GSTM1 and chronic obstructive pulmonary disease: Multivariate Cox regression analysis demonstrated that baseline eGFR or CKD status were independent predictive factors of 28-day mortality after adjustments for multiple confounders (age, gender, history of diabetes, hypertension, heart failure, peripheral artery disease, coronary artery disease, COPD, statins, creatinine and Hb on admission) (Table 4).