Media Attention and Risk Perception

From a Freaknomics interview of author Ben Sherwood:

Can a positive outcome to a crash like USAir 1549 change often unrealistic public perceptions of the fatality of plane crashes?

I doubt it. It’s incredibly safe to fly — your chances of dying on your next domestic flight are just one in 60 million — but many Americans are still petrified of air travel.

It’s no surprise: Plane crashes monopolize media coverage. Indeed, one MIT study found that airplane crash coverage on the front page of The New York Times was 60 times greater than reporting on HIV/AIDS per 1,000 deaths; 1,500 times greater than reporting on auto hazards; and 6,000 times greater than cancer.

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Now, the key to this passage is they only looked at the front page. Still, it's very interesting and telling on why our perceived risks rarely match the actual risks.

How Do Men Die in the Prime of their Lives?

My friends and I are reaching a milestone soon - a quarter century lived. Our own deaths are probably very far from our minds, and for good reason: about 2 percent of male deaths come from the 25-34 category. So while small, it is not insignificant and worth looking at.

According to the CDC in 2004 - the following are the top ten causes of death for males in the United States between the ages of 25-34.

1. Unintentional Injury - 34.8%
2. Suicide - 14.6%
3. Homicide - 13.3%
4. Heart Disease - 7.6%
5. Cancer - 6.2%
6. HIV Disease - 3.2%
7. Diabetes - 1.2 %
8. Stroke - 1.0%
9. Birth Defects - 0.8%
10. Chronic Liver Disease - 0.8%

Unsurprisingly, most of the deaths are not related to traditional disease: accidents (probably mostly automobile), suicide, and murder. This possibly suggests the need for better mental health counseling, which is an area I know very little about - including it's effectiveness and differences between nations.

What surprised me the most in these numbers is the rate of heart disease. Every year a couple of thousand in this young age group are dying of heart disease. I'm interested to know who these people are. Do they have some genetic defect that makes them especially vulnerable? Do they smoke a lot? Are they morbidly obese?

I'll break down the cancer rates in a later post, but younger males should look for cancer in the testis, the blood cancers (lymphoma), and skin cancer (melanoma).

When broadening to include females and between 25-44...

Causes of Death	Number of Deaths	Rate per 100,000
25-44 years All causes	148,904	177.8
1 Accidents and adverse effects	26,554	31.7
. . . Motor vehicle accidents	14,528	17.3
. . . All other accidents and adverse effects	12,026	14.4
2 Human immunodeficiency virus infection	22,795	27.2
3 Malignant neoplasms, including neoplasms of lymphatic and hematopoietic tissues	22,147	26.4
4 Diseases of heart	16,261	19.4
5 Suicide	12,536	15
6 Homicide and legal intervention	9,261	11.1
7 Chronic liver disease and cirrhosis	4,230	5.1
8 Cerebrovascular diseases	3,418	4.1
9 Diabetes mellitus	2,520	3
10 Pneumonia and influenza	1,972	2.4
. . . All other causes (Residual)	27,210	32.5

You can notice the homicide and suicide rates are down, while Cancer and HIV increase. However this data is a bit older (1996), so the HIV mortality rate has gone down in recent years.

Women Concentrate on the Wrong Organ (too)

Fear is an interesting concept that I hope to explore more in the future.

In a 2005 study by Women's Health Research, over 1000 women were asked - which disease they feared the most. I was rather surprised they found the fear of Breast Cancer more than doubled Heart Disease. While Breast Cancer caused approximately 3% of the US deaths in 2005, over 22 percent have the most fear for the disease. On the other hand, heart disease accounts for 28.6 percent of diseases and only 9.7 percent consider their top fear!! I know the US society has placed a higher emphasis of breasts over heart, but I can't say I expected this.

