Cohort Studies

Why take part in cohort studies?

People take part in cohort studies for a number of reasons. These types of studies often involve a long-term commitment, even if the actual time involved to fill in a questionnaire every year, attend a check-up or have a medical test is reasonably short. In our interviews, people talked about several reasons for deciding to take part or continue taking part in studies. The main reasons they had taken part were:
  • To benefit personally by finding out more about their own health.
  • To progress medical knowledge and practice.
  • To help society and future generations. 
Some people had a strong sense of why they wanted to take part, whilst others took part because they saw no reason why they shouldn’t. Lucy was enrolled in a study as a baby and continued to take part as she got older: “I just accepted that it was a thing I did and that was alright… It wasn’t that much of an inconvenience”.
 
Some people, like Emily and Keith, were taking part in more than one cohort study. Brian had been so impressed by the outputs, like research papers, from a cohort study he has been part of since birth that he decided to join another medical study.

Malcolm is motivated to take part in a ten year cardiovascular study to benefit his personal health and to benefit society in general.

Malcolm is motivated to take part in a ten year cardiovascular study to benefit his personal health and to benefit society in general.

Age at interview: 75
Sex: Male
Age at diagnosis: 48
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Oh well, well really for my own benefit to reassure me that my heart is still sound. Although, although I have a lot of hospitalisation and a lot of visits to the hospitals, it’s mostly joints and it’s mostly it’s mostly physical things rather than, you know sort of joints rather than hearts or vascular tests, so I’m always pleased to have, to know that I’m ticking along okay. And I had, I’ve had recent high blood pressure problems so I’m taking medication for that now so I’m more concerned I suppose as I get older of my own health and my own deteriorating health if it is deteriorating because I want to know about that. But it’s also a bit of altruism, I’m also interested in helping teams like you and teams like medics and doing research to give my views and use myself and samples or whatever as good practice for them to do help them research.

Okay, so it’s to...

It’s both, it’s for my own benefit and for the benefit of society in general.

Barbara hopes the birth cohort study she is in will help future generations, and it also gives her a “sort of MOT” of her health.

Barbara hopes the birth cohort study she is in will help future generations, and it also gives her a “sort of MOT” of her health.

Age at interview: 73
Sex: Female
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Well I think it’s very, I think it’s important and I think it’s important epidemiology I think is the word. It’s really all the work that they’re doing on different medical conditions, I mean it’s not going to help me and my generation but it will help future generations, you know, what they can learn from us is going to be useful for the next generations, you know, for, for next generations to come. So, but also, on the other hand, these rather in-depth medical studies, particularly this one that they’re maybe going to do on- with MRI scans, they make it very clear that if we want to they will, this information will be shared with our GP. So there is a bit of a selfish sort of element that, you know, that, you know you’re getting, you know, a full sort of MOT which will be, you know, sort of transferred to the doctor which will be sent to ones GP.

Margaret Ann has been taking part in a birth cohort study for decades. She is happy to keep contributing to the study.

Margaret Ann has been taking part in a birth cohort study for decades. She is happy to keep contributing to the study.

Age at interview: 65
Sex: Female
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Now what I would like is to the motivation from you; why do you keep participating in the study after thirty years or so?

Oh, it’s a long, long time. As I say, I think our lifestyle in the ‘50s was, you just can’t compare it to now because my life from the ‘50s is totally different and the changes over the years, my grandchildren would never understand. So, if someone, somewhere down the line thinks this is interesting, well I’m quite happy to answer the questions.

 
As researcher Jenny explains below, taking part in a cohort study is unlikely to have a direct impact on the health of the individual. However, people described to us many other kinds of benefits which they felt were important.

Jenny, a senior researcher, says that there is unlikely to be direct benefit to participants in cohort studies.

Jenny, a senior researcher, says that there is unlikely to be direct benefit to participants in cohort studies.

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I would say that their participation is really valuable however they need to be aware that there will be a time commitment from their perspective and they’re unlikely to benefit directly in many cases. They have to attend study visits which, which means they’re having a lot of tests done so their, their doctor or nurse may pick something up that they wouldn’t otherwise have picked up so they may feel that there’s, there’s extra care going on but overall the cohorts study is to change, you know, our understanding for people in the future rather than the people who are participating.

