I’m stuck on one of my papers, so that’s what I thought I’d write about today. You get to see a little about how the science sausage is made and, hopefully, by explaining this paper to you lovely people I can figure out what exactly all this nonsense means!
As I’ve mentioned a few times now, I’m a research psychologist (i.e. not the type that asks you how stuff makes you feel). I study the acceptance, hesitancy and refusal of vaccination. I don’t do any of that squidgy biological science that goes into the actual development and evaluation of vaccines (although I do work closely with those that do), instead I look at public perceptions and beliefs towards the evidence based recommendations that are arrived at through their extensive work. If you’re interested in my personal views on vaccination I wrote a post a while back on this topic: Why I choose to fully vaccinate
The PhD
My PhD focuses on one small aspect of the Psychology of Vaccination: Vaccine information seeking behaviour.
Most people vaccinate automatically when their doctor recommends a particular vaccine. I’m interested in what happens when, instead, people actively weigh up the pros and cons of vaccination and seek out additional information to aid in the decision making process. If people seeking information what information are they looking for, what do they find and does this information have an effect on whether they vaccinate or not? This seeking can involve asking questions in a consultation with a health care professional, searching online, talking to friends and family members, watching TV news or any other way of gathering information.
I don’t personally design intervention strategies to increase vaccine uptake rates at this point in time but it’s conceivable that some of my research will eventually be used to inform vaccine communication strategy in the future (if that is I can get this damn paper finished)
The Paper
Currently I’m in the process of writing up a systematic review (see the blue box for a simple overview of systematic reviews) on vaccine information seeking and scanning behaviours.
Vaccine information seeking behaviour is when people actively put effort into collecting information on a particular vaccine or vaccination in general in order to aid in their decision making. Vaccine information scanning behaviour, on the other hand, is when people passively acquire information about vaccination during the course of their everyday life.
With this paper, we want to find out:
How other academics have studied these concepts in the past.
How often people seek additional information about vaccination.
Where they are seeking this information from?
Does this seeking influences their final decision to accept of refuse a particular vaccine?
With this in mind, we set out to find the peer-reviewed papers that could help us answer these questions. First, we went wide and found around 700 papers that might be of use to us, we whittled away at these until we were left with 34 papers that were exactly what we were looking for. After reading and making extensive notes on these papers, we found that they referenced a number of other great paper that we didn’t find in our initial search so we tracked those down and added them to our big stack of papers, and also by that point a few more had been published so we added them to the pile too. This lead to a final count of 54 papers that all touched on our topic of interest.
That last paragraph took around two and a half months, and this is quite a small review
The Findings
Prevalence
Trying to make sense of this many papers on a similar topic can be tough. Rarely do any two papers examine the same concept in exactly the same way. Each paper usually has its own spin on a topic and may not even be interested in the same outcome as you are.
We got quite luckily here, firstly 53 papers is a somewhat manageable number of papers and secondly most of the papers were surveys that examine the vaccine decision-making process for a specific vaccination (e.g. the HPV vaccine or the 2009 H1N1 influenza vaccine) or childhood vaccination in general. The rest were either interviews or focus groups related to the vaccine decision-making process or analytics of online search engine use.
Several of the survey studies reported their findings in such a way that we could pick out data indicating how many participants searched for information about a particular vaccination. From those papers we put together this forest plot:
The size of the box represents the number of participant that were in each of the study (this ranged from around 100 to 4000), their position across from left to right represents the percentage of the participants that actively searched for information about vaccination. (Note: this is likely not the final version of this image and should be taken with a handful of salt for the time being)
This was a bit of a shock for us, it seems that a big chunk of people are seeking out information about vaccination to inform their decision making. The stand out result here is for the vaccination that was available during the H1N1 influenza outbreak during 2009. It would make sense for this to generate such high levels of seeking, the news media at the time gave the outbreak a great deal of coverage. This likely prompted people to look for more information about the vaccine as a form or protection from the virus (in fact this has been supported by some of the interview papers we have in our review).
