ALB and diabetic kidney disease: (2) A series of sensitivity analyses were performed to assess the study’s robustness (target independent variable transformation, subgroup analysis, using a GAM to insert the continuity covariate into the equation as a curve, calculating E-values to investigate the possibility of unmeasured confounding, and reanalyzing the association between ALB and CKD progression after excluding participants with diabetic nephropathy or eGFR < 15 ml/min per 1.73 m2).