Deciphering Graphs: Giving Actual Informed Consent

To be an informed parent, we have to do our own research.  I’ve gone through a process from trusting the information handed to me by professionals to learning to do my own research. It didn’t hurt that I learned in college where to find the information and how to decipher data sets and understand statistics. Not every parent has that luxury, and it makes giving informed consent difficult.

Doctors are supposed to acquire informed consent from parents before performing procedures on, giving medications to and administering vaccines to our children. In my opinion, we are never fully informed. We are informed only as minimally as possible, in most instances.

To be informed, we must be able to see the big picture.

As I began to educate myself, I quickly learned that data sets can easily be manipulated to show true data, but a false picture.

To demonstrate this, I am using a data set of mortality rates for the United States. The information was acquired from:

Vital Statistics of the United States, U.S. Bureau of the Census

Vital Statistics of the United States, U.S. Public Health Service

Vital Statistics of the United States, Mortality, U.S. Department of Health, Education, and Welfare

Vital Statistics of the United States, Mortality, U.S. Department of Health and Human Services

Historical Statistics of the United States, Bureau of the Census

 

When figuring death rates, deaths are noted per 100,000 people. This gives a more accurate idea of what is happening as a population grows. In this data set, data from 1977 and 1978 could not be acquired and is missing.

The following graph shows the entire historical data set for death rates from the infectious diseases, whooping cough (pertussis), Measles and Scarlet Fever. This is a very basic set up. It shows all three diseases and their death rates from the turn of last century until 1987.

Data Set Std Axis 1900 to 1986

 This data set shows two vaccine “preventable diseases diminishing as the century progressed. It also shows Scarlet Fever, which is caused by a Strep infection also diminishing as the century progressed. This is not the presentation we are shown typically by professionals or the media. The graph uses a standard, incremental vertical axis. Notice the space between the lines on the vertical axis grow at a set rate, by 2’s. The vertical axis represents deaths per 100,000 people in the US.

Logarithmic Scaled Graphs

We are often shown a different presentation of this data set:

Data Set Logarith Axis 1900 to 1986

This is a logarithmic scale. The purpose of using this type of scale in graphing is so that as numbers get smaller, on a grand scale, you can see the smaller data more accurately. It certainly works to analyze data, but when presented to the general public without being explained, this style of graph shows a picture that can be misinterpreted. This is the exact same data set, but the graph looks very different.

The reason for the difference in appearance is that the vertical axis is exponentially growing. The increments between lines of the vertical axis do not represent the same amounts.  Locate the number one on the vertical axis on the left hand side of the graph. Go up one line. The next line is 10. Many people do not even look at these numbers and presume a basic understanding of graphs. This presumption would cause people to believe that the space between lines would be 10. Since this uses a logarithmic scale though, it’s exponential, and the next line is at 100. So, when you start at the very bottom of the graph and move your way up between lines on the vertical axis, the difference between two lines will be ten times the amount of the difference between the lower lines of the chart.

You need to understand this to have an accurate understanding of the big picture if you are ever presented with a graph like this.

Choosing Data Sets

Another complication of providing data is in the choice of data sets. Often, we will be presented with data sets that don’t show the entire picture based off of presumptions. For example, one presumption is that vaccine preventable disease deaths were eradicated thanks entirely to vaccines. So, to show the decline in deaths from vaccine preventable diseases, we are shown a graph of only vaccine preventable diseases:

Data Set Logarith Axis 1900 to 1986 no Scarlet Fever

In this logarithmic scaled graph, all we needed to do to take out the possibility that other things affected the death rates of diseases that had vaccines created to prevent them. We do not have a scarlet fever vaccine. Scarlet fever, of course, as shown above, still declined. That could indicate that other factors were also at play. Deleting the scarlet fever data set, completely eliminates that factor from contemplation.

Learning to Consider Other Factors

There are so many factors that go into understanding information well enough to make actual informed consent. Take the historical data from the Flu of 1918 as an example.

You can vastly change the appearance of a graph depending on when you start a graph. When we add in deaths from “Influenza and Pneumonia” you can more adequately see that sometimes, there are significant variances of death rates.