If we put the H1N1 vaccine to one side for a moment it would seem that still around 40% of people are seeking out information about vaccination. Interesting, not sure what to do with that piece of information at the time being but interesting none the less.
From these papers, we can also look into the numbers a little deeper and find out what factors predict searching for information about vaccination. I won’t go into this in much depth here but the most common factor that shows up in these studies is level of education. The higher people’s qualification level the more likely they are to seek out additional information during the vaccine decision-making process.
Fewer studies investigated vaccine information scanning (the passive acquisition of vaccine information). Probably because it’s much harder to measure. When studies do it seems to be more common than the seeking behaviour, for the H1N1 Vaccine and the HPV vaccine at least, which would make sense. With only around 5 studies in our review touching on this topic I think we could learn a lot from studying this process of passive information acquisition in some more detail at some point in the future.
Channels and sources
Ok, this is where I got stuck for a while earlier in the month. I think we’ve got two separate concepts being talked about in these studies that are important that I separate out for, information channels and information sources.
An information channel is the means through which information is acquired (e.g. Broadcast media, the internet or friend and family members). An information source is the specific originator of information (e.g. The World Health Organisation, Natural News or The Guardian).
Most studies don’t make this distinction. When they ask their participants where they sought out information from and give options for participants to choose from the studies just sort of mush sources and channels together. So, one of the main points I want to make with this paper is that there is a difference between the two concepts, especially when it comes to the internet. Under our definition, the internet is not a source of information, it’s a channel. Sources exist on the internet, some of them are reliable some of them are not so reliable, some of them may even be friend and family members if social media is taken into account. The internet therefore isn’t really a source of information, and treating it as such probably doesn't give us any useful findings as it will mean something vastly different depending on who is asked. It’s a minor point but some more nuance here in the future may make our measurement better (although this distinction does make for a complete pain when trying to write about the subject).
When it comes to channel/source use this is how the different vaccines compare:
This is 14 studies that asked people to report various channels/sources used when making a vaccine decision. I’ve re-categorised, taken a weighted average of each and separated them out by vaccination (HCS = Health Care System, HCP = Health Care Professional). Again, this is likely to change before the final publication comes out so don’t get overly attached to it.
Some nice little findings in here, the difference in broadcast media usage between childhood vaccines and other vaccines for instance. Also internet use for maternal vaccinations compared to other vaccines, although this finding is based on just the one study, so potentially a good indication for more research being needed here (which luckily I have coming along in my next study).
Just as with the prevalence of the vaccine information seeking behaviour, the use of many of the channels and sources of information can be predicted through the measurement of other variables. The main finding here looks to be attitude towards vaccination. How people feel about vaccination appears to relate to the use of channel/source for information acquisition. This could mean a few different things:
The use of certain channels/source of information are having an effect on attitude towards vaccination
Peoples attitude towards vaccination is effecting their choice of channels/sources for information acquisition
Both
It’s very likely both to some degree but it’d be very interesting if we could pick out a cause and effect from this correlation at some point as I feel the second point isn’t something that has had much attention in the literature.
Impact
So what does all this searching actually mean for uptake? Well it appears to be a bit of a mixed bag from what I’ve seen so far. Here is another forest plot that I’ve been having a play around with lately (its still not as clear as I'd like it to be, much more work needed I think. Also may just drop it.
The plot is separating each study into two data points, the percentage of those that sought information and accepted the vaccination and the percentage of those that sought information and rejected vaccination (Important note: this is not the percentage of people that accepted or rejected vaccination, the vast majority are accepting the vaccine in each study).
It looks like in some studies seeking information about the vaccine relates to people being more likely to vaccinate (e.g. Health care professionals for their seasonal influenza vaccination) while in other studies seeking information about vaccinations relates to people being less likely to vaccinate (e.g. Brunson et al, childhood vaccination).
There are many other factors going on here for sure. My next step is to dig into these relationships in more depth, I have a strong suspicion the interviews and focus groups will flesh these finding out nicely.
