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Sample Size Estimates Using FDG PET for Alzheimer Disease Trials5 Number of Alzheimer Disease Patients Per Treatment Group Needed to Detect an Effect With 80% Power in 1 Year
| Treatment Effect
|
||||
|---|---|---|---|---|
| 20% | 30% | 40% | 50% | |
| Frontal | 85 | 38 | 22 | 14 |
| Parietal | 217 | 97 | 55 | 36 |
| Temporal | 266 | 119 | 68 | 44 |
| Cingulate | 343 | 153 | 87 | 57 |
| Combined | 62 | 28 | 16 | 10 |
P = 0.01 (two-tailed).
No adjustment for normal aging effects or subject attrition.
Adapted from Alexander et al, 2002.
