Table 1.
Baseline characteristics of studies
| Study | Design | Outcomes | No. at risk |
No. of Events |
Mean Age |
Sex (female) |
Follow- up time (yrs) |
Adjusted For | Dementia | AD | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dem. | AD | RR (Aβ42) |
RR (Aβ42:Aβ40) |
RR (Aβ42) |
RR (Aβ42:Aβ40) |
||||||||
| Abdullah 2009 | cohort | AD | 203 | -- | 14 | 76.8 | 48.3% | 2.1 (median) | age, sex, education | -- | -- | 4.47 (1.19,9.85) | 3.91 (1.36,11.24) |
| Graff-Radford 2007 | cohort | AD, cognitive change | 563 | -- | 17 | 78.0 (median) | 62.0% | 3.7 (median) | age, APOE | -- | -- | 1.18 (0.50,2.75) | 3.08 (1.12,8.3) |
| Lambert 2009 | case-cohort | AD, dementia | 8414 | 233 | 154 | 74.6 | 60.4% | 4 | age, gender, education, site | 1.33 (0.97,1.92) | 2.00 (1.41,2.78) | -- | 2.08 (1.30,3.23) |
| Mayeux 2003 | cohort | AD | 451 | -- | 86 | 76.2 | 68.9% | 5 | age, education, APOE, Aβ40 level, BMI | -- | -- | 0.4 (0.21,0.77) | -- |
| Schupf 2008 | cohort | AD | 1125 | -- | 104 | 76.9 | 68.3% | 4.6 (mean) | age, sex, APOE, education, ethnicity, BMI, cohort membership | -- | -- | 0.29 (0.12,0.71) | 1.11 (0.59,2.00) |
| Seppalla 2010a | cohort | Dementia | 197 | 9c | -- | 70.0a | 55.0%a | 3 | unknown | 3.12 (1.25,7.79) | 3.26 (1.31,8.11) | -- | -- |
| Seppalla 2010b | cohort | Dementia | 60 | 7c | -- | 70.0a | 55.0%a | 6 | unknown | 4.77 (1.14,19.98) | 8.4 (1.83,83.57) | -- | -- |
| Sundelof 2008a | cohort | AD, dementia | 1045 | 146 | 82 | 71.0 | 0.0% | 11.2 (median) | age, APOE | 0.7 (0.44,1.13) | 0.67 (0.42,1.08) | 0.85 (0.48,1.50) | 0.89 (0.54,1.48) |
| Sundelof 2008b | cohort | AD, dementia | 680 | 74 | 46 | 77.6 | 0.0% | 5.3 (median) | AD: age dementia: age, APOE, diabetes | 1.58 (0.87,2.86) | 1.06 (0.59,1.90) | 2.5 (1.04,6.03) | 1.27 (0.61,2.66) |
| van Oijen 2006b | case-cohort | AD, dementia | 6713 | 392 | 289 | 68.6 | 61.0% | 8.6 (mean) | age, sex | 1.16 (0.82,1.64) | 2.13 (1.49,3.03) | -- | -- |
Abbreviations: AD = Alzheimer’s disease; Aβ = Amyloid beta; APOE = Apolipoprotein E; BMI = Body Mass Index; Dem = Dementia
a
study population data is for entire cohort
b
only continuous RR reported for AD outcome
c
number of events estimated from published data
Note: confidence intervals reflect published results, before random-effects weighting