invention of these vaccines is a fantastic step forward towards wiping out cervical cancer, but this can only happen if people get the vaccine and we know that many people are not doing so for a variety of reasons. The benefits of the HPV vaccine will be greatest if most people get the vaccine, however as with all healthcare decisions, the decision to get the HPV vaccine should be an individual informed choice. In our new paper, we look at how we can use our understanding of why people don’t get vaccines, specifically the HPV vaccine, to try to increase uptake of the 9-valent vaccine.
Reason 1: Will the 9-valent vaccine overload the immune system?
Some parents worry that vaccines overload the immune system and others worry that particular ingredients make vaccines risky for their children. Parents consider combination vaccines to be risky for both of these reasons as they are seen as containing a greater number of ingredients. The 9-valent vaccine is not a combination vaccine, but it protects against 9 types of HPV compared to 2 or 4 types of HPV with older HPV vaccines and might be seen as more dangerous. However, parents should be reassured that the 9-valent vaccine is safe and has been licensed for use in the UK, USA and the rest of Europe. There is also no evidence that vaccines overload the immune system.
Reason 2: ‘I’ll wait to decide until there’s more evidence that it will protect my daughter in her twenties’
Many parents have said that rather than giving their 12 or 13 year old daughter the vaccine (as recommended) they would rather wait until their daughter became sexually active so that she may be protected when she ‘really needs it’. However, the HPV vaccine is likely to give protection against HPV for decades and works better if it is given at a younger age. Parents may also find it difficult to get the vaccine for their daughter outside of the routine immunisation programme. Parents should be reassured that 12 to 13 is the right age for their daughter to get the 9-valent vaccine.
Reason 3: ‘It’s so new, the government can’t know about the long-term side effects’
Because the vaccine is relatively new, some parents say that they are worried that the vaccine has not been monitored for long enough. However, vaccines go through many years of testing before they become available to the public. There is no evidence that the HPV vaccines are unsafe or cause side-effects other than temporary mild/moderate pain, swelling, redness and itching.
What else can be done to increase uptake of the 9-valent vaccine?
Scientists have looked at all of the published research studies that have tried to improve uptake of HPV vaccines. These show that uptake can be improved by doing things like sending reminders to parents and running school-based immunisation programmes like we have in the UK. In the USA, where the vaccine is given in a clinic setting, parents are most likely to get their daughter vaccinated if a doctor recommends that she has it. The language that the doctor uses to make that recommendation is also important.
The 9-valent HPV vaccine is a fantastic opportunity to prevent even more cancers that are caused by HPV. Parents can be reassured that the HPV vaccines are safe and will provide protection for their children against a number of cancers for many many years.
Could a leaflet help catch cancer earlier?
By Jo Waller, on 4 May 2016
We’ve written here before about the difficulty of recognising symptoms that could be signs of cancer, and knowing when it’s appropriate to go to the doctor about them. There’s lots of evidence that cancer is more treatable if it’s found at an earlier stage, but we know less about effective ways of encouraging people to seek help appropriately.
Encouraging people to seek help
Our new study tried to do just this. We focused on gynaecological cancers – that is ovarian, cervical, endometrial (womb/uterine), vaginal and vulval cancers which together affect over 20,000 women a year in the UK. We know from previous research that some of the things that stop people going to the doctor with symptoms are:
1) Not knowing that the symptom could be a sign of something serious
2) Worry about wasting the doctor’s time
3) Embarrassment about discussing or exposing intimate parts of the body
4) Worry about what the doctor might find
So we designed an information leaflet that addressed some of these issues. It provided details about possible symptoms of gynaecological cancer and a checklist to help women record their symptoms and make a plan to visit their GP. It reassured women that their doctor would be happy to see them, and that the symptoms were unlikely to be serious. It addressed the issue of embarrassment and reminded women they could ask to see a female doctor.
In this study 
, we u
sed questionnaires to measure the impact of the leaflet in the short-term. We asked 464 women about their symptom knowledge, the things that might put them off going to the doctor if they had gynaecological symptoms, and how quickly they thought they would seek help for a range of symptoms. We also asked about how anxious they were feeling right now, so we could see if the leaflet raised anxiety levels. Women then spent some time reading the leaflet before filling in another questionnaire.
What did we find?
After reading the leaflet, most women said they would seek help more quickly if they noticed one of the symptoms. In particular, we reduced the number of women who said they would never seek help for vague symptoms like bloating and feeling full quickly, which can be signs of ovarian cancer. Women reported fewer barriers to visiting their GP, and greater knowledge about possible symptoms of gynaecological cancer. There was no evidence that the leaflet made women feel anxious.
What next?
These findings are very encouraging, and suggest that a leaflet may be an effective way of promoting prompt help-seeking for these symptoms. But it’s also important to remember that it was an experimental study – women read the leaflet under controlled conditions, so it doesn’t tell us what impact the leaflet would have in a real-world setting where women might be sent it in the post, or handed it at their GP surgery. Under these circumstances, they might not even read it.
In addition, we could only measure women’s anticipated help-seeking, and we can’t be sure what they would really do if they had these symptoms. Even when people intend to seek help, life often gets in the way, other things take priority, and people don’t get round to making an appointment.
