Table 4.

Cox regression of diabetic retinopathy (DR) severity (N = 3294).

	Variables	Hazard ratio	95% CI		P-value
			Lower	Upper
Age
20–44 years	Sex (male vs. female)	1.04	0.94	1.14	0.45
	Periodic screening (yes vs. no)	1.04	0.74	1.46	0.82
46–64 years	Sex (male vs. female)	1.01	0.96	1.05	0.81
	Periodic screening (yes vs. no)	0.97	0.85	1.10	0.61
Over 65 years	Sex (male vs. female)	1.02	0.95	1.10	0.52
	Periodic screening (yes vs. no)	0.93	0.78	1.10	0.39
Sex
Male	46–64 years (ref. 20–44)	1.13	0.98	1.31	0.09
	Over 65 years (ref. 20–44)	0.95	0.78	1.15	0.59
	Periodic screening (yes vs. no)	0.86	0.74	1.00	0.05
Female	46–64 years (ref. 20–44)	1.06	0.90	1.24	0.51
	Over 65 years (ref. 20–44)	0.90	0.75	1.09	0.29
	Periodic screening (yes vs. no)	1.03	0.91	1.18	0.61