Effect of oxygen saturation on directional error.
Average predicted margins of directional error at peak velocity as a function of pulse oximetry (SpO2) at 760 m baseline and at 3100 m altitude for patients taking placebo and acetazolamide, respectively.Independent of block (post-sleep recall, immediate recall, 60° adaptation), for every increase in age by 1 year, the probability of a valid movement decreased by 1% (95%CI -2% to 0%, p = 0.003; 95%CI -2% to -1%, p < 0.001; 95%CI -2% to -1% p < 0.001 respectively). DE increased significantly with age (p = 0.005 for post-sleep recall, p = 0.008 for immediate recall, p = 0.001 for 60° adaptation).Females had a lower chance of performing a valid movement compared to men, with values ranging from 18% in immediate recall (95%CI 25% to 10%, p < 0.001) to 10% in 60° adaptation (95%CI 18% to 3%, p = 0.009) and 9% in post-sleep recall (95%CI 19% to 0%, p = 0.048). Sex did not have a significant effect on DE with a difference in treatment effect between males and females of 0.0° (95%CI -0.4° to 0.5°, p = 0.857) in post-sleep recall, 0.0° (95%CI -0.0° to 0.0°, p = 0.6621) in immediate recall and 0.0° (95% CI -0.0° to 0.0°, p = 0.298) in 60° adaptation.The study drugs were generally well tolerated and severe side effects did not occur. A detailed account on side effects in the main population of this trial has been published [