 
For personal benefit 
 
One reason why people we talked to took part in cohort studies was to find out more about their health. Alan Y was curious to find out why he had a transient ischaemic attack (TIA – a ‘mini stroke’) when he had an active and healthy lifestyle. Gareth, who took part as a healthy volunteer, explained, “I always record when I exercise, record my weight and anything that gives me some more information to go on would be interesting”. Malcolm had high blood pressure and wanted to know how his heart valves were working. Isobel, who contributed to an asthma study for about eight years, said, “It made me more confident about my own asthma”.

Nadera had a DEXA scan as part of a cohort study. She was curious to find out what was happening inside her body.

Nadera had a DEXA scan as part of a cohort study. She was curious to find out what was happening inside her body.

Age at interview: 39
Sex: Female
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I understood why they did the DEXA scan to see the subcutaneous fat, visceral fat, so I was happy to go along because it’s interesting for me to know as well what’s happening inside of me.

But that way I felt happy it was really straight forward that they could check my blood test; they could check my blood pressure; they could check my weight; they could check my fat inside me and the bone density, so actually was a good thing for me, yeah.

 
Some cohort studies involve regular health checks. People in these studies often valued the opportunity to have these check-ups and tests as they age, so they could keep an eye on their physical health. They wanted to get a warning if something was going wrong and reassurance if all seemed well. Some described taking part in research as getting a kind of “health MOT” or “extra check-up” because it gave them some feedback on their health. Douglas, who found out he had high platelet levels while taking part in a cholesterol study, said his health checks are “very thorough” and “for that alone it’s worth going”.

Lucy has been taking part in a study for 30 years. She hopes that it might spot any health problems that are occurring.

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Lucy has been taking part in a study for 30 years. She hopes that it might spot any health problems that are occurring.

Age at interview: 30
Sex: Female
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I suppose I just assumed whatever information they were getting was helpful. And also in terms of my own personal benefit, I suppose I hoped that if they spotted something that didn’t look right, then they would tell me. And, you know, I’ve got no idea whether they actually would of or not, I assume that they would of, but it could have been written into the study that they wouldn’t kind of flag things. So, yeah, I suppose a sense of, I assume it’s useful for other people, the researchers and the aim of the project, but also helpful maybe for me as well, just getting a warning if there’s something dodgy looking.

Luke thinks that researchers sometimes frame cohort studies as ‘health MOTs’ to appeal to participants. He cautions that this type of research shouldn’t be relied on for “health monitoring”.

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Luke thinks that researchers sometimes frame cohort studies as ‘health MOTs’ to appeal to participants. He cautions that this type of research shouldn’t be relied on for “health monitoring”.

Age at interview: 35
Sex: Male
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Well part of that, and this is true of many studies, part of the consent process is that if they do find anything unusual that would then be reported to my GP. But I’ve never been in that position and so there’s a certain amount of trust and faith that that would be the case and also perhaps, you know, whether it’s- blood pressure, there’re sort of such simple clinical endpoints or things that they monitor. Yeah, I don’t turn to my participation in the study for health monitoring and I don’t think it would be wise to. Although that is one of the things that they promise to their, you know, new recruits, that they say, “We’ll provide you an MOT” which I’m not sure they should do that but that’s just one of their kind of one liners, you know, that they essentially provide a kind of supplementary sort of health monitoring service as part of the study.

I mean of course you will have full bloods, monitoring, you-, and reporting, I mean they’re interested in your weight loss or gain. They’re-, because of course it’s, the clinical visits are done at four yearly intervals they can provide some kind of, they can judge changes in your, well I don’t know what you’d call it, health indicators would be at its broadest. How meaningful those changes are is not something they’re providing an interpretation of.

 
People who had a family history of a health condition were reassured by additional regular health checks and medical tests.

Gareth has a family history of high cholesterol, so he likes to keep track of it. The study he is taking part in is one way of doing that.

Gareth has a family history of high cholesterol, so he likes to keep track of it. The study he is taking part in is one way of doing that.

Age at interview: 49
Sex: Male
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I have got a family history of high cholesterol, so I’ve always been interested in keeping an eye on my cholesterol. And my dad did die young. He died in his 50s, so- of complications of heart disease. And my two sisters both have very high cholesterol. So I’ve always been interested in my cholesterol and metabolism and that side of it, and just keeping track of it. I’ve never had any problems with it. It’s always been mid to low range. So it was just a, as I say, it’s one of these things I like to measure, and if you don’t measure it, you don’t know when it’s changed, you know.

