Table 3.

Effect modification of DM duration on the relationship between BUN and the probability of DR in different models.

	N	OR (95%CI) P-value	P for interaction
Crude model
BUN ‡ DM duration < 10 years	208	1.31 (1.13, 1.52) 0.001	0.031
BUN ‡ DM duration ≥ 10 years	216	1.10 (1.02, 1.18) 0.013
Minimally adjusted model
BUN ‡ DM duration < 10 years	206	1.43 (1.21, 1.69) < 0.001	0.009
BUN ‡ DM duration ≥ 10 years	216	1.13 (1.05, 1.22) 0.002
Fully adjusted model
BUN ‡ DM duration < 10 years	198	1.31 (1.10, 1.57) 0.003	0.048
BUN ‡ DM duration ≥ 10 years	206	1.09 (1.00, 1.19) 0.051

Crude model: we did not adjust other covariants.

Minimally adjusted model: we adjusted age and sex.

Fully adjusted model: we adjusted age, sex, D-dimer, LDL, HbA1c, Serum albumin, HBP, SBP.