Data Set Std Axis Adding FLu and Pneumonia Together

The large spike in influenza and pneumonia was from the Spanish Flu. They tell us that this could happen again at any time. It’s important that we use data wisely. The Spanish Flu didn’t just “spontaneously happen” in 1918. We must also consider what was happening in the world. It wasn’t anything insignificant. 1918 brought the armistice that ended the first world war. Our servicemen were coming home. They were bringing home with them a new strain of flu.  Of course, their resistance was down, given what they were returning from, and many were ill with the new strain.

During the Great World War, another major thing was happening that played a role in the death rates from the flu of 1918. Bayer had been in a legal battle over aspirin. In part a result was that aspirin, which was previously labeled for “aches and pains” was suddenly also being marketed as a fever reducer and aspirin was so novel and exciting that even the US Surgeon General recommended aspirin for treating the fever from a flu just before the spike in flu deaths in 1918.

Of course, now we know that fevers are actually good at stopping viral replication that could otherwise lead to pneumonia, and also that aspirin and the flu simply do not mix.

The point is, you can look at this graph and be told that this could happen again at any time, or you could look at this graph and also consider what was going on in history at that time.

Another thing to consider is that over the years, causes of death have gotten re-categorized and given subcategories. Now, we can look at death rates and see which deaths were caused by the flu and which were caused by pneumonia or even other bacterial infections. In the past, we could not. We have to consider these factors when making decisions for our children. We cannot allow a graph to be flashed before us, with a horror story and make informed decisions based on such limited information.

This was not meant to be an anti-vaccine post. I do not want to tell you what to do with your children. I do however want to help you realize how limited our informed consent often is. These are our children, we cannot afford to give less than informed consent. We must learn how to look at data from a number of angles and see the bigger picture.

7 Comments

  1. Paul Davis

    If I was to decipher these graphs I’d sooner want both x and y axis labelled. The x axis is the horizontal one and should be labelled YEAR (no units required). The y axis is the vertical axis and should be appropriately labelled for deciphering. In this case, mortality rates per (r) amount of people. As this is not labelled I’d draw absolutely no conclusion from this. And nor would a 13 year old science student who would be asked to complete their graphs before making any comment.

    The data here is useful in indicating that as time progressed mortality rates dropped. There is certainly no correlation here between time and vaccination status. There’s more of a correlation between time and medical abilities or facilities than anything – as at least one disease there isn’t even vaccinated for.

    Other important factors to take into consideration – I’ve actually never seen a vaccine page (supporting vaccines) use these graphs to demonstrate anything more than medical advancement.

    In further conclusion it can be said that without further analysis, zooming in on the intercept (ie 0,0) you won’t have any representable data for vaccines at all and therefore drawing a conclusion that vaccines have not worked will not be possible from the current data displayed here.

    In order to prove that vaccines haven’t worked it would be much more appropriate to display incidence data – that is the number of incidences vs the year. Using similar (but labelled) axis. When you provide that data then you’ll be able to make the commentary that you’ve made – that vaccines have not in fact helped lessen the effects of vaccine preventable diseases. That is of course if your data actually suggests that.

    For example, http://upload.wikimedia.org/wikipedia/commons/e/ed/Measles_US_1944-2007_inset.png (you can always find a reference for that data if you’re not happy with Wikipedia – it’s merely an example).

    This shows that measles was already low when the vaccine was introduced to the USA. When I say low, I mean around 400,000 cases (x and y axis is appropriately labelled in this case). The number of cases quickly dropped to less than 1% of that number in only a short time. I think even the most ardent anti-vaccine lobbyist would not argue that the measles vaccine isn’t successful. They’d be crazy to when data like that is presented.

    • Dawn

      Oh boy. Except, that your presumption is that I’m trying to prove vaccines didn’t work. That has nothing to do with this particular article. This article was just to open people up to the idea that they should take a good look at how data is presented and the historical context as well.

      If you read through to the end, this was not meant to actually make a statement about vaccines at all, merely to demonstrate how the numbers can be visually changed depending on how it’s visually portrayed. The entire article IS the labels you are looking for. I feel that you are trying to turn this into something it was not meant to be. I wasn’t trying to say vaccines did or didn’t work.

