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Do Oscar Winners Live Longer?

If you put "Oscar winners live longer" in Google you will get over 7,000 hits. Here is one from the January 23, 2007 issue of Health and Aging

Oscar winners live longer: Reported by Susan Aldridge, PhD, medical journalist.

It is Oscar season again and, if you're a film fan, you'll be following proceedings with interest. But did you know there is a health benefit to winning an Oscar? Doctors at Harvard Medical School say that a study of actors and actresses shows that winners live, on average, for four years more than losers. And winning directors live longer than non-winners. Source: "Harvard Health Letter" March 2006.

The assertion that Oscar winners live longer was based on an article by Donald Redelmeier, and Sheldon Singh: "Survival in Academy Award-winning actors and actresses". Annals of Internal medicine, 15 May, 2001, Vol. 134, No. 10, 955-962.

This is the kind of study the media loves to report and medical journals enjoy the publicity they get. Another such claim, in the news as this is written, is that the outcome of the Super Bowl football game determines whether the stock market will go up or down this year. Unlike the Oscar winners story the author of this claim, Leonard Koppet, admited that it was all a joke, see Chance News 13.04.

A recent paper by James Hanley, Marie-Pierre Sylvestre and Ella Huszti, "Do Oscar winners live longer than less successful peers? A reanalysis of the evidence," Annals of Internal medicine, 5 September 2006, Vol 145, No. 5, 361-363, claims that the Redelmeier, Singh paper was flawed. They provided a reanalysis of the data showing that it does not support the claim that Oscar winners live longer.

For their study, Redelmeier and Singh identified all actors and actresses ever nominated for an academy award in a leading or a supporting role up to the time of the study (n = 762). Among these there were 235 Oscar winners. For each nominee another cast member of the same sex who was in the same film and was born in the same era was identified (n= 887) and these were used as controls.

The authors used the Kaplan-Meier method to provide a life table for the Oscar winners and the control group. A life table estimates for each x the probability of living x years. In Chance News 10.06 We illustrated the Kaplan-Meier method, using data obtained from Dr. Radelmeier.

In their paper Redelmeier and Singh provided the following graph showing the life tables of the two goups.

http://www.dartmouth.edu/~chance/forwiki/oscar.jpg

The areas under the two curves are estimates for the life expectance for the two groups. Using a test called the "log-rank test" they concluded that the overall difference in life expectancy was 3.9 years (79.7 vs. 75.8 years; P) = .003.

While the life tables look like standard life tables there is one big difference. We note that 100 percent of the Oscar winners live to be at least 30 years old. Of course this is not surprising because they are known to be Oscar winners. Thus we know ahead of time that the Oscar winners will live longer than a traditional life table would predict. This gives them an advantage in their life expectancy. This is called a selection bias. Of course the controls also have an advantage because we know that were in a movie at about the same age as a nominee. But there is no reason to believe that these advantages are the same.

Here is a more obvious example of selection bias discussed in Robert Abelson's book "Statistics as Principled Argument' and reported in Chance News 4.05.

A study found that the average life expectancy

of famous orchestral conductors was 73.4 years, significantly higher than the life expectancy for males, 68.5, at the time of the study. Jane Brody in her "New York Times" health column reported that this was thought to be due to arm exercise. J. D Caroll gave an alternative suggestion, remarking that it was reasonable to assume that a famous orchestra conductor was at least 32 years old. The life expectancy for a 32 year old male was 72 years making the 73.4

average not at all surprising.

To avoid the possible of selective bias, Redelmeier and Singh did an analysis using time-dependent covariates, in which winners were counted as controls until the time of first they won the Oscar. This resulted in a difference in life expentance of 20% (CI, 0% to 35%). Since the confidence interval includes 0 the difference is not significant. So one might wonder why they made their claim that Oscar winners live longer.

In a letter to the editor in response to the study by Hanley et.al Sylvester et al study Redelmeier and Singh report that they did the same analysis with one more years data and obtained a result even more clearly not significant.

To avoid selection bias, Sylvester and colleagues analyzed the data by comparing the life expectancy of the winners from the moment they win with others alive at that age. In the McGill Press Release, Hanley remarks "The results are not as, shall we say, dramatic, but they're more accurate." We recommend reading this press release for more information about the study by Sylvester et al.

When the Redelmeier and Singh paper came out, our colleague Peter Doyle was skeptical of the results and suggested simple ways to to see that Oscar winners do not live longer. He described one of these methods as follows:

You can do a simulation to rewrite history, having the computer select at random new OSCAR winners from among each year's nominees. Each time you rewrite history you compute a new p-value, and you discover that you get a value less than .05 more than 5 percent of the time. You can do the same thing with data that are much more easily simulated, but still, it's kind of cool to have the computer churning out new OSCAR winners. Richard Burton would approve, because he generally comes out a winner!

Here is another way to see that Oscar winners do not live longer that Peter described in the form of a game of points:

We decide to compare those who have

won an Oscar (call them ‘winners’) with those who have merely been nominated (call them ‘also-rans’). Our ‘null hypothesis’ is that having won an Oscar doesn’t help your health. We create a contest by associating a point to the death of anyone who has ever been nominated for an Oscar. Points are bad: the winners get a point if the deceased was a star; the also-rans get a point if the deceased was an also-ran. Suppose that the deceased died in their dth day of life. Over the course of history, some number a of nominees will have made it to the kth. day of their lives, and been a winner on that day; some number b of nominees will have made it to the dth day of their lives, and been an also-ran on that day. If our hypothesis is correct, and having won an Oscar really doesn’t help your health, then the probability that the winners get this point should be a/(a+b). So now we’ve got a game of points. with known probability of winning for each point. If you carry out this analysis correctly, you will that the winners win very nearly the expected number of points, leaving us no reason to suppose that

winning an Oscar helps you live longer.

Despite the fact that, in their paper Redelmeier and Singh said the data they used would be available on their website, it never was. Thus Peter, with the help of a student Mark Mixer, had to determine their own data set which is available here in a Mathematica program that Peter wrote. If you do not have Mathematica you can read this using the free MathReader.

For the paper by Hanley and his colleagues, Redelmeier and Singh did make their data available but it still was not the original data since it included the results of one more year of Oscars winners. This data is available here.

Homework

Carry out one of Peter's methods using your favorite math program and either of the two data sets. Laurie's homework assigned by Peter was to do this using True Basic which is the only program he knows. He has not yet done his homework but do yours and report your findings in the next Chance News.