 
People who had been diagnosed with a medical condition felt there were personal benefits of taking part in long-term medical studies. Being able to talk to the research team over the course of the study about their health concerns or to get advice about new symptoms was one advantage. After having a stroke, George attended a group associated with a research group and he found it helpful learning more about how to manage his health. Another was having access to a team of specialists who were at the forefront of their field and knew the latest information and treatments. John, who had been part of a study on transient ischaemic attack (TIA – ‘mini stroke’) for ten years explained, “It was a privilege to be associated with such an extraordinary department and part of a group of people who were interested in the whole condition”.

When Alan Y had new symptoms that he wondered might be related to a transient ischaemic attack (TIA), it was reassuring to know he could talk to the research team who had access to his medical files and could advise him.

When Alan Y had new symptoms that he wondered might be related to a transient ischaemic attack (TIA), it was reassuring to know he could talk to the research team who had access to his medical files and could advise him.

Age at interview: 68
Sex: Male
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It was, I’ve had regular check-ups with them, so and regular contact with them over the years. But it was last year, I had a cataract removed off of this eye and I didn’t get back the vision that they thought I would get back, so further investigation. ‘Was it a TIA in the back of the eye or was it something else?’ And they were able to eliminate the TIA part of it, so it was something to do with the optic nerve. So that was really interesting to be part, still be part of that.

And how do you feel the fact that you have a number, a contact that if you, kind of that you can call?

Oh, I think it’s reassuring and it’s reassuring because I know they can get on the computer or open the draw and my file is there and they can go, “Oh yes, yes, you had that”.

Okay.

And they will call me back in as they did with this eye thing. “Come in, have the test”.

Okay and they provide advice over the phone?

Yeah, yeah, advice and the advice is normally, “Come in and we’ll see you”. So, it’s always, it’s always there. I know I can go in. It will get seen. They’ll do all the tests. They looked at my eye and did a scan and, and found there wasn’t a TIA there. It was something else.

Douglas chats about his general health at the check-ups he has with the research team, which he says he would not do with his GP.

Douglas chats about his general health at the check-ups he has with the research team, which he says he would not do with his GP.

Age at interview: 70
Sex: Male
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Yes, it, the good thing about it is the fact that you’re being regularly checked and they do say, ‘Oh,” because I thought I’d gained weight but they said, “you’ve actually lost weight the last time we saw you”. So that was all very positive and they do get onto me for being heavier when I was really heavier and that came down and it’s still got to come down further. So it’s quite good being, having tabs kept on you because you don’t like to, the doctors are busy enough and you wouldn’t go and see your GP for a chat and just a general health thing. While if you’re on the study, the- you can have a chat to them about it more generally, so there’s beneficial. I would say that would be the main benefit if it’s a health-related study, then you can have a chat about general things, about general health things that you could say, “Would this possibly affect the study?” because you can discuss it then and because you’re seeing them because I’m seen regularly. You know, it’ll be, it’s usually every three or four months. Either it’s a telephone call just to find out I’m fine and all the rest of it and how are things going etc, etc because they’re concerned over my general health and what’s happened to that.

 
Some people, like Gareth and Linda, talked about their curiosity and interest in research as being a motivating factor. Gareth described taking part in medical research as “part of a hobby”. Anthony described himself as “a sucker for these research things”. Those who had been in a birth cohort for many decades often found it interesting reflecting back on life in the past and what it was like compared to now. As Jennifer said, “I think everyone would be interested in a study that start in the ‘50s… I’m fascinated by history”. Being part of a big study made some people feel special. Luke thought that researchers in twins studies sometimes told potential participants “that we as a group of people are quite unique… For many people, that’s a highly motivating thing to be told”.
 
To progress knowledge 
 
To improve knowledge and progress medical practice or social policy was a common reason why people we spoke to took part. People thought there was great value in studying large numbers of people over a long period of time which could provide vast amounts of information and help discover patterns within the data.
 
The wish to improve medical knowledge was often mentioned by those who were in a study because they had a particular health condition. While they were aware that there was unlikely to be any direct impact on their own health, the hope was still important. As Roland said, “If a cure could be found for MND [motor neurone disease] in my lifetime, then I’d be foolish not to want to take part in research to help find this cure”.

Lucy believes cohort studies are important for collecting large amounts of data to discover patterns which will help to inform our understanding of medical issues.

