Here is the design of a clinical trial:

Official Title: ALFAsleep: Exploring Cognitive and Biological Correlates of Sleep Quality and Their Potential Links With Alzheimer's Disease

Included conditions:
- Cognitively Unimpaied

Study Armgroups:

Interventions:

Primary Outcomes:
- {'measure': 'Sleep quality', 'description': 'Actigraphy-derived sleep quality measures', 'timeFrame': 'up to 2 weeks'}

Please estimate the sample size based on the assumption: 
Statistical power of 90%, 5% type I error probability (two tails), and consideration of missing/dropout rate.
Sample size calculation
          The sample size has been computed with G*Power V.3.1.9.4,96 taking into account the estimated effect size (ES) of a previous study using a similar methodology for the detection of differences in sleep efficiency between cognitively unimpaired individuals with normal versus abnormal AÎ² biomarkers.24 For this ES (ES=0.49), we calculate that a sample size of n=178 (89 cases/89 controls) would be enough to achieve a statistical power of 90%, assuming a 5% type I error probability (two tails) (figure 2).
          
            Figure 2
            
              Estimation of statistical power as a function of sample size.
            
            
          
          Based on these estimations, we plan to recruit 200 subjects: 100 with altered AÎ² biomarkers and 100 with normal biomarkers. The sample size for the exploratory PSG substudy (n=90) is based on previous literature.44