Table 2.

Risk of incident dementia (2003–2019) by use of estrogen replacement therapy data collected in the 1980s.

			Hazard Ratio (95% CI)*
	No dementia (n=215)	Dementia (n=209)	Univariate	Adjusted for education
Estrogen replacement therapy (ERT)
Never	68 (32%)	59 (28%)	1.00	1.00
Ever	147 (68%)	150 (72%)	0.96 (0.71–1.30)	0.94 (0.69–1.28)
ERT duration in years (2 missing)
≤ 3	39 (18%)	49 (23%)	1.02 (0.70–1.49)	1.04 (0.71–1.53)
4–14	50 (23%)	62 (30%)	1.27 (0.89–1.83)	1.32 (0.92–1.91)
15+	56 (26%)	39 (19%)	0.84 (0.56–1.27)	0.85 (0.57–1.28)
ERT years since last use (2 missing)
15+	19 (9%)	33 (16%)	1.04 (0.68–1.59)	1.06 (0.69–1.64)
2–14	66 (31%)	67 (32%)	1.10 (0.77–1.56)	1.13 (0.79–1.61)
0–1	60 (28%)	50 (24%)	0.99 (0.68–1.45)	1.00 (0.68–1.46)
ERT dose of Premarin® in mg (76 other estrogen)
≤ 0.62	52 (29%)	54 (32%)	1.05 (0.72–1.53)	1.07 (0.73–1.55)
≥ 1.25	60 (33%)	55 (33%)	0.95 (0.66–1.38)	0.95 (0.66–1.38)
Estrogen type
Oral estrogen only	90 (42%)	94 (45%)	1.00 (0.72–1.38)	1.02 (0.73–1.42)
Oral and other estrogen	45 (21%)	46 (22%)	1.17 (0.79–1.73)	1.18 (0.80–1.75)
Injection and cream	12 (6%)	10 (5%)	0.99 (0.51–1.95)	0.99 (0.51–1.95)

^*All hazard ratios are relative to category “Never estrogen”