The next step will be to see what happens when we actually send the leaflet to women – will more of them seek help and, ultimately, will more cancers be diagnosed at an earlier stage when treatment is more effective? We hope to answer these questions in our future work.
Putting screening non-attendance under the microscope – understanding why some women don’t go for smear tests
By Jo Waller, on 26 April 2016
Authors: Amanda Chorley and Jo Waller
If you are a woman aged 25 or over, there is a good chance you have attended cervical screening (the smear or Pap test) at least once. In England last year, just under three quarters of women were ‘up to date’ with cervical screening [1], meaning that over a quarter of women are not up to date. As cervical screening, in addition to HPV vaccination, is one of the best ways to protect yourself from cervical cancer it is important to understand why some women do not attend.
Many studies have asked women about their feelings towards and experiences of cervical screening. We carried out a review of studies [2] from the UK, Australia, Sweden and South Korea – countries where women are automatically invited for screening on a regular basis.
By pulling together findings from across 39 studies, we identified two main themes. Firstly women considered whether they should go for screening – were they at risk of cervical cancer? How serious was the outcome? And is screening a useful way of dealing with that threat? Secondly, women who had previously been for screening recounted their experiences, and how this made them feel about going again.
Should I go for screening?
In deciding whether they should go for cervical screening or not, women considered whether they were at risk of cervical cancer, and therefore if screening was relevant to them. Their decisions were often based on ideas of the causes of cervical cancer, such as number of sexual partners. Women also considered their current life stage (both biological such as menopause, and social such as being the mother of young children), and their family history of cervical (and other) cancer.
Women differed in whether they thought cervical screening was worthwhile. Some talked about the benefits of early detection of cancer (e.g. better survival or ‘peace of mind’). Others believed that they would know if they had an illness as serious as cancer, without screening, or were cynical about the motives of screening programmes. The final group were aware of screening, but were unsure of its importance. These women were often from more deprived backgrounds, or were from ethnic minority groups.
Screening is a big deal
It was clear from women’s accounts that one bad experience of screening could make them avoid screening in the future. However it is important to remember that it is possible that women who have had bad experiences are perhaps more likely to take part in studies about screening than women who do not view screening as a big deal.
Some women found the prospect of screening threatening, either through the risk of being given a diagnosis of cervical cancer, the belief that you might get an infection from unclean instruments, or through the anxiety screening and the wait for results could cause. Some women reported a different kind of threat. It was believed that a positive result could mark you as “promiscuous”, and for some women (especially those from ethnic minority groups) simply attending screening could suggest to other people that you were sexually active.
Cervical screening was also seen as a big deal because of physical aspects, such as pain, or disliking the speculum. For others emotional aspects were more important. In particular, some women reported feelings of embarrassment, shame, and a loss of control during screening, due to the unusual situation in which you are expected to expose your genitals to a relative stranger.
Because of this, women across studies had a strong preference for female nurse or doctor for cervical screening.
Other factors
These are not the only reasons women do not attend screening. Some women talked about how they would like to go for screening, but competing priorities, such as childcare and work, or inconvenient appointment times or clinic locations meant that they could not easily attend. Women from ethnic minority groups also reported specific problems, such as racist treatment from health professionals, and difficulty in accessing information about screening due to a lack of translated material.
What does this mean?
Our findings show that women are not all alike in their reasons for not attending screening. Some do not think screening is relevant for them and have made a conscious decision not to go. Others have had a bad experience and wish to avoid that happening again. Yet other women would like to attend screening, but life gets in the way. And of course cervical screening is not a one-off event. Women will continue to be invited over a period of decades, and factors that were important at one stage of a woman’s life may be more or less important in the future.
Knowing this allows us to develop different kinds of information and support for women depending on which factors are most important to them. We are now also able to carry out further research to try and find out whether certain factors are more likely to be considered important by certain groups of women. Our review also made it clear that the opinions of women who have never attended, or even heard of screening, have hardly been explored. We hope to interview women from these groups in the coming months, and find out more about their barriers to cervical screening.
Can the internet help the public understand ‘overdiagnosis’ in breast cancer screening?
By rmjdapg, on 20 April 2016
Authors: Alex Ghanouni, Cristina Renzi & Jo Waller
In our last blog, we talked about ‘overdiagnosis’, a concept that many people are unfamiliar with – that is, when a medical test finds an illness that would never have caused any harm during a person’s lifetime.
As a follow-up study, we were interested in how much information the UK and Australian public could find online about overdiagnosis in the specific context of breast cancer screening.
Why breast cancer screening?
We chose breast screening because it is a setting in which the issue of overdiagnosis has received a lot of attention in the UK in recent years: in 2011, Cancer Research UK and the Department of Health commissioned a review of studies with the aim of understanding how much overdiagnosis happens in breast screening.
Likewise, the NHS recently made substantial changes to the information leaflets provided to women invited for breast screening, with the aim of ensuring that they would understand that overdiagnosis was one possible outcome of being tested.
