Alert to senior climbers: Beware of dangerous Everest study

Posted: Aug 16, 2007 05:55 am EDT

A dangerous study is spreading like a wildfire in global news right now. Its conclusion, "On Everest, youth and vigor trump age and experience."

The study is based on a total of three (!) 60+ climbers, dying on Everest since 1922. Parts of the study claims there's a 25% risk of dying after Everest summit for people over 60 years old. That number is based on two climbers, out of 10,000 attempts.

A basic lesson in small sample sizes

Well how about the following stats: Also two 70+ years old have in fact summited Everest. Both survived. That's age and experience over the youth and vigor of the 60 years old. Or?

This is a classic example of what scientific magazines and Universities classify as one of three most common mistakes in statistical evaluation - namely too small sample size.

Why is that? On K2 - some very difficult lines show rates of 2-4 summits vs. O deaths. Using the methods of the Everest study, this would mean that climbs on for example the West Ridge/SW side are 100% safe: An outrageous and dangerous conclusion, explaining why "small samples" can't be used in statistics.

The Everest study actually admits that, albeit in a very small byline: "However, since only 60 climbers were sexagenarians and only three of them died, an increased overall death rate for sexagenarians is tentative" (p2).

And then the remarkable conclusions arrive.

Analyzing cause of death

As far as we know today, there is no age-related elevated danger for climbers above 60 to go climbing high peaks, which correlates with several studies such as one made by Kinoshita in 2000 for GII.
Kinoshita study

Out of 207 deaths on Everest since 1922, only 3 climbers were 60+. A 4th was 63 but perished below BC. Only when fatalities on Everest reach above 10-20 cases for a certain group, will we have a fair base to analyze data and receive any statistical significance.

Based on a small selection of only three people, the only relevant method of analyze is to check the cause of death in each case. This is difficult as two of the bodies are still up on Everest and there is no coroners report, yet at present, there's no indication that either of the climbers died of age related reasons.

Conclusion from Everest statistics: Academics - Stay home!

So let's check what happened:

In 1993, US NASA astronaut Karl Gordon Henize, 63, died of AMS at 6000 meters. Dr. Henize was a mission specialist on STS-51-F in 1985 (at 59). He did 126 orbits of the earth. He went to the North side standard route with commercial expedition leader John Tinker (OTT Expeditions). On the second day after reaching ABC, he developed acute HAPE and died. Last year, a London Judge dismissed a (suspected oxygen based) negligence case against OTT expeditions related to the death of a young Briton. There is no reason to believe that age was a factor in the death of Dr. Henize, who was buried near Everest.

In 2004, well known Washington DC Pathologist Nils Antezana, 69, died after he was left (alive) at 8650 meter on Everest South Side by his personal, but highly ill-reputed mountain guide Gustavo Lisi on descent from summit. The incident was examined by Washington Post and other media, including ExplorersWeb. Reason for his death is unclear, but insufficient oxygen supply is a likely factor. No age related problems were reported, however Antezana's body remains on Everest.

Also in 2004, Japanese female Physician Shoko Ota, 63, died in a fall after summiting Everest on May 20. The fixed rope snapped. A second version of the event indicates that lack of supplementary oxygen was a factor, causing Ota unable to move and lose consciousness on descent. Dr. Ota was a member of a guided expedition by Japanese based Adventure Guides. There seems to be no age factor related to her death and she remains on Everest.

In 2005, Canadian Professor of human kinetics (health) and Doctor of Sports Psychology Sean Egan, 63, died at 4600 meters (below BC - thus technically not on Everest). Sean suffered several health problems from the very beginning of the expedition. During an acclimatization trip, Sean felt ill (respiratory problems) and was not capable of reaching Camp 2. He returned to BC and, along with his Sherpa, continued down the valley for thicker air and medical treatment. During the trek to the hospital in Periche, he suffered a cardiac arrest and died on April 29. It is unknown if Dr. Egan's death was related to altitude or age.

