> Useless statistics and chicken pox (article created 23/02/06)
Useless statistics and chicken pox
I've been feeling very ill over the past few days, with blistery spots appearing over my body, so I went to the hospital today to find out the prognosis. It turned out I had chicken pox. I was bound to get it sooner or later, since I never had chicken pox when I was a kid (I'm 28 now). It's apparently more serious in adults than children, and though the odds are very small, I could develop permanent scars, pneumonia, brain damage, and a whole assortment of other tasty goodies including death itself.
At the hospital, I was asked whether I would like to take a prescription involving certain drugs to relieve the symptons, and make it heal faster. There were advantages and disadvantages. If I'm at the worst stage of the pox (when most spots appear), then I'm only going to get better, and taking the drug wouldn't be of much value. However, it could stop the chicken pox from getting worse, thus leading to the complications described in the first paragraph. So why not take the drug anyway you may ask? Well, unfortunately, the drug has an array of equally appetizing side effects, including vomiting, diarrhea and many others I can't remember. Most significantly, there was a small possibility of developing sever liver problems by taking the drug.
So I've got a choice between a presumably minute chance of developing brain damage or pneumonia if I DON'T take the drug, and liver problems if I do.
And the likelihood?
I then proceeded to ask my doctor what the chances were that I would develop the aforementioned conditions, by asking something to the effect of:
"So what's the probability that I will develop brain damage if I don't take the drug?"
She answered to the effect of:
"Well that won't matter if you're the one who gets it in the end"
Oh common, basic logic here! If there's a 10% chance of developing something serious, that would be far worse than a 0.001% chance! We don't what the outcome will be, but the point is, probabilities can help us to make an informed decision and weigh the risks. Anyway, I replied:
"Yes, but if there's a 1 in 10,000,000 (0.00001%) chance that I would develop brain damage, that would be far preferable to a 1 in 10 chance (10%)"
I think she got the point then, but it's all quite worrying, and doesn't bode well for other hospitals and medical knowledge in general. I must add that she seemed an otherwise highly intelligent and conscientious lady who certainly knew her stuff. In the end, she apologized about the lack of hard data, and this got me wondering; is this kind of data available anywhere? After all, chicken pox is hardly a new virus!
Data, data, everywhere, but not a drop to drink
So I started out on my quest to see if this information was available on the internet. Specifically, what was the chance of developing pneumonia, brain damage, or even death, as a result of a chicken pox infection in adults. Here are just a few of web sites I visited, courtesy of Google...
"It is important to note that when adults get chicken pox disease it is usually more severe, often developing into pneumonia."
Often? How often!? That could be anything from a fraction of a percent to 50%!
Adults and adolescents with chicken pox are at some risk for serious pneumonia, which should be suspected if coughing and abnormally rapid breathing develop.
"at some risk"? Is that around 20%???
"Chickenpox for grown-ups can mean pneumonia, encephalitis -- inflammation around the brain covering -- bacterial infection of the skin, and even problems with the kidneys, heart, liver or joints."
...With the operative word being "can". Again, that could be any percentage under the sun.
"About 14,000 people are hospitalized because of chicken pox and approximately 100 people die of chickenpox every year."
This tells us little about the PROPORTION of adults who die if they had chicken pox.
"Up to 25 percent of adults who get chicken pox get pneumonia. The hospital admission rate for adults with chicken pox is up to 10 times higher than for children, he added."
"Varicella pneumonia is the most common complication in adults. Estimates of its incidence varies, between 16 to 25% in most reports"
At last - some raw information! Okay, after hours of searching, that's what I was looking for. Now let's see if we can find any information regarding the percentage of adults with chicken pox who die or get brain damage.
"Adults have the greatest risk for dying from chicken pox, with infants having the next highest risk
For example, in the UK where there is no widespread vaccination program, about 25 people die every year from chicken pox."
Not what we're looking for. Nor is...
"In England, where chicken pox vaccinations have not been recommended, adults account for 81% of all deaths from chicken pox."
No no no. I want to know how many adults who have chicken pox actually die! That would be a much more useful statistic!
"Chickenpox is usually mild in children but can be severe in adults and lead to severe skin infection, scars, pneumonia, brain damage, or death. Each year, nearly 11,000 people require hospitalization and 100 die due to complications."
Well, we have the information that 100 people die, and that 11,000 people require hospitalization, so we can deduce that at the very most, 1% of adults who get chicken pox will actually die from it, but it's probably much less that this. How much less? We still don't know.
Those pages are a fraction of the web sites I visited (and I searched Google Scholar too), but in the end I didn't find what I was looking for. Is this because of a lack of data, or is it because people don't care about this kind of information? If it's the latter, then people should be informed that these kind of basic statistics can save lives and help prevent complications, especially when there's a choice to be made involving whether or not to take drugs to help a condition.
In the end, I survived my chicken pox unscathed. As I type this, I have almost fully recovered, and managed to escape the various complications that can arise from an infection. But this may not have necessarily been the case. I would loved to have known the potential of secondary infection and prescription risks so as to decide what to do next. At the least, this kind of information should be available at hospitals and to professionals. But more preferably, this data should become public knowledge, available on the internet to all who care to ask.
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