      I was trying to encourage parents to learn how to give actual informed consent.

      While you may not have seen a pro-vaccine page use graphs like these, I have. The CDC uses logarithmic graphs and so did my pediatrician.

  2. Luci B

    Now, for some accurate and legitimate graphs (which are labelled correctly!):

    http://www.science.org.au/policy/documents/Figures/AAS_Fig%203.1.pdf

    Yes, measles deaths were on the decline due to improved standards of living, including improved medical care which allowed sick people to survive. However, notice that deaths from the disease continued dropping even in the 70s, 80s, 90s and 2000s (during which time standards of living such as hygiene, nutrition and medical care did not change significantly).
    Notice, in particular, the 2 graphs at the bottom. These 2 graphs show *cases* of HiB and Meningococcal Type C which dropped drastically right after the vaccinations were introduced, in 1993 and 2003 respectively. There have been negligible changes in living standards, or “other factors” in Australia since 1993 that would account for the drop in *cases* of these illnesses following introduction of vaccination. So, tell me, if it wasn’t vaccination, how do you explain the sudden drops in cases of HiB and Meningococcal Type C?

    • Luci B

      PS: these graphs are from the Academy Of Science information booklet on vaccination:

      http://www.science.org.au/policy/documents/AAS_Immunisation_FINAL_LR_v3.pdf

      But let me guess, you’ll dismiss them because they come from a legitimate source. Because the Academy of Science is legitimate and doesn’t support conspiracy theories about the government trying to murder babies, you will claim the Academy of Science is corrupt and tries to mislead parents because….well, you’ll have to explain why they would do that. According to you, parents should either make up their own graphs when they know little about statistics, or they should only trust graphs made up by bloggers who claim they are “educated”, misunderstand the data, while presenting unlabelled graphs in a misleading fashion. Well done.

    • Dawn

      This is not an anti vaccine post. This is about showing parents how to figure out if the image before them shows the actual whole picture and teaching them to decide for themselves.

      The graphs you posted, just so you know, are far more truthful than the graphs I was ever presented with as a parent. I would prefer to see death RATE, as opposed to actual numbers, even though, presumably your population grew. If I were simple an anti-vaccine activist alone, your numbers would be preferred because they are simply actual numbers of death or actual number of cases. Showing it as a rate instead would probably demonstrate and even more significant decline. presuming the population grew during as the years went on. Even still using the actual rate, shows more adequately, the bigger picture. I prefer the bigger picture, regardless of what it “says.”

      You make presumptions about me that are based on what you know of other bloggers. You have decided to turn this into an anti-vaccine post, when all it is is showing different ways we are presented data. If I wanted to prove an anti-vaccine stance, I would have inserted the years that vaccines were made, introduced and introduced to a wide group of people.

      Unfortunately, as soon as someone brings up the possibility that parents should step back and question data given to them, it is viewed as an assault against the entire concept of vaccines.

      You asked a legitimate question though about the drops in deaths of HiB and Meningococcal Type C, and I would encourage you to look at if those deaths were replaced by a different strain not covered by the vaccine. With pertussis that was the case, and I recall seeing something about how that was the case with HIB being replaced by other stereotypes of HI, but given that this is not supposed to be an anti-vaccine post, I will leave it in the frame of letting you either accept what you know or look for more information based on what I’m suggesting. There’s plenty out there. I wouldn’t suggest that the HIB vaccine was useless, but would suggest that parents not rely on that as an assurance that their children will maintain healthy, because other strains exist too, and some evidence shows the other strains are moving in. There is, you can’t deny, reason to believe that when it comes to bacteria anyway, that when one strain goes away, a different strain or mutated strain often moves in in its place. Extended breastfeeding and proper nutrition are still crucial, and should be stressed profoundly more than it is at every pediatric appointment. My own children ARE vaccinated against HIB, but I don’t want to tell parents what to do about vaccinating. I want to encourage them to dig deeper and use that information as a tool to have real thorough discussions with their pediatricians. This post was about making informed consent.

