TABLE 2.
Study Results for Low Education and Dementia Incidence (N=42)
| First Author (Year) | Country, Study Name | Sample Size | Age | Number & Type of Dementia Cases | Adjustment variables | Education Variable | OR/RR/HR (95% CI) | |||
|---|---|---|---|---|---|---|---|---|---|---|
| AD | p | Total Dementia | p | |||||||
| EUROPE (N=19) | ||||||||||
| Bickel50 (1994) | Germany | 422 | ≥ 65 | 60 TD | Age | Elementary only > Elementary | 1.48 (0.60–3.40)^ 1 |
|||
| Paykel51 (1994) | United Kingdom | 1195 | ≥ 75 | 49 TD | Age | <14 years ≥ 14 years |
Not given 1 |
n.s. | ||
| Persson52 (1996) | Sweden | 374 | ≥ 70 | 38 TD | Unadjusted | > Elementary Any vocational | Not given 1 |
n.s. | ||
| Schmand53 (1997) | Amsterdam, AMSTEL | 2063 | ≥ 65 | 152 TD | Age, sex, DART-IQ, occupation, management, # of diseases, family history | ≥ 8 years >8 years |
0.86 (0.57–1.31)^ 1 |
|||
| Geerlings54 (1999) | Netherlands, AMSTEL | 3778 | ≥ 55 | 77 AD | Age, sex | ≥ 6 years > 6 years |
2.09 (1.29–3.38) 1 |
|||
| Launer55 (1999) | Europe, EURODEM | 12,943 | ≥ 65 | 352 AD | Age, age-squared, sex, study |
Women < 8 years > 11 years |
4.55 (1.64–12.57) 1 |
|||
|
Men < 8 years > 11 years |
1.00 (0.48–2.04)^ 1 |
|||||||||
| Letenneur56 (1999) | France, PAQUID study | 2881 | ≥ 65 | 140 AD 190 TD |
Age, sex | < Primary school ≥ Primary school |
1.81 (1.30–2.53) 1 |
<0.001 | 1.83 (1.37–2.44) 1 |
<0.001 |
| Nielsen57 (1999) | Denmark, Odense Study | 2452 | ≥ 65 | 102 AD | Unadjusted | < 7 years ≥ 7 years |
Not given | 0.003 | ||
| Ott58 (1999) | Netherlands, Rotterdam Study | 6827 | ≥ 55 | 97 AD 137 TD |
Age, Age-squared | Women < 7 years ≥ 11 years* | 2.00 (1.00–3.90)^ 1 |
2.10 (1.10–3.90) 1 |
||
| Men < 7 years ≥ 11 years* | 0.60 (0.20–1.70)^ 1 |
0.70 (0.30–1.50)^ 1 |
||||||||
| Gatz25 (2001) | Sweden | 54:108 AD C/C 90:180 TD C/C |
≥ 65 | 54 AD 90 TD |
Age, sex | ≤ 6 years >6 years |
2.17 (0.69–6.86)^ 1 |
1.25 (0.60–2.60)^ 1 |
||
| Qiu59 (2001) | Sweden, Kungsholmen Project | 1296 | ≥ 75 | 109 AD 147 TD |
Age, sex | < 8 years ≥ 11 years* |
2.70 (1.40–5.00) 1 |
2.10 (1.30–3.50) 1 |
||
| Anttila60 (2002) | Finland | 1449 | ≥ 65 | 70 TD | Unadjusted | Years of Education Ŧ | 1.22 (1.11–1.35) | |||
| Di Carlo61 (2002) | Italy, ILSA | 3208 | ≥ 65 | 67 AD 127 TD | Age, sex | 0–5 years 11 years Ŧ* |
2.94 (1.04–8.33) 1 |
2.27 (1.18–4.35) 1 |
||
| Karp62 (2004) | Sweden, Kungsholmen Project | 931 | ≥ 75 | 76 AD 101 TD |
Age, sex | 2–7 years >10 years* |
2.70 (1.30–5.40) 1 |
2.40 (1.30–4.40) 1 |
||
| Ravaglia63 (2005) | Italy, CSBA | 937 | ≥ 65 | 72 AD 115 TD |
Age, sex | ≤ 3 years ≥ 6 years* |
2.66 (1.02–6.89) 1 |
0.04 | 2.20 (1.07–4.53) 1 |
0.03 |
| Brayne64 (2010) | Europe, EClipSE | 872 | >65 | 486 TD | Unadjusted | Years of Education Ŧ | 1.12 (1.06–1.20) | |||
| NORTH AMERICA (N=18) | ||||||||||
| Beard65 (1992) | USA, Rochester Epidemiology Project | 241:241 C/C | Not given | 241 AD | Unadjusted | < 9 years ≥ 9 years Ŧ |
1.13 (0.69–1.85)^ 1 |
|||
| Hebert66 (1992) | USA East Boston Study | 513 | ≥ 65 | 76 AD | Unadjusted | 0–7 years ≥ 8 years Ŧ |
3.79 (2.29–6.26) 1 |
|||
| Stern67 (1994) | USA | 593 | ≥ 60 | 106 TD | Age, sex | < 8 years ≥ 8 years |
2.02 (1.33–3.06) 1 |
|||
| Cobb68 (1995) | USA, Framingham Study | 3330 | ≥ 55 | 149 AD 258 TD |
Age | < Grade School ≥ High School* |
1.04 (0.62–1.74)^ 1 |
1.31 (0.90–1.90)^ 1 |
||
| Evans69 (1997) | USA, Boston (EPESE) | 642 | ≥ 65 | 95 AD | Age, sex, follow-up interval | Years of Education Ŧ | 1.20 (1.09–1.33) | |||
| Elias70 (2000) | USA Framingham Study | 1076 | ≥ 65 | 109 AD | Unadjusted | ≤ 8th grade >High School |
