Variations with age
At the population level, for the leukocyte concentration, the best model was the model without age as explanatory variable, indicating that the leukocyte concentration did not vary with age (Table S2, 1A, Figure 1A). For the lymphocyte, neutrophil and eosinophil counts, the models with the quadratic age effect were better (Table S2). For the eosinophil counts, all the models with (linear and quadratic) and without age were competitive (Table S2). For the number of monocytes, the model with the linear age effect had the lowest AIC, but the model with the quadratic age effect was also probable (Table S2). The lymphocyte count decreased until 7 years old, followed by a slight increase at older ages (Figure 1B), conversely to neutrophil (Figure 1C) and eosinophil counts (Tables S2, 1A, Figure 1E). The monocyte count decreased with age (Tables S2, 1A, Figure 1D).