Fig. 1

Clinical consequences of applying threshold values from cohorts with mainly male participants to both sexes. This schematic graph presents the distribution of male and female physical fitness, as assessed using CPET parameters such as oxygen uptake at AT. Female distribution is shown on the left in yellow; male distribution is shown on the right in red. The threshold value at which patients are allocated to a “high-surgical-risk population” is based on the total pool of research participants. As shown in the graph, the proportion of females included in the high-risk category is much larger than the proportion of males because there are more males than females in the total study population. AT, anaerobic threshold; CPET, cardiopulmonary exercise testing