Fear Rank																					Disease	Women's Most Feared Diseases										Cause of Death in Women					Difference
1																					Cancer (unspecified)	24.00%										21.60%					2.40%
2																					Breast Cancer	22.10%										3.24%					18.86%
3																					Heart Disease	9.70%										28.60%					-18.90%
4																					HIV/AIDS	9.30%										2%					7.30%
5																					Alzheimer’s Disease	4.60%										3.40%					1.20%
6																					Ovarian Cancer	2.70%										1.30%					1.40%
7																					Lung Cancer	2.40%										5.62%					-3.22%
8																					Diabetes	2.40%										3.10%					-0.70%
9																					Colon Cancer	1.60%										1.94%					-0.34%
10																					Stroke	1.20%										8.00%					-6.80%

So what are the possible explanations for this?

High Incidence?
-While the mortality of breast cancer is low, there is a significant amount of women living and bravely battling the disease. On the other hand, the same can be said about heart disease.

Feeling of Control
-While risk factors such as diet, obesity, and hormones have been established, the cause for breast cancer can still be considered quite a mystery. So most women likely believe that she could develop BC and don't have the power to control it. The risk factors for heart disease - (diet, physical activity, smoking) are a bit more established, so women's feeling of control may be stronger for CHD.

Public Exposure
-Another explanation is that breast cancer has had stronger activists, fundraisers, and lobbyists that push the disease into the mainstream. The general wisdom may be that since Breast Cancer is getting the same or more ad time than Heart Disease - women's risk of death are great for BC.

*Edit*
Age of Disease
Women may believe that they are more likely to get Breast Cancer at a younger age than Heart Disease. According to SEER the median age of dianosis is 61, while the median age of death is 69. For heart disease the average age of a first heart attack is around 70 years old (though the disease can be caught at a much earlier stage).

Women still believe it's a male disease
The stereotypical person with heart disease (at least in my mind) is an overweight, red faced guy in a suit. Women only comprise of about 25 percent of heart studies, and things like this need to change.

Conclusion:
Heart disease kills about 8 times the women than Breast Cancer. The medical community needs to do a better job about expressing this risk. Maybe when people go to their primary doc, they should be asked this "what disease do you fear the most" question. Then the education can begin. Another idea is instead of counseling by doctor, people should have a "medical counclier" who discuss peoples risk of disease and what they can do for prevention. According to the Women's Heart fact sheet only 2 percent of the NIH budget is spent on prevention, and that is just flat out wrong .

2005 data from:
CDC
Women's Health Research
Women's Heart Fact Sheet

US Trend in Tobacco Use and Lung Cancer Mortality

A question was proposed in the comments of the previous entry - how has smoking rate changed after the GIs had been given cigarettes in their rations during World War 2 (early 1940s).

The following graphic displays this trend well. It also shows the lag in time of tobacco use to lung cancer mortality. It's nice to see both the cigarrette consumption and lung cancer mortality decreasing, but sadly this is not true in developing asian and african countries where ciagrette use is becoming very common.

Source: ACS 2008 Cancer Statistics Presentation

The graphic below displays the amount of different cancer deaths that can be attributed to smoking. Lung cancer greatly outranks the rest of the cancers, with an attribute rate of 80-90 percent. However only 20 percent or so of smokers end up with lung cancer, due to other risk factors such as genetics, amount smoked, etc.

Source: ACS Cancer Facts and Figures

Top Cancers in the United States

Here are the most popular figures in general cancer epidemiology - a flavor of things to come for this blog. Please share ideas on what to show in the future.

Notice how deadly Lung, Pancreas , and Leukemia - comparing their incidence and mortality rates. It's interesting how little you hear about Pancreas, Ovary, etc - it's probably because the 5 years survival is so low that there is much less pressure to lobby for these diseases. Overall Men have a 1 in 2 chance of developing cancer in their lifetime, while Women have a 1 in 3 chance.

The jump in prostate cancer in the early 90s is due the PSA screening coming into the mainstream. PSA screening is still controversial today - it has not been proven to extend/save lives as of yet. With prostate cancer's five year survival rate of 99 percent, epidemiologists are asking: should we put putting men through this?

