Table 6.
Odds of death on 8000 m peaks estimated from a multivariate logistic regression model, by climb characteristics
| Variable | Odds ratio (95% CI)* | P† |
|---|---|---|
| Expedition number‡ | 1.00 (0.96 to 1.05) | 0.904 |
| Commercial status | 0.100 | |
| Traditional | 1.00 | |
| Commercial | 0.63 (0.37 to 1.09) | |
| Route | 0.142 | |
| Non-standard | 1.00 | |
| Standard | 0.74 (0.49 to 1.11) | |
| Peak | <0.001 | |
| Annapurna I | 1.00 | |
| Cho Oyu | 0.17 (0.08 to 0.36) | |
| Dhaulagiri I | 0.73 (0.37 to 1.44) | |
| Everest | 0.42 (0.25 to 0.73) | |
| Kangchenjunga | 0.55 (0.24 to 1.22) | |
| Lhotse | 0.42 (0.18 to 1.00) | |
| Makalu | 0.43 (0.20 to 0.90) | |
| Manaslu | 0.84 (0.43 to 1.64) | |
| Age of climber (decade of life) | 1.01 (0.99 to1.03) | 0.279 |
| Season | 0.910 | |
| Spring | 1.00 | |
| Summer | 0.36 (0.02 to 6.00) | |
| Autumn | 0.98 (0.66 to 1.44) | |
| Winter | 1.05 (0.48 to 2.28) | |
| Sex of climber | 0.995 | |
| Male | 1.00 | |
| Female | 1.00 (0.56 to 1.79) | |
| Summit success | 0.036 | |
| No | 1.00 | |
| Yes | 1.50 (1.03 to 2.19) | |
| Year of expedition | 0.98 (0.96 to 0.99) | 0.011 |
*Standard errors adjusted for clustering on two population averaged models, using method described by Miglioretti and Heagerty.23,24
†Represents an omnibus hypothesis for each individual variable.
‡Credit given for all climbs to constituent peaks, including those with altitude <8000 m.