INS and diabetes mellitus: Univariate weighted logistic regression and weighted multivariate logistic regression with adjustment for covariates (Models 1-3) were used to explore the risk of DR occurrence across different DM durations, as well as the synergistic effect of DM duration and anemia on DR occurrence.<h4>Results</h4>Weighted univariate logistic regression analysis revealed that insulin use, diabetic nephropathy (DN), and education level were significantly associated with DR across both DM duration groups.