Table 4.

Power Calculations for a Theoretical Clinical Trial: Sample Sizes for Fixed Treatment Effects and 80% Power

		Braak stage					Drug effect
NP test	All	High	Moderate	Low	Placebo slope	SE	% Improvement	Drug Slope	Power
CDR-SOB		130	130	130	1.071	0.054	0.2	0.857	0.803
		0	0	420	0.916	0.046	0.2	0.733	0.803
		0	700	0	0.858	0.043	0.2	0.686	0.808
		230	0	0	1.439	0.073	0.2	1.151	0.799
	1176				1.172	0.059	0.2	0.938	0.800
		58	58	58	1.071	0.081	0.3	0.750	0.804
		0	0	185	0.916	0.069	0.3	0.641	0.799
		0	305	0	0.858	0.065	0.3	0.601	0.800
		103	0	0	1.439	0.109	0.3	1.007	0.802
	523				1.172	0.089	0.3	0.821	0.800
Logical		197	197	197	–0.710	0.036	0.2	–0.568	0.800
memory		0	0	1095	–0.454	0.023	0.2	–0.363	0.800
		0	400	0	–0.842	0.043	0.2	–0.674	0.800
		552	0	0	–0.834	0.042	0.2	–0.668	0.799
	1575				–0.677	0.034	0.2	–0.542	0.801
		88	88	88	–0.710	0.054	0.3	–0.497	0.802
		0	0	490	–0.454	0.034	0.3	–0.317	0.803
		0	178	0	–0.842	0.064	0.3	–0.590	0.800
		246	0	0	–0.834	0.063	0.3	–0.584	0.800
	700				–0.677	0.051	0.3	–0.474	0.801
Vegetable		927	927	927	–0.599	0.030	0.2	–0.480	0.800
naming		0	0	40600	–0.202	0.010	0.2	–0.162	0.800
		0	1550	0	–0.692	0.035	0.2	–0.554	0.800
		735	0	0	–0.904	0.046	0.2	–0.723	0.801
	928				–0.887	0.045	0.2	–0.709	0.800
		412	412	412	–0.599	0.045	0.3	–0.420	0.800
		0	0	18050	–0.202	0.015	0.3	–0.141	0.800
		0	690	0	–0.692	0.052	0.3	–0.485	0.801
		326	0	0	–0.904	0.068	0.3	–0.633	0.800
	413				–0.887	0.067	0.3	–0.621	0.801