From the New York Times.
One one question today: How would you evaluate an intervention to improve vaccine confidence?
In reply to | Sujit Rathod
Re: LSHTM's Prof Heidi Larson & vaccine confidence
by | Catherine Bunting -
I found the article fascinating but the question really hard!
At first I thought that a randomised controlled trial would be the best way to evaluate a vaccine confidence intervention. But then I thought about a couple of challenges:
- vaccine confidence is in part a social phenomenon - people share their knowledge and concerns with each other - so do we want to estimate the effect of the intervention at a community level rather than at an individual level?
- can you recruit people to a trial that is designed to test whether their perceptions and attitudes towards vaccines change? Would you be willing to take part in a trial of an intervention to increase your confidence in vaccines if you had very strong concerns about vaccines?
So then I thought that the best approach might be a cohort study that seeks to replicate a cluster randomised controlled trial as far as possible:
- identify a number of appropriate 'clusters' based on who the vaccine confidence intervention is aimed at e.g. GP practices, antenatal clinics
- randomly allocate a sample of those clusters to receive the intervention; the others receive no intervention, or the provision of standard information about vaccines
- take baseline measurements of individuals within all the clusters (socio-economic, demographic, perhaps social media use?)
- follow up individuals and record vaccine uptake; test whether level of vaccine uptake is different in the clusters that took part in the intervention and the clusters that did not take part
What do you think?
At first I thought that a randomised controlled trial would be the best way to evaluate a vaccine confidence intervention. But then I thought about a couple of challenges:
- vaccine confidence is in part a social phenomenon - people share their knowledge and concerns with each other - so do we want to estimate the effect of the intervention at a community level rather than at an individual level?
- can you recruit people to a trial that is designed to test whether their perceptions and attitudes towards vaccines change? Would you be willing to take part in a trial of an intervention to increase your confidence in vaccines if you had very strong concerns about vaccines?
So then I thought that the best approach might be a cohort study that seeks to replicate a cluster randomised controlled trial as far as possible:
- identify a number of appropriate 'clusters' based on who the vaccine confidence intervention is aimed at e.g. GP practices, antenatal clinics
- randomly allocate a sample of those clusters to receive the intervention; the others receive no intervention, or the provision of standard information about vaccines
- take baseline measurements of individuals within all the clusters (socio-economic, demographic, perhaps social media use?)
- follow up individuals and record vaccine uptake; test whether level of vaccine uptake is different in the clusters that took part in the intervention and the clusters that did not take part
What do you think?
In reply to | Catherine Bunting
Re: LSHTM's Prof Heidi Larson & vaccine confidence
by | Ari Fogelson -
From what I remember of Larson's book, it seems the focus of her research is not on clinical trials of behavioral interventions. This fits with the focus on listening and understanding the fears of those who are vaccine hesitant. But more than that, the larger issue of vaccine confidence as she traces it is not just about lack of information / misinformation, she describes it as often tied up in local and global politics. So the question of what sort of intervention to measure is also difficult. Larson discusses at length the epidemiological dimensions of vaccine rumors and to some extent how that might allow for interventions that prevent its spread. But, she points out that these rumors also jump from place to place in unpredictable ways and sometimes "hibernate" only to be triggered by other events and that the disruption of information on one outlet will not prevent the underlying emotions from appearing elsewhere (although perhaps not related to vaccines?). Larson focuses on building confidence in public health bodies as the long-term strategy—I don't recall if this involves measuring confidence in public health bodies as an outcome. From what I recall, she draws a lot on routine data related to vaccine uptake rates as well as some observational ecological studies of attitudes toward vaccines or exposure to vaccine rumors. She is able to use data on uptake rates to show the impact of events that reduce trust in the relevant medical authorities as well as to show some interventions that seemed to have worked. Most of these deliberate interventions would probably be classified as temporal ecological studies. Some may be segmented geographically.
The NYTimes article mentions changes in communication around vaccine trials and observation of trial participation rates. The article suggests there was a high rate of participation in the study where they changed how they communicated about the trial and the vaccine. It did not seem like they did a formal comparison to other trial participation rates, maybe there was an effect observable over time when the researchers changed tack.
The NYTimes article mentions changes in communication around vaccine trials and observation of trial participation rates. The article suggests there was a high rate of participation in the study where they changed how they communicated about the trial and the vaccine. It did not seem like they did a formal comparison to other trial participation rates, maybe there was an effect observable over time when the researchers changed tack.
In reply to | Catherine Bunting
Re: LSHTM's Prof Heidi Larson & vaccine confidence
"follow up individuals and record vaccine uptake; test whether level of vaccine uptake is different in the clusters that took part in the intervention and the clusters that did not take part"
This was a really interesting answer and a great perspective on this issue. If the intervention was a health promotion campaign based on dispelling the various myths regarding vaccine safety. I feel a qualitative study based on surveys and focus groups might be a cheaper and easier way of assessing the impact of the intervention.
I really like your idea of using clusters such as GP practices and within this setting, it would not be too difficult to get participants to fill out questionnaires regarding their attitudes to vaccine safety both before and after the intervention. While your cohort study idea would have far more statistical strength, a qualitative approach might give us more understanding as to the reasons behind vaccine hesitancy, as well as being cheaper!