BaseCampMD: Those over 60 had half the incidence of AMS

So did the seniors die of age, negligence - or just the regular high altitude risks that killed 200 of their juniors? There have been many complaints on Everest about guides pushing clients too hard, and providing insufficient oxygen. A study of all age groups would be needed to leave a clue on what actually killed the four above.

Regarding the isolated question of age though; ExWeb checked in with the perhaps most seasoned Everest physician out there today, BaseCampMD's Luanne Freer. "Age does have an influence on incidence of altitude, with those over 50 years old somewhat less vulnerable," she said.

"In a large Colorado study, those over 60 had half the incidence of AMS as those less than 60 years of age. In contrast, a study of 827 mountaineers in Europe showed no influence of age on susceptibility. I am aware of no study that has ever shown the older to be more susceptible." (Check below for some of Luanne's references).

Luanne also said that while "cardiac disease and other chronic illnesses are more prevalent with increasing age; these conditions may or may not be impacted by altitude stress,"
she saw no evidence that the deaths of Egan or Antezana (climbing Everest south side where BaseCampMD operates) were age related.

"I remember being completely inspired and amazed last year when two Japanese women (74 years old) got up to the south Col," the Everest Doc closed our brief interview.

K2 West Face grandfathers still alive

A larger sample of seniors can be obtained when examining all Himalaya climbers. One prime example is the current highly difficult K2 West Face expedition, where - only last month - several of the Russian climbers became grandfathers somewhere between camp 3 and 4.

The youngest of the expedition mountaineers was born in 1973, the oldest in 1946. Two climbers have been evacuated - both due to altitude induced thrombosis - and both among the youngest: Vitaly Ivanov born in 1963, and Alex Korobkov born in1971!

Researcher: Some of my colleagues like fame

ExWeb also checked the study with a chief scientist (Lithium hybrids) Eva Ronnebro, CA. "Oh, researchers always want to make a name for themselves in media," she laughed. "3 samples? Even 10 is much too low - we like to work with at least 20."

ExWeb founder, Tom Sjogren, further commented, "If I had used a sample of only three cases for Statistical evaluation at the Stockholm School of Economics, my Professor would have flunked me."

The facts

Active seniors often have a hard time defending their lifestyle - especially with the more sedentary in their own age group. False conclusions made by studies like the one currently reprinted by the world media doesn't help. So let's check the real facts, based on large enough age groups:

The stats for 4 age groups on Everest are as follows:

0-29: 2420 climbers, 906 summits, success rate 37.44%, fatalities 45, Attempt vs. Fatality rate: 1.86%
30-39: 4095 climbers, 1338 summits, success rate 32.67%, fatalities 68, Attempt vs Fatality rate: 1.66%
40-49: 2111 climbers, 559 summits, success rate 26.48%, fatalities 31, Attempt vs. Fatality rate: 1.47%
50-74: 1005 climbers, 136 summits, success rate 13.53%, fatalities16, Attempt vs. Fatality rate: 1.59%

This shows what all mountaineers always knew: Young climbers are bold climbers, and die too soon. On Everest, as in other exploration, age and experience trump youth and vigor.

Even the Space folks have noticed: The first Soviet Cosmonaut team was in their mid-twenties. The first Americans averaged just over 30 years. The present Shuttle Mission (STS-118) crew is averaging 47 years. Mike Melville (Spaceship One pilot) was born in 1941. Brian Binnie in 1953. And let's not even go to exploration in polar areas and on the oceans.

Staying home

It ain't over until it's over. An active lifestyle will make you younger and healthier. Let's close with a quick look at the risk of staying home:

15-24 0.1%
25-34 0.1%
35-44 0.2%
45-54 0.4%
55-64 1.1%
65-74 2.5%

The general increase in death rate is 25 times higher for people in their sixties than for people in their twenties. Not so on Everest, where older climbers attempting the peak actually have a less relative risk of dying than young climbers.

The general attempt/fatality risk on Everest is 1-2%. While a 30 years old runs an 80 time higher risk to die on Everest compared to if he stayed home; the risk increases only 3 times for the 60+ years old. Based on all human experience (and proper statistics), the message to senior mountaineers can only be one: Keep climbing!