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Lucy believes cohort studies are important for collecting large amounts of data to discover patterns which will help to inform our understanding of medical issues.

Age at interview: 30
Sex: Female
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Well I mean I think I do quite like taking part in research in general, and I hope and think that quite often research is about pooling together lots of experiences, you’re getting data from across a long period of time, especially in sort of childhood I suppose there’s probably a lot of data you can kind of gather that will tell you about how that will affect the person’s life chances or a group’s life chances, and how that’s going to change over time. So I think there’s a lot of point to medical research and longitudinal research where you can gather huge amounts of data and analyse it and sort of discover patterns which hopefully will help information- help understand medical issues better or develop medical treatments or practices, or isolate kind of socioeconomic or other factors that might be influential. So yeah, I suppose it’s just, yeah, I’m happy to take part in research that’s contributing to that, if it is useful.

Alan Z says medical advances are achieved through identifying patterns in research and so he wants to contribute and “carry on with the mission”.

Alan Z says medical advances are achieved through identifying patterns in research and so he wants to contribute and “carry on with the mission”.

Age at interview: 86
Sex: Male
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So, obviously they want to see participant’s sort of progress over time, measure what’s going on; whether it’s changed, whether it’s improved, got worse or whatever. I assume that’s going to be part of it because that’s screening several, several probably dozens, if not hundreds of people, in which presumably they’ll arrive at some helpful conclusion as to kidney functions and what, you know, what can be done to help those who are probably less fortunate. I assume that’s the operation or the outcome, yeah.

Well because throughout my life I’ve obviously heard or witnessed, you know, many sort of medical advances which even then there’s my own family have benefited from and obviously it’s all for the good of, say, everyone, you know, not just in the UK but throughout the world, these wonderful breakthroughs in medical technology are achieved and a lot of it’s done by, obviously lots and lots of painful long studies of humans and guinea pigs shall we say, and obviously they can see a pattern.

Like I say, I think it’s important that these studies are carried out not necessarily for my family but for people living in the UK etc. or across the world. So, yeah, I’ve got no concerns about it, so yeah, I carried on with the mission as it were.

Mr S believes to move forward and learn more about medical conditions, you need to do research.

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Mr S believes to move forward and learn more about medical conditions, you need to do research.

Age at interview: 35
Sex: Male
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Oh well, it was an honour in a sense because, you think, you feel a bit responsible then don’t you? You think ‘oh, look I’m making a difference; I’m, you know, providing information that could potentially have a positive effect on research and, you know maybe not in my lifetime but maybe in future years to come this research could help find information for other things, you see.’ So it’s very important in order to move forward, you’ve got to obviously, you have to do research and take knowledge from that and move forward and it’s been done in the past for example, so the only way to go forward is to do this, you see, so.

So… and just how things are now, compared to how they were before. We’ve got a lot of technology and research with different conditions that have cropped up especially with kids, who’ve got Asperger’s, autism and just trying to find out if there’s any links with these conditions. Wherever you can help, you know you want to obviously participate because at the end of the day it’s - we’re all one community and we find out where we can improve things. And see what’s out there and sometimes you’re looking for answers and you ask questions but you’re looking for answers and you don’t have the necessary answers at that particular time. So, it was all for a good cause and we duly participated.

 
Longitudinal medical research can also include healthy volunteers, as in the case of Gareth who took part in a study on metabolism. Gareth felt he could contribute towards a better understanding of how a healthy body works and so help people in the future.
 
People we interviewed who were babies or young children when their parents agreed for them to join a study were seldom aware of why their parents had made this decision. As adults, people often continued taking part because they felt there was great value to studying people over long periods of time which would produce a huge amount of data that could be used to inform medical and social practice. As Jade, who took part in a twins study, said, “There are just so many questions that this kind of data can answer”.
 
Margaret had been part of a birth cohort study for over 70 years: “I’m very proud of it… I think it’s important to-, if it helps in medical and social research, I think it’s important to stay with it”. Not everyone felt the same way. Isobel said people who had been signed up from birth by their parents should not be worried about stopping if they no longer felt comfortable with it.
 
Being part of research which may contribute to a change in social policy was also a reason why some people chose to keep taking part over many decades in birth cohort studies.

Steve hopes that by participating in a birth cohort study, his experiences of a turbulent childhood can be used to improve the health and social care support systems for future generations.