0.75 (0.33–1.69)^ 1 |
|||
| Ganguli16 (2000) | USA MoVIES Project | 1298 | ≥ 65 | 94 AD 110 TD (CDR ≥ 1.0) |
Age, sex | < High School ≥ High School |
Not given^ 1 |
n.s. | Not given^ 1 |
n.s. |
| Kawas71 (2000) | USA, BLSA | 1236 | ≥ 55 | 114 AD | Age, sex | 4–12 years 17–25 years Ŧ* |
1.56 (0.84–2.94)^ 1 |
0.16 | ||
| Lindsay72 (2002) | Canada, CSHA | 194:3894 C/C | 65 | 194 AD | Age, sex | 0–8 years ≥ 13 years* |
1.90 (1.25–2.90) 1 |
|||
| Kukull73 (2002) | USA, ACT – Seattle | 2356 | ≥ 65 | 151 AD 215 TD |
Age, sex, APOE | <12 years >15 years Ŧ* |
2.08 (1.19–3.70) 1 |
1.56 (1.00–2.50)^ 1 |
||
| Wilson74 (2002) | USA, Religious Orders Study | 801 | ≥ 65 | 111 AD | Age, sex | Years of Education Ŧ | 0.99 (0.93–1.05)^ | |||
| Kuller75 (2003) | USA CHS-CS | 3608 | ≥ 65 | 480 TD | Age | < 8th grade ≥ 17 years* |
1.70 (1.16–2.41) 1 |
|||
| Tuokko76 (2003) | Canada, CSHA | 838 | ≥ 65 | 230 TD | Age, sex | ≤ 6 years ≥ 11 years |
1.10 (1.06–1.15) 1 |
<0.01 | ||
| Fitzpatrick77 (2004) | USA, CHS | White 2867 | ≥ 65 | White 401 TD | Age |
White < High School ≥ Some College* |
Not given 1 |
<0.0001 | ||
| Black 492 | Black 76 TD | Age |
Black < High School ≥ Some College* |
Not given^ 1 |
0.79 | |||||
| Shadlen78 (2006) | USA, CHS | White 2,102 | Not given | White 401 TD | Age, sex, ascertainment method |
White ≤ 10 years > 10 years |
1.8 (1.39–2.23) 1 |
|||
| Black 207 | Black 76 TD |
Black ≤ 10 years > 10 years (white) |
4.6 (3.13–6.82) 1 |
|||||||
| McDowell79 (2007) | Canada, CSHA | 5177 | ≥ 65 | 532 AD 783 TD | Age, sex, marital status | < 6 years ≥ 13 years* |
2.60 (1.91–3.53) 1 |
2.60 (2.02–3.38) 1 |
||
| ASIA (N=5) | ||||||||||
| Li80 (1991) | China | 1090 | ≥ 60 | 13 TD | Age | Illiterate Literate | 2.47 (not given)^ 1 |
0.10 | ||
| Yoshitake81 (1995) | Japan, Hisayama Study | 828 | ≥ 65 | 42 AD | Age | ≤ 6 years > 6 years |
1.18 (0.61–2.27)^ 1 |
|||
| Liu82 (1998) | Taiwan | 1507 | ≥ 65 | 25 AD 60 TD |
Age, sex | Illiterate Literate Ŧ | 1.39 (0.52–3.70)^ 1 |
1.59 (0.85–2.94)^ 1 |
||
| He83 (2000) | China | 3024 | ≥ 55 | 92 AD | Age, sex | Illiterate Any education* | 3.22 (2.15–4.82) 1 |
|||
| Yamada84 (2008) | Japan, AHS/RERF | 2286 | ≥ 65 | 80 AD 206 TD |
Age, age2, sex, sex* age | ≤ 6 years ≥7 years Ŧ |
2.50 (not given) 1 |
0.001 | 1.67 (not given) 1 |
0.003 |
| LATIN AMERICA (N=1) | ||||||||||
| Nitrini85 (2004) | Brazil | 1538 | ≥ 65 | 50 TD | Unadjusted | Illiterate (0) ≥ 8 years* |
2.07 (0.60–7.09)^ 1 |
|||
Note.
Ŧ
Reciprocal of original study risk estimate is given so that all studies are low education compared to high education.
*
Original study reported results for 3 or more categories of education, here we report the lowest level compared to the highest level of education.
^
Result not significant: 95% Confidence Interval includes 1.00 or p > 0.05.
AD = Alzheimer’s disease; TD= Total Dementia; CI = Confidence Interval; C/C= case control; OR= Odds Ratio; RR=Relative Risk; HR=Hazard Ratio.
Study Acronyms: Amsterdam Study of the Elderly (AMSTEL), European Studies of Dementia (EURODEM), Italian Longitudinal Study of Aging (ILSA), Conselice Study of Brain Aging (CSBA), Epidemiological Clinicopathological Studies in Europe (EClipSE), Established Populations for Epidemiologic Studies of the Elderly (EPESE), Monongahela Valley Independent Elders Survey (MoVIES), Baltimore Longitudinal Study of Aging (BLSA), Canadian Study of Health and Aging (CSHA), Adult Changes in Thought (ACT), Cardiovascular Health Study Cognition Study (CHS-CS), Cardiovascular Heatlh Study (CHS), Adult Health Study (AHS)/Radiation Effects Research Foundation (RERF).