Triage assessment of cardiorespiratory risk status based on measurement of the anaerobic threshold, and estimation by patient-reported activity limitation

Saranya Thurairatnam; Filip Gawecki; Timothy Strangeways; Joseph Perks; Vatshalan Santhirapala; Jonathan Myers; Hannah C Tighe; Luke SGE Howard; Claire L Shovlin

Anaemia is very common, and readily correctable in clinical practice. We modelled whether increasing 198 haemoglobin alone might allow patients to move from a high to lower risk category. In multivariate 199 regression analysis, haemoglobin explained 57.3% of the variance in log-transformed AT (adjusted R 2 200 0.57). The regression coefficient of 0.053 (95% confidence interval 0.005, 0.100, p=0.031) implied that 201 for each 1 g.dL -1 (10 g./L -1 ) rise in haemoglobin, the AT would rise by 0.76 ml.min -1 .kg -1 , and a 202 haemoglobin rise of 2.5 g.dL -1 would increase AT by 1.9 ml.min -1 .kg -1 , moving 7 (63.6%) of patients 203 from high to low risk. In the existing dataset, it was not possible to preselect all patients who would 204 benefit using single resting demographics (data not shown).