      Too often parents make decisions based on either “standard recommendations” from the CDC or else “anti-vaccine bloggers.” I would rather they look for information themselves and then take it to their pediatrician for discussion. Children and families have different needs and different risks.

      Certainly, you would want the same, right? You do encourage actual discussions with pediatricians about risks and benefits, don’t you? You do encourage parents learn all the information they can and have open dialogue with their doctors don’t you? They may end up skipping or delaying a vaccine they were going to get (Like Hep B or Chicken Pox for example) but may end up getting one they wouldn’t if they relied on blog posts alone (Like HIB for example.)

      Or is your preference for parents to not actually give informed consent, but just consent? I’m not being argumentative when I ask that. Some people believe that since the vaccine era has reduced so many preventable diseases that it’s worth the risks and that it should just be standard. I believe though that people need to look at their own situations, all the data they can, the risks and benefits and decide what to do with their doctor on a vaccine by vaccine, medicine by medicine, procedure by procedure basis. I don’t think it’s ethical to sacrifice some who are sincerely at a greater risk for side effects than they would be for the diseases merely for the greater good.

      Now, to address the decrease in measles deaths during the later period of time, you must certainly agree that that was also the generation when daily multivitamins for children was becoming standard. That may account for the more rapid decline than we had been seeing prior to the introduction of the vaccine as indicated by the red arrow. Just a thought, but certainly not scientific proof. But, to put it into perspective, in 1900, in the US, the rate of death from measles was 14.3 (per 100,00 of course). It dropped as low as 2.3 in 1925, but the next year rose to 8.2. The average rate kept dropping. In 1963, a measles vaccine was licensed. By that point, the rate had been wavering back and forth between .3 and .2 (per 100,000 of course) for nearly a decade. In 1963, the death rate was .2. In 1964 it was .2 again. In 1965, it was .1. In 1966 it was .1 again. Then it was zero from then on out. Now, actual measles cases were still seen in the years that preceded the vaccine, but the death rate was already only .3 or .2 per 100,000 people. Total people, not just healthy infants and children. So, that’s something people have a right to understand. I know that as a parent, I was told, as I got my kids vaccinated that it was a very dangerous disease and that I simply could not take that risk of not vaccinating them. I was led to believe that if they got measles, there was a very real risk they would die from it. But, looking at this data, that wasn’t really true. Who knows, if I had had this information, maybe I wouldn’t have gotten them vaccinated. Maybe I still would have. I can’t say for sure, but I certainly don’t appreciate the scare tactic I was given at that time and I don’t think it’s fair. I deserved to know this information. I also deserved to know what other complications could have come from measles and what the actual chances were of those complications. I had a right to know how significantly getting enough vitamin A for example impacted the risk of complications. I also would have liked to have been told that there are even some long term health benefits on the immune system from actually getting it. And I also had a right to know what the risks of vaccination were for my children SPECIFICALLY who had a family history of autoimmune disease and allergies to specific ingredients in the vaccines themselves, for example. I just don’t feel the bar is set high enough on giving parents the whole picture. I see nothing wrong with parents being given all of the actual information at their office visits. Except maybe that it may take too long, but I feel our children are worth it.

  3. Genevieve

    The sad part is that my own pediatrician didn’t give me ANY data, just told me the diseases were horrible, how she had seen so many children dying of them when she did Doctors Without Borders and how I was putting my child at risk if I didn’t get her vaccinated. I wish doctors would have a discussion with their patients instead of scare tactics. I’m college educated, I consider myself to be pretty smart. I am not a doctor, but I would have preferred a discussion and some information (I didn’t even get the vaccine inserts, just a flyer about the vaccine and the dangers of the diseases) to make a decision that is knowledge based vs fear based.

    • Dawn

      G- I absolutely believe that she saw so many children dying from these diseases. I really do. I’m sure that was horrifying. We also have to keep in mind though that they also lack clean water supplies, septics and sewers often, deal with parasites, and inadequate nutrition. Those are big deals. Who knows how much better the children’s outcomes would be if they addressed even just one of these issues as well. You know? It needs to be considered. Because disease or no disease, they many will still die from other infections if these weaknesses are not also addressed.

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