Breast screening sometimes diagnoses ‘ductal carcinoma in situ’ or ‘DCIS’, which is an abnormality that can become a symptomatic cancer over time. However, it can also be slow growing and never pose a health risk, meaning that a large proportion of overdiagnosis in breast screening is due to DCIS.
As well as finding out what kind of information people could find about overdiagnosis on health websites, we were interested in what explanations those websites provided about DCIS, and also what kinds of statistics were used to give the public a sense of how many people are affected by overdiagnosis.
We used a Google search for ‘breast cancer screening’ to find the most relevant health websites in the UK and Australia (such as NHS Choices and Cancer Australia). We examined in detail ten websites from the UK and eight from Australia.
What did we find?
Our main findings were that most UK websites included some information about overdiagnosis and also DCIS. The websites provided a range of statistics stating, for example, that every year around 4,000 women in the UK are overdiagnosed and overtreated following screening and that around 3 in 200 women screened would be overdiagnosed and overtreated (considering women aged between 50 and 70 years undergoing screening every three years).
Such information was available less often on Australian websites, although the kind of information was similar when it was present (and several websites linked to more detailed websites instead of hosting the information themselves).
Why is this important?
One reason for doing this research was that a similar study had been carried out more than ten years ago in 2000, showing that overdiagnosis and DCIS were rarely described. We thought that things might have changed in the meantime as more and more people use the internet to understand health issues.
In fact, we found that although not every piece of information on overdiagnosis and DCIS is available on every website, it is more available than it was in the past. In time, this might lead to a greater level of public awareness about the issue.
What does the UK public understand by the term ‘overdiagnosis’?
By rmjdapg, on 14 April 2016
Authors: Alex Ghanouni, Cristina Renzi & Jo Waller
In recent years, doctors and academics have become more and more interested in a problem referred to as ‘overdiagnosis’. There are several ways that overdiagnosis can be defined.
One particularly useful way is to think of it as the diagnosis of a disease that would never have caused a person symptoms or led to their death, whether or not it had been found through a medical test. In other words, even if a person had not had the test, the disease would never have caused them any harm.
Catching it early
It may not be obvious how this can happen. As an example, imagine a woman going for breast screening, which tries to find cancer at an early stage, before it starts causing symptoms.
The thinking behind this type of test is that if the disease is found early, it will be easier to treat and there is a higher chance of curing it. Most people are familiar with this idea that ‘catching it early’ is a good thing.
So, suppose a woman who has no symptoms goes for screening and the test finds cancer: she would usually go on to have treatment (e.g. surgery).
However, although she has no way of knowing for sure, it is possible that the cancer was growing so slowly that she would have lived into old age and died of something unrelated, without ever knowing about the cancer, had she not gone for screening.
The cancer is real but the diagnosis does not benefit the woman at all; it results in treatment that she did not need (‘overtreatment’). In fact, if she had not had the screening test, she would have avoided all the problems that come with a cancer diagnosis and treatment.
What research has found
If you find the idea of overdiagnosis counter-intuitive, you are not alone. Several studies have tried to gauge public opinion on the issue and found that this is a fairly typical view, partly because the notion that some illnesses (like cancer) might never cause symptoms or death is one that does not receive much attention and is often at odds with our personal experiences.
Results from an Australian study in 2015 found that awareness of ‘overdiagnosis’ is low – in a study of 500 adults who were asked what they thought it meant, only four out of ten people gave a description of the term that was considered approximately correct and these descriptions were often inaccurate to varying degrees.
For example, people often thought in terms of a ‘false positive’ diagnosis (diagnosing someone with one illness when really they do not have that illness at all), or giving a person ‘too many’ diagnoses.
Is this the same in the UK?
We wanted to find out whether this was also true in the UK. We asked a group of 390 adults whether they had come across the term ‘overdiagnosis’ before and asked them to describe what they thought it meant in their own words, as part of an online survey.
We found that only a minority (three out of ten people) had encountered the term and almost no-one (10 people out of all 390) described it in a way that we thought closely resembled the concept described above.
It was not always clear how best to summarize people’s descriptions but we found that people often stated that they had no knowledge or had similar conceptions to the Australian survey such as ‘false positives’ and ‘too many’ diagnoses.
Some descriptions were somewhat closer to the concept of overdiagnosis such as an ‘overly negative or complicated’ diagnosis (e.g. where the severity of an illness is overstated) but there were also some descriptions that we found more surprising such as being overly health-conscious (e.g. worrying too much about health issues).
Room for improvement
Many people who work in public health and healthcare believe that people should be aware of the possibility of overdiagnosis, particularly since they will eventually be offered screening tests in which there is this risk.
In this respect, our findings show that there is substantial room for improvement in how we inform the public about overdiagnosis. In part, this may be due to the term itself not having an intuitive meaning, in which case other terms might be more helpful (for example the term ‘unnecessary detection’).
This could be tested in future studies. Our findings also motivated us to find out the extent to which trusted information sources (such as websites run by the NHS and leading health charities) are already providing information on overdiagnosis.
We would like to share the findings from this study in a follow-up blog post. We will be posting this here soon.
This was originally posted on the BioMed Central blog network.