And then at about this point the paper trails of into nothingness…
What’s next then?
Thanks for letting me write at you all for the last almost 2000 words, I know what I have to do now! It’s the same thing I have to do literally every time I get stuck on a systematic review, re-read every one of the papers this time with the gaps in the review fresh in my mind. Almost there now, I hoping to have a draft ready by the end of the month. Although I did say that last month.
Sorry this post was more for my benefit rather than yours today, I’ll try and write something of actual interested next week.
About me:
My name is Richard, I blog under the name of @nonzerosum. I’m a PhD student at the London School of Hygiene and Tropical Medicine. I write mostly on Global Health, Effective Altruism and The Psychology of Vaccine Hesitancy. If you’d like to read more on these topics in the future follow me here on steemit or on twitter @RichClarkePsy.
References
I’ll give you some of the references, seeing as you’ve been very good to read this far, but there’s no way you’re having them all. I’m afraid that would be level of academic rigour that I wrote this post to avoid today!
Brunson EK. How parents make decisions about their children’s vaccinations. Vaccine [Internet]. 2013;31(46):5466–70. Available from: http://dx.doi.org/10.1016/j.vaccine.2013.08.104
Bults M, Beaujean DJMA, Richardus JH, Steenbergen JE van, Voeten HA. Pandemic influenza A (H1N1) vaccination in The Netherlands: Parental reasoning underlying child vaccination choices. Vaccine [Internet]. 2011;29(37):6226–35. Available from: http://dx.doi.org/10.1016/j.vaccine.2011.06.075
Cheung EKH, Lee S, Lee SS. Pattern of exposure to information and its impact on seasonal influenza vaccination uptake in nurses. J Hosp Infect [Internet]. 2017;97(4):376–83. Available from: https://doi.org/10.1016/j.jhin.2017.08.005
Harmsen IA, Doorman GG, Mollema L, Ruiter RAC, Kok G, Melker HE De. Parental information-seeking behaviour in childhood vaccinations. 2013;1–10.
Jung M, Lin L, Viswanath K. Associations between health communication behaviors , neighborhood social capital , vaccine knowledge , and parents ’ H1N1 vaccination of their children. Vaccine [Internet]. 2013;31(42):4860–6. Available from: http://dx.doi.org/10.1016/j.vaccine.2013.07.068
Kim S, Real K. A profile of inactive information seekers on influenza prevention: a survey of health care workers in Central Kentucky. Heal Inf Libr J [Internet]. 2016;33(3):n/a-n/a. Available from: http://doi.wiley.com/10.1111/hir.12132
Manika D, Ball JG, Stout PA. Factors Associated with the Persuasiveness of Direct-to-Consumer Advertising on HPV Vaccination Among Young Women Factors Associated with the Persuasiveness of Direct-to-Consumer Advertising on HPV Vaccination Among Young Women. J Health Commun. 2014;19(11):1232–47.
Stevens CF, Caughy MO, Lee SC, Wendy P, Tiro JA. Does language moderate the influence of information scanning and seeking on HPV knowledge and vaccine awareness and initation among Hispanics? Ethn Dis. 2013;23(1):95–102.
Walter D, Böhmer MM, Reiter S, Krause G, Wichmann O. Risk perception and information-seeking behaviour during the 2009/10 influenza A (H1N1) pdm09 pandemic in Germany. Eurosurveillance. 2012;17(13):1–8.
Weiner JL, Fisher AM, Nowak GJ, Basket MM, Gellin BG. Childhood immunizations: First-time expectant mothers’ knowledge, beliefs, intentions, and behaviors. Am J Prev Med [Internet]. 2015;49(6):S426–34. Available from: http://linkinghub.elsevier.com/retrieve/pii/S0749379715003529
Wheeler M, Buttenheim AM. Parental vaccine concerns, information source, and choice of alternative immunization schedules. Hum Vaccin Immunother [Internet]. 2013;9(8):1782–9. Available from: http://www.tandfonline.com/doi/abs/10.4161/hv.25959