research design advice for clinical research

posted
29-Sep-15, 11:43
edited about 16 seconds later
Avatar for beetsforblood
posted about 5 years ago
Hi everyone,

I'm starting a PhD and i'm doing a little background reading before I begin next month. I'm currently looking at research design and methodology and i'm debating between the use of a control group for my study.

The study essentially looks at whether a nutritional supplement will lower the risk of CVD within a selected clinical population. Of course, this population will continue with the course of treatment prescribed to them by their Drs, so in order to determine whether the supplement lowered the risk of CVD (not their usual course of treatment), I could use a control group who would receive a placebo, whilst the exp. group received the treatment. It would control for bias too.

I'm not used to clinical research so i'm not sure about the ethics of using a control group, I was wondering if anyone had any advice? or could prehaps suggest another design. Sorry I appear ignorant. I've always wanted to do a PhD and am starting after a few years working outside of research.

Cheers guys.
posted
29-Sep-15, 13:47
edited about 1 hour later
Avatar for janjansen
posted about 5 years ago
Hi there! I am also doing a clinical study. I believe its always better to have an intervention and control group. But thats not always possible. For example, in my study it is not ethical to give patients a placebo, since this will have tremendous impact on their health status. Has there be done research on this topic before? And is it a phase I, II or III study?
I think you should contact the ethical committee to get detailed information on this.
posted
29-Sep-15, 14:35
edited about 1 second later
Avatar for DocInsanity
posted about 5 years ago
Why would a control group be unethical?
posted
29-Sep-15, 14:49
edited about 3 seconds later
by Eds
Avatar for Eds
posted about 5 years ago
Not my field at all, but would it be because it would mislead people into thinking they're reciving a form of treatment when they're actually not?
posted
29-Sep-15, 15:06
edited about 1 minute later
Avatar for janjansen
posted about 5 years ago
@DocInsanity, I think you are right, it should not be unethical. I guess I have read too fast and didnt clearly get your research objective.
Anyway I think that a randomized controlled trial is better than a prospective cohort study.
Let me know if you need any more information, I just handed in my research proposal for a clinical trial :)

@Eds, people are supposed to sign an informed consent letter before the onset of the study, explaining that they will be allocated to either a treatment arm (in this case a supplement) or a control arm (in this case a placebo). Therefore patients will be aware that they may get the placebo
posted
29-Sep-15, 15:51
by Eds
Avatar for Eds
posted about 5 years ago
Thanks janjansen ;) I'll go back to my toys ;)
posted
29-Sep-15, 20:00
edited about 10 seconds later
Avatar for DrJeckyll
posted about 5 years ago
A control group can be unethical. If you start an intervention that there is evidence that is beneficial for a group of people, then you deny these benefits from the control.

So, one way to go around this problem, is to offer to the control group an improved version of the intervention next year.
posted
30-Sep-15, 12:56
Avatar for beetsforblood
posted about 5 years ago
Thanks everyone!

@janjansen Actually, a RCT would fit perfectly. Thanks for the advice :) will ask my supervisor what he thinks. I suppose it's more of a phase 0/1 study, but i'm not using a formal drug. i'm using a beetroot drink for it's inorganic nitrate. I may have to ask you for more advice in the future if you've already done a clinical study XD

@DrJeckyll That's exactly what I was taught when I did my degree, so that's why i'm a little cautious of a control group, but you've offered a good solution. Thank you!
posted
30-Sep-15, 14:25
Avatar for chickpea
posted about 5 years ago
Just to add that if you're doing this in the UK and getting NHS ethical approval, talk to your supervisor and apply for the ethics really early. You might already know this anyway, but it can be a lengthy and complex process to get approval - good luck!
posted
30-Sep-15, 20:46
edited about 15 seconds later
Avatar for Thesisfun
posted about 5 years ago
I think you need to think carefully about what you are proposing, as this sounds well beyond what is achievable within a PhD.

The outcome of reduction in CVD will require a huge sample size and a long follow-up period.

Will you be using a surrogate outcome?

From an ethical standpoint, I am confused why there is any concern about using a control group. Providing that:
- Other management continues as per normal with the only difference being the addition of a beetroot juice or placebo, and
- There is clinical equipoise about the use of beetroot juice,
- Participants give informed consent,

Then there should be no problem.

If there is evidence to support an intervention, then there is unlikely to be clinical uncertainty so a trial is likely to be unethical.
posted
02-Oct-15, 10:45
edited about 23 seconds later
by Yve
Avatar for Yve
posted about 5 years ago
Ok, my background is pretty much entirely clinical research. I didn't do a clinical trial for my PhD (graduated this summer -yay!) but I used clinical populations. I would ask are you doing this in the UK and if so, do your supervisors or people on the team have experience of clinical research (better yet, also does some clinical work within the NHS)? If you are in the UK and no one in the team has done clinical research before and no one has good clinical links I STRONGLY advise you to not to attempt a clinical trial for your PhD.

If you are part of a team/department/unit with a good clinical research background or you have a clinical background yourself (in which case get as much help as you possibly can from your local NHS R&D department) then you'll probably be OK giving it a go.

To answer your original question, a control group would be ethical because, as far as I am aware, there are have only been short term trials done with beetroot juice/capsules with blood pressure as an outcome so there isn't yet any compelling evidence that giving people beetroot juice is beneficial in the longer term. You have to do an RCT to demonstrate this.

I'd suggest that over the next month you take a look at the Good Clinical Practice training website and familiarise yourself with what the NIHR can offer (if you aren't NIHR funded you will need to find out what you have to do to get NIHR Portfolio status for your study - everything is so much easier if you have this, also I would think you will want to investigate your local clinical trials unit at some point in your first few months - although their involvement is likely to be expensive). Also frighten yourself by looking at the NHS ethics process and IRAS.

Best of luck.

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