Table 1

Characteristics of the dementia risk scores with comparisons of the categorisations used in the original CAIDE study3 and the current study (modified from7)

	CAIDE categories	CAIDE in FTC	CAIDE score (max 15)*	Educational-occupational categories		Self-report score (max 25)
Age, years	<47	<47	0	Education, years	Less than 6	0
	47–53	47–53	3		6	4
	>53	>53	4		7–8	6
					9	6
Education, years	≥10	≥10	0		10–11	7
	7−9	7–9	2		12 or more	11
	0−6	0−6	3	Work status	Not working	0
					Home maker	1
Gender	Female	Female	0		Working/studying	1
	Male	Male	1	Nature of work	Very monotonous	0
					Somewhat monotonous/somewhat variable	2
Midlife high BP	Systolic BP ≤140 mm Hg	BP found to be normal	0		Very variable	2
	Systolic BP >140 mm Hg	BP found to be high/slightly elevated	2	Work environment	Outdoors or both outdoors and indoors	0
					Indoors	1
Midlife BMI	≤30 kg/m²	≤30 kg/m²	0	Physical loading of work	Heavy manual labour	0
	>30 kg/m²	>30 kg/m²	2		Manual labour: standing and walking+lifting and carrying	1
					Manual labour: standing and walking	1
Midlife cholesterol level	≤6.5 mmol/L	Cholesterol found normal	0		Mainly sitting, very little physical activity required	1
	>6.5 mmol/L	Cholesterol found high	2	Age in years	≥60	0
					54–59	4
Midlife physical activity	Active (physical activity ≥2 times/week, lasting at least 20–30 min per time, causing sweating and breathlessness)	Active (physical activity at least six times/month, at least 30 min mean duration, intensity corresponding at least vigorous walking)	0		47–53	6
					40–46	8
					≤39	9
	Inactive†	Inactive†	1

Educational-occupational score is based on Vuoksimaa et al.10
*The original CAIDE score encompasses a scoring system with or without APOE allele status. We used the scoring system without APOE allele status because our MZ within-family analyses are naturally matched for the APOE allele status.
†Physically inactive means that the participant does not fulfil the criteria of physically active.
BMI, body mass index; BP, blood pressure; CAIDE, Cardiovascular Risk Factors, Aging and Dementia; CR, cognitive reserve; FTC, Finnish Twin Cohort.