Non-linear relationship between age and subfoveal choroidal thickness in Chinese patients with proliferative diabetic retinopathy

Table 5 Results of stratified analysis between age and subfoveal choroidal thickness in patients with proliferative diabetic retinopathy

Y = SFCT, μm	n	β, 95%CI	P value
Gender
Female	99	-0.38 (-2.39 to 1.64)	0.7157
Male	135	-2.63 (-4.51 to -0.74)	0.0074
Hypertension history
No	126	-1.19 (-2.65 to 0.27)	0.1137
Yes	108	-3.27 (-5.42 to -1.12)	0.0037
Education level
Junior high school or below	147	-2.13 (-3.90 to -0.36)	0.0198
Senior high school	40	-0.72 (-4.44 to 3.00)	0.7086
College or above	44	-2.09 (-5.23 to 1.06)	0.2054
Diabetic nephropathy history
No	188	-1.76 (-3.06 to -0.46)	0.0089
Yes	46	-1.29 (-6.51 to 3.94)	0.6341
Stroke history
No	222	-1.48 (-2.80 to -0.16)	0.0294
Yes	12	Not applicable
Heart disease history
No	222	-1.61 (-2.90 to -0.32)	0.0153
Yes	12	Not applicable
Anemia history
No	162	-2.62 (-4.15 to -1.08)	0.0011
Yes	72	1.16 (-1.62 to 3.93)	0.4176
PRP
None	111	0.05 (-1.78 to 1.87)	0.9602
Partial	43	-3.64 (-6.62 to -0.66)	0.0257
Whole	80	-4.56 (-7.00 to -2.11)	0.0006
Anti-VEGF therapy
No	175	-1.03 (-2.56 to 0.50)	0.1891
Yes	59	-3.95 (-6.57 to -1.32)	0.0055
Insulin treatment
No	113	-1.16 (-2.82 to 0.49)	0.1711
Yes	121	-2.34 (-4.42 to -0.25)	0.0304
Oral glucose-lowering drugs
No	59	-2.85 (-5.15 to -0.56)	0.0180
Yes	175	-2.13 (-3.27 to -0.99)	0.0003
Calcium antagonists
No	183	-1.27 (-2.56 to 0.02)	0.0550
Yes	50	-3.00 (-7.47 to 1.48)	0.1993
Total cholesterol group (mmol/L)
< 6.22	119	-1.78 (-3.74 to 0.18)	0.0788
≥ 6.22	12	Not applicable
eGFR group (mL/minutes × 1.73 m2)
< 30	30	-3.83 (-8.33 to 0.68)	0.1198
≥ 30, < 60	61	-3.45 (-7.12 to 0.22)	0.0719
≥ 60, < 90	81	-1.47 (-4.21 to 1.27)	0.2976
≥ 90	62	0.11 (-1.87 to 2.08)	0.9161

Not applicable means that the model failed because of the small sample size. The adjustment strategy for each stratification was identical to that of Model III except for the stratification factor. CI: Confidence interval; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; eGFR: Estimated glomerular filtration rate; SFCT: Subfoveal choroidal thickness; VEGF: Vascular endothelial growth factor; PRP: Pan-retinal photocoagulation.