Steve hopes that by participating in a birth cohort study, his experiences of a turbulent childhood can be used to improve the health and social care support systems for future generations.

Age at interview: 64
Sex: Male
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I mean I’m very happy to help people and especially because I was involved in children’s homes and foster homes, you know, I’ve probably got a good background from that element that might actually help people in the future, you know. So in terms of the system I went through as a child, I’m only too aware that I wish I’d had a bit more help when I was a child so if I can give any-, say anything that might help you and your team to improve or learn something then I’m up, I’m very much up for it, you know.

Louise thinks it’s important to contribute to long-term studies which can develop understanding and knowledge of how society operates.

Louise thinks it’s important to contribute to long-term studies which can develop understanding and knowledge of how society operates.

Age at interview: 64
Sex: Female
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I would encourage them to, you know, if they’re at all interested in how people live and how society operates, I think, to be part of something that feeds into that is extremely important.

Okay and why do you think it’s important?

Because we need to know how society operates, how it works and we can only do that by studying it; by studying people; studying patterns of behaviour; studying opportunities; choice and so I think if you get the opportunity to participate in something like this, then it would be very worthwhile.

 
To help others, support the NHS and contribute to society
 
Taking part to help others was a common theme, whether it be people in their community, future generations, the NHS (National Health Service) or society in general. Barbara and Lucy described this as an “obligation”, and Nadera and Anne saw it as a “duty”. Linda felt that “we’re only on this earth for such a short time and if you can, you know, do something to give something back”. Isobel took part in an asthma study for about eight years which involved going to the hospital on her days off to test different inhalers. Although it was time intensive, she wanted to do it to help children with asthma. She explained, “It’s the only way we can learn”. Salma wanted to know more about what causes certain diseases and how they can be prevented to benefit her family and her community.

Taking part in medical research is Elaine’s way of contributing to society. She thinks it’s better than running a marathon to fundraise.

Taking part in medical research is Elaine’s way of contributing to society. She thinks it’s better than running a marathon to fundraise.

Age at interview: 49
Sex: Female
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But I think if everybody, you know, does a little bit - and it doesn’t have to be, you know, research. You know, it could be, there are lots of people do, you know, charity runs for things. But I just felt that it was something that didn’t bother me, having blood taken from me or a needle put into me, it just doesn’t bother me. So I felt quite happy to contribute that way. It’s better than running a marathon.

Nadera began participating in a cohort study when she was pregnant with her third child because she wanted to give back to her community and help future generations of mothers.

Nadera began participating in a cohort study when she was pregnant with her third child because she wanted to give back to her community and help future generations of mothers.

Age at interview: 39
Sex: Female
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So again, being a dedicated Muslim and I always believe in serving mankind. So, it was not only a selfish thing or thinking, giving back to the community as well. So, if maybe my understanding, my, because I could speak, I could understand. If some mothers can’t speak but they have the same thing happening in their houses and with their health, it’s maybe through me, through my work or my impact, I can help feedback for the person’s wellbeing as well. So if the research find out something, it will also benefit directly the, my next door neighbour, my sister in law, my daughter later on in life. So that was think as well, so really giving back into the community, the work.

Anne feels it’s important to contribute to research to make things better for society, for the “greater good”.

Anne feels it’s important to contribute to research to make things better for society, for the “greater good”.

Age at interview: 68
Sex: Female
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I feel that the more we can all do, I’m very much a socialist at heart and I feel that everybody should be trying to contribute to make things better for everybody else, for greater good, so I’m really happy to do that in any way. I really want to support studies that are sort of run for the benefit of everybody.

Derek was motivated to take part in a cohort study “for the good of all”.

Derek was motivated to take part in a cohort study “for the good of all”.

Age at interview: 68
Sex: Male
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Yeah I’m sure it’s all valuable stuff as a recent recipient of medical care I can see how important it is.

Okay, so its valuable stuff in which sense, in which ways?

Well you’re obviously looking at a group of people from, of my age group so I presume what happens to them is relevant to future treatment for people.

Okay, so it is not just for yourself.

No.

Or your family.

No.

It’s more for the-.

For the good of all.

 
Others simply wanted to give something back after having such good care from the NHS during their illness. As Gill explained, “I was happy to do it. I’d worked for years in the NHS and, actually, at one point they had saved my life and so I thought, ‘Well, this is something I can do to pay back, perhaps”.

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