Critical Enquiry

Drugs, Driving, and Airplanes: Fallacies of Risk-Taking

Judging by media reports and recent events, the average person on the street is incapable of understanding or calculating the risk involved in any given activity (by "risk," we refer to the dictionary definition the possibility of suffering harm or loss; danger.) In many cases, an individual asked to select the comparative risk involved in two events will choose incorrectly; this seems to be based on, among other factors, a lack of background knowledge regarding the two situations and perceptions formed on the basis of media reports.

As examples of this phenomenon we will choose

It must be emphasized that no activity is totally risk free, but many Americans seem to believe that the only acceptable alternative is one involving zero risk. This is impossible to achieve, and reflects an increasingly prevalent "Disneyland" mentality that is causing a great deal of harm to our society as a whole.

Drugs and Safety

Our first area of inquiry involves prescription drugs currently on the market. News reports involving products such as Celebrex and Vioxx have generated a storm of controversy regarding the safety of these and other drugs, and have fueled the arguments of "natural remedy" proponents whose own motives and conclusions are often questionable, if not flatly biased. However, most media outlets either mis-reported the clinical results or released biased stories that inflated the apparent risk level involved in using the drug.

The FDA's statement tells the whole story, noting that other studies showed no risk of increased CV problems. It is also the case that the study showing increased CV risk involved cancer patients; one unanswered question is whether another aspect of the cancer treatment regimen (or perhaps the cancer itself) predisposed patients involved in the trial to increased CV issues. Did Celebrex actually cause the reported 2.5x increase in CV hazard, or is some unknown factor involved? Did the selection criteria for patients involved in the study create a group naturally predisposed to a Celebrex side-effect? All these questions must be answered before the drug is abandoned or forced from the shelves.

From a risk analysis viewpoint, we must attempt to calculate the hazard involved in use of the drug vs. its potential benefit. This is true of all drugs, including those of allegedly "natural" origin since any chemical substance has the potential to cause an adverse effect in a given individual, and one must even weigh the risk of taking an aspirin to end a headache that would resolve itself without treatment over time.

Taking the aspirin involves low risk unless the patient has (for example) a history of gastric bleeding or other blood clotting problems, and failure to use a drug to end the headache is (where a normal tension or sinus headache is involved) also a low risk action. In this case, the patient may choose either course of action without much fear of unfortunate consequences. The headache, while inconvenient, may simply take longer to resolve itself if no anti-inflammatory drugs are used.

Similarly, failure to take Celebrex (also a pain control medication) for arthritic pain may involve a low risk if symptoms are unlikely to increase, but sufferers of chronic pain may choose to take the medication since the long term effects of such pain often involve depression, loss of sleep, and other life-altering factors. Such factors may, over time, cause an elevated risk to the individual due to fatigue, psychological problems, or other effects of long-term pain on the body and psyche. Thus the patient, with medical guidance based on other risk factors, must choose whether or not to take the medication.

Conversely, a person diagnosed with terminal cancer may be advised to undergo radiation therapy or make use of medications that involve a high risk of side effects. This person must also make a decision, since failure to use the recommended medication may also result in death. The decision must be made: face a high risk of certain death due to the cancer's effects, or elect to undergo treatment based on an understanding of the risks involved. If the patient is very old and the cancer is of a long-acting variety (prostate cancer, for instance, may take many years to cause death or significant illness) then perhaps treatment can be avoided since the patient is likely to die of other causes before the cancer acts. But a young person afflicted with fast-acting bone cancer risks nothing by electing to undergo treatment; the choice in this case may be between a rapid and painful death or, if treatment is successful, an extended and useful life span.

If one in one thousand (1:1,000) survive a given illness without treatment, but one hundred in one thousand (100:1,000) survive with treatment, then the risk of treatment is worthwhile.

Immunizations: Dangerous?

Much has been made in the media regarding the presence of a mercury-based compound in some vaccines designed to prevent childhood illnesses. Some groups, including natural-medicine advocates and overly zealous parents, have even advocated the cessation of vaccination programs on the basis of the alleged risk involved. This is a gross over-reaction to an extremely minor and debatable problem; no controlled studies have proven a link between the mercuric compound (a preservative) and the autism often claimed to have resulted in a very limited number of children. While any instance of a side effect causing death or disability in a given individual is tragic, the rate at which such effects are encountered must also be considered.

For instance: the polio virus causes "fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralysed, 5%–10% die when their breathing muscles become immobilized" [italics mine].

That's one in two hundred (1:200).

Vaccination, however, according to the Sabin Vaccine Institute produces a one in three million chance of paralysis.

That's one in three million (1:3,000,000).

Compute the risk: 15,000x more risk is involved when an individual remains unvaccinated.

Claims have been made that the MMR (Measles, Mumps, Rubella) vaccine causes autism, asthma, and other side effects. But again, the risk of not vaccinating a child far outweigh those of permitting the vaccination to occur. The National Health Services in the UK publish statistics showing this very clearly:

children suffering from measles-related convulsions:

without vaccine: 1:200

with 1st dose of vaccine: 1:1000

children suffering from measles-related meningitis or encephalitis:

without vaccine: 1:200 to 1:5000

with 1st dose of vaccine: less than 1:1,000,000

Likewise, only one study in 1998 showed any possible link between the MMR vaccine and autism, and all other alleged links to other side effects (Crohn's Disease and asthma) are also unproven by any study. All other "proofs" of such a link consist only of unproven cause-and-effect claims made by parents; these are cases of the post hoc, ergo propter hoc or "after this, therefore because of this" fallacy that attempts to link an earlier event with a later result. All such cases are purely anecdotal, no matter what advocates of "natural" medicine may say.

Driving vs. Flying

Recently, a relative was asked which was more dangerous: flying in a commercial airplane or driving a car. Unsurprisingly, it was claimed that flying was more dangerous. This illusion seems largely based on media reports of airline accidents and the horrific images displayed for days afterward by the same media outlets, and it is also incorrect. The risks are simple to analyze since data are available from various agencies detailing the number of fatal accidents involving various modes of transportation for a given year. The numbers for 2001 (the most recent available when this article was written) show the difference quite clearly:

Cause of Death 2001 Deaths One Year Odds Lifetime Odds
Car occupant 14,946 19,075 247
Air and space transport 918 310,560 4,023

Note that 2001's data included deaths resulting from the 9/11 terror attacks, so the figures for that year may be somewhat inflated in relation to other years.

From the above, the odds of dying in a car crash in 2001 were 1:19,075, whereas those of going to one's reward as a result of an airline disaster were only 1:310,560. This means that driving an automobile on a given day is sixteen times riskier, in the pure sense of the word, than flying on an airliner. Again, the "common sense" method of risk analysis is simply wrong based on real-world data. This may be of little consolation to someone who loses a relative or friend in an airline accident, but the numbers don't lie.


Auto manufacturers and airline operators must be held accountable for safety issues, it's true. Likewise, drug companies must adhere to safety standards and should be held accountable for proven defects in their evaluation procedures, as should all manufacturers of goods sold to the public (though medical groups should also be held to higher standards due to the nature of their business). However, the public must also take responsibility for analyzing and understanding risk and its effect on their daily lives; the current environment of litigation and paranoid insistance on perfection reflects a desire among our society to achieve a utopian ideal of perfection.

Risk can be avoided (by avoiding an activity or situation), mitigated (by isolating and eliminating controllable elements), or reassigned (by buying insurance), but it cannot be eliminated.

If risk is not permissible, our society will never progress.

Note: All information contained in these pages is © 2004 Richard E. Joltes. Excerpts may be used where proper credit is given and permission is obtained in advance. All rights reserved.