Abstract

Objective: To examine whether probabilities of success and of death of mountaineers on Mount Everest were a function of climber age or sex.

Setting: Climbing expeditions to Mount Everest, 1990-2005.

Participants: 2211 mountaineers (“members” only) who made their first attempt on Everest during the spring climbing season. Most were men (88.8%), few had prior experience on a Nepalese peak (38.1%), and all were between 15 and 69 years of age.

Main outcome measure: Probabilities of success (of reaching the summit or of reaching the summit and surviving), probabilities of death (anywhere above base camp, or on descent from the summit).

Results: Men outnumber women, but the percentage of women is increasing (10.3% for 2000-2005). The percentage of climbers older than 39 and of those older 59 has also increased over time (for 2000-2005, 45.6% and 3.6%, respectively). Men and women had very similar odds of summiting (30.9% vs. 28.3%) and of dying (overall: 1.6% vs. 1.6%; descent from summit: 2.3% vs. 4.3%). However, climbers older than 40 have progressively reduced odds of summiting, and climbers older than 60 have increased odds of dying, especially when descending from the summit. Sexagenarians had a roughly three times higher death rate overall than did younger climbers.

Conclusions: In this sample population, probabilities of success and of death are independent of the sex of the climber, but are influenced by age. However, success rates decline for climbers older than 39 and death rates increase for climbers older than 59.

The study may be accessed at Everest-BiologyLetters-Oct2007 [0.1kb Pdf]

Reference: Huey, R.B., Salisbury, R., Wang, J.-L., and Mao, M. 2007. Effects of age and gender on success and death of mountaineers on Mount Everest. Biology Letters 3:498-500