Fig. 2

Potential variables associated with hyponatremia in AECOPD patients were selected by LASSO regression model. A LASSO coefficients profiles for all variables. B Identification of the optimal penalization coefficient (λ) in the LASSO model, which was carried out by tenfold cross-validation by minimum criteria and 1-SE (standard error) criteria. Left line: the minimum error; Right line: the cross-validated error within 1 standard error of the minimum. C LASSO coefficient values of 9 potential variables