Male death rates over time - notice how lung how over-trumped them all due to tobacco use. The disappearance of stomach cancer is still a bit mysterious.


Lung cancer has recently become the number 1 killer for females, due to a later development of tobacco use. Breast and colon cancer, which diet is a major risk factor, are well ahead of the rest of the cancers

Cell Phones and Brain Cancer

Figure 1. Estimation of the penetration of electromagnetic radiation from a cell phone based on age (Frequency GSM 900 Mhz) (On the right, a scale showing the Specific Absorption Rate at different depths, in W/kg) [ ]
Today I saw Devra Davis lecture about her new book, The Secret History of the War on Cancer. In the book she discusses the controversial topic of Cell Phones and Brain Cancer comparing it to the Tobacco/Lung Cancer relationship back in the 50s.

Her main points were:
-We don't have enough evidence to make conclusions one way or another
-Previous studies (which mostly have shown no association) have been biased, cell phone users included anyone who made in a call in the past 6 months
-Huge increase in use has only happened in past ten years, cancer takes 20-30 years to develop.
-Particularly concerned about children's increased use of cell phones, since skulls are thinner and brains aren't not fully myelinated. (see above figure)
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This NY Times article provides a more balanced view:

"According to the Food and Drug Administration, three large epidemiology studies since 2000 have shown no harmful effects. CTIA — the Wireless Association, the leading industry trade group, said in a statement, “The overwhelming majority of studies that have been published in scientific journals around the globe show that wireless phones do not pose a health risk."

The F.D.A. notes, however, that the average period of phone use in the studies it cites was about three years, so the research doesn’t answer questions about long-term exposures. Critics say many studies are flawed for that reason, and also because they do not distinguish between casual and heavy use.

Cellphones emit non-ionizing radiation, waves of energy that are too weak to break chemical bonds or to set off the DNA damage known to cause cancer. There is no known biological mechanism to explain how non-ionizing radiation might lead to cancer."
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Studies that have shown risk have unalarming low Odds Ratios:

Meta-analysis of long-term mobile phone use and the association with brain tumours

Abstract:
We evaluated long-term use of mobile phones and the risk for brain tumours in case-control studies published so far on this issue. We identified ten studies on glioma and meta-analysis yielded OR = 0.9, 95% CI = 0.8-1.1. Latency period of ≥10-years gave OR = 1.2, 95% CI = 0.8-1.9 based on six studies, for ipsilateral use (same side as tumour) OR = 2.0, 95% CI = 1.2-3.4 (four studies), but contralateral use did not increase the risk significantly, OR = 1.1, 95% CI = 0.6-2.0. Meta-analysis of nine studies on acoustic neuroma gave OR = 0.9, 95% CI = 0.7-1.1 increasing to OR = 1.3, 95% CI = 0.6-2.8 using ≥10-years latency period (four studies). Ipsilateral use gave OR = 2.4, 95% CI = 1.1-5.3 and contra-lateral OR = 1.2, 95% CI = 0.7-2.2 in the ≥10-years latency period group (three studies). Seven studies gave results for meningioma yielding overall OR = 0.8, 95% CI = 0.7-0.99. Using ≥10-years latency period OR = 1.3, 95% CI = 0.9-1.8 was calculated (four studies) increasing to OR = 1.7, 95% CI = 0.99-3.1 for ipsilateral use and OR = 1.0, 95% CI = 0.3-3.1 for contralateral use (two studies). We conclude that this meta-analysis gave a consistent pattern of an association between mobile phone use and ipsilateral glioma and acoustic neuroma using ≥10-years latency period.
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My Conclusions:
1. Chances are there is little or no risk increase for general population, but even a small risk increase would be a big public health problem since billions of people use cell phones.
2. The lack of known biological mechanism is huge and the major reason the FDA and scientists aren't freaking out
3. Studies should be particularly concentrated on children
4. Time will tell, hopefully we can gather more evidence and not be slow to action like with tobacco (if there happens to be causational evidence).
5. If worse comes to worse, we can always go back to the Banana Phone...