Recent Everest age study ($30)

Everest age details on AdventureStats (free)

*One of the world's most foremost experts on AMS is Dr. Peter Hackett. He worked for NOVA "Everest the death zone" 1997.

Acute Mountain Sickness
As seen in the New England Journal of Medicine, July 12, 2001
By Peter Hackett, MD and Robert C. Roach, PhD:

1991 Colorado survey study: Acute Mountain Sickness (AMS) in 22% at 7,000-9,000; 42% at 10,000. Risk factors include previous bouts of AMS, residence below 2,800, exertion and preexisting cardiopulmonary conditions. Persons over 50 years of age are somewhat less susceptible to AMS whereas children are about as susceptible as adults.

Women are less susceptible than men to HAPE (High Altitude Pulmonary Edema) but equally prone to AMS. Physical fitness is not protective against high-altitude sickness. Genetic factors and environment probably explain varying individual susceptibilities.

Descent of 1,500 to 3,000 usually leads to resolution of AMS; HACE (High Altitude Cerebral Edema) may require greater descent. New evidence suggests that ALL people have swelling of the brain at high altitudes. One hypothesis is that those with high cerebrospinal fluid volume to brain volume experience AMS less often, since they have more skull space with which to accommodate brain swelling. 400 to 600 mg. of ibuprofen decreased or resolved high-altitude headaches.

Gradual ascent is still the best strategy for AMS avoidance. In two controlled trials, Ginkgo Biloba (80-120mg. orally twice a day) prevented AMS during ascent to 15,000 and was 50% effective in an abrupt ascent to 12,500. Prophylactic aspirin (325mg. every four hours totaling three doses) reduced the incidence of headache from 50 to 7%. The notion that over hydration prevents AMS has no scientific basis. PETER HACKETT, MD: Associate Professor, University of Washington School of Medicine; Director, Denali Altitude Research Project, Medical Control, Denali National Park Mountaineering Rangers; Emergency Medicine, Grand Junction, Colorado

Other references:
Roach RC, Houston CS, Honigman B, et al. How well do older persons tolerate moderate altitude? West J Med 162: 32-36, 1995.

Schneider M, Bernasch D, Weymann J, et al. Acute mountain sickness: influence of susceptibility, preexposure, and ascent rate. Med Sci Sports Exerc 34: 1886-1891, 2002.

Ages of K2 West Face climbers, courtesy of RussianClimb:

Gleb Sokolov 1953
Vitaly Ivanov 1963
Vitaly Gorelik 1967
Eugeny Vinogradsky 1946
Alex Bolotov 1963
Nick Totmjanin 1958
Gennady Kirievsky 1961
Alex Korobkov 1971

Serguey Penzov 1950
Victor Volodin 1962
Valery Shamalo 1965
Dmitry Komarov 1973
Pavel Shabalin 1961
Iljas TUkhvatullin 1958
Andrew Mariev 1971

#Mountaineering #Mountaineering #Polar #Space #Oceans #Medical #Stats #classic

Truth #10: Age is not a significant factor when it comes to fatalities or success on Everest. The truth about great human adventure feats is seldom found in glossy coffee table books. At 65 years old, Pavel Rezvoy became the oldest rower in the history of ocean rowing - arriving Barbados only 2,5 days after the 23 years old winner. Pavel is just one example that real exploration knows no limits - including age. Image courtesy of the OceanrowingSociety.
On K2 West Face two climbers have been evacuated - both due to altitude induced thrombosis - and both among the youngest: Vitaly Ivanov was born in 1963...
...and Alex Korobkov was born in 1971! (Both images courtesy of RussianClimb)
Things are much more simple than people make them out to be. We seem to be experts at complicating things, Nils told his kids. Image of Nils on the summit of Illimani, courtesy of Fabiola Antezana.
AdventureStats clearly shows (without charge) that there is no correlation between age and fatalities on Everest. Check the link at the end of the story. (Click to enlarge)
"Miura could be considered to be the first speedriding pilot in the world!" says Mal about the Japanese Everest record climber, still going strong.

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