This was a really interesting answer and a great perspective on this issue. If the intervention was a health promotion campaign based on dispelling the various myths regarding vaccine safety. I feel a qualitative study based on surveys and focus groups might be a cheaper and easier way of assessing the impact of the intervention.
I really like your idea of using clusters such as GP practices and within this setting, it would not be too difficult to get participants to fill out questionnaires regarding their attitudes to vaccine safety both before and after the intervention. While your cohort study idea would have far more statistical strength, a qualitative approach might give us more understanding as to the reasons behind vaccine hesitancy, as well as being cheaper!
I haven't actually had to deal with a lack of vaccine confidence in practice but an intervention of that nature will have to look at 3 different groups and three different situations or context at 2 separate times- before and after the intervention. It doesn't just look at whether or not the person will take the vaccine but their ideas or beliefs surrounding the vaccine,the value of having rights and freedoms and it's effect on their bodies and others around them . These are quite difficult to measure in an unbiased manner and there may be the idea of pressure change their minds in an objective research setting. There are also various levels of vaccine confidence with every different vaccine.
BEFORE THE INTRODUCTION OF THE INTERVENTION:
BEFORE THE INTRODUCTION OF THE INTERVENTION:
I would have to conduct a qualitative or interview-based study with some selected stakeholders to get a picture of the issue.
To evaluate such an intervention I would have to conduct a cross-sectional study based on the findings of my qualitative study to ascertain the prevalence of vaccination, socio-economic status, demographics, as well the opinions of parents, patients and providers in selected communities on:
-recommended vaccines;
-providers who administer vaccines
-processes and policies that lead to vaccine development, licensure, manufacturing,
FOLLOW UP
I would use a Randomised Control study and the vaccine under focus will be the yearly flu vaccine.
This will provide baseline information on the current state of vaccine confidence in across the various groups. These three groups will then be divided randomly divided into two classes within each group according to whether they had the intervention or not.
example:
Providers with intervention vs Providers without intervention
Parent's with intervention vs Parent's without intervention
Patient's with intervention vs Patient's without intervention
These people will be followed up for about a year and will be screened on a quarterly basis as to their opinions concerning news circulating about the selected vaccine and their desire to take them, at the end of the year a measure of vaccine uptake will be done and opinions about the particular vaccine will be ascertained.
To evaluate such an intervention I would have to conduct a cross-sectional study based on the findings of my qualitative study to ascertain the prevalence of vaccination, socio-economic status, demographics, as well the opinions of parents, patients and providers in selected communities on:
-recommended vaccines;
-providers who administer vaccines
-processes and policies that lead to vaccine development, licensure, manufacturing,
FOLLOW UP
I would use a Randomised Control study and the vaccine under focus will be the yearly flu vaccine.
This will provide baseline information on the current state of vaccine confidence in across the various groups. These three groups will then be divided randomly divided into two classes within each group according to whether they had the intervention or not.
example:
Providers with intervention vs Providers without intervention
Parent's with intervention vs Parent's without intervention
Patient's with intervention vs Patient's without intervention
These people will be followed up for about a year and will be screened on a quarterly basis as to their opinions concerning news circulating about the selected vaccine and their desire to take them, at the end of the year a measure of vaccine uptake will be done and opinions about the particular vaccine will be ascertained.
In reply to | Afua Agyei
Re: LSHTM's Prof Heidi Larson & vaccine confidence
Dear all
I also think it is a fascinating - and urgent - topic and a very interesting discussion.
Regarding using qualitative methods, I would also perhaps combine them with quantitative in a mixed methods approach, for example using qualitative methods in trial design phase and quantitative methods for trial analysis.
I agree that an RCT would probably be the best way to evaluate an intervention on vaccine acceptance. The control arm would probably receive the usual level and type of information about the vaccine in that community (no intervention) and the intervention would consist of a carefully crafted communication / awareness campaign. I agree with the cluster-level randomisation to minimise 'contamination' between trial groups.
I also think it is a fascinating - and urgent - topic and a very interesting discussion.
Regarding using qualitative methods, I would also perhaps combine them with quantitative in a mixed methods approach, for example using qualitative methods in trial design phase and quantitative methods for trial analysis.
I agree that an RCT would probably be the best way to evaluate an intervention on vaccine acceptance. The control arm would probably receive the usual level and type of information about the vaccine in that community (no intervention) and the intervention would consist of a carefully crafted communication / awareness campaign. I agree with the cluster-level randomisation to minimise 'contamination' between trial groups.
- I guess that there could be an ethical element involved if vaccination had documented effectiveness in the study population and the health outcome was severe.. here one could argue that everyone should receive targeted reinforced messages and be part of the awareness intervention and an observational study would be more appropriate
I also like the above proposal to measure outcomes both via survey of attitudes and actual vaccine uptake, the latter based on medical records for example.
I also like the above proposal to measure outcomes both via survey of attitudes and actual vaccine uptake, the latter based on medical records for example.