Table 2. Required Sample Sizes for a Hypothetical New Trial of the Same Design, Using the Observed Effect Sizes from the Present Trial as the Basis of the Sample Size Calculation.

Primary Outcome of New Trial	Week 2		Week 4		Week 8		Week 12		Week 16
	Expected Between-groups standard-score difference	Required sample size to detect this difference	Expected Between-groups standard-score difference	Required sample size to detect this difference	Expected Between-groups standard-score difference	Required sample size to detect this difference	Expected Between-groups standard-score difference	Required sample size to detect this difference	Expected Between-groups standard-score difference	Required sample size to detect this difference
WOMAC Pain Subscale	0.02	106870	-0.37	236	-0.44	164	-0.38	222	-0.26	476
WOMAC Physical Function Subscale	-0.08	4874	-0.41	188	-0.45	158	-0.42	184	-0.33	298
WOMAC Stiffness Subscale	-0.21	748	-0.52	122	-0.54	108	-0.54	112	-0.43	176
Number of RM Pills Taken/day	-0.08	4362	-0.33	290	-0.31	332	-0.25	496	-0.24	550
Composite 1: WOMAC pain & number of RM pills	-0.01	196818	-0.41	190	-0.45	162	-0.39	214	-0.29	364
Composite 2: WOMAC Pain, Stiffness, & Function	-0.09	3780	-0.44	164	-0.49	134	-0.45	156	-0.34	270
Composite 3: WOMAC P, S, F, & number of RM pills	-0.09	3600	-0.46	154	-0.49	132	-0.47	146	-0.35	260

Sample sizes are calculated for a hypothetical new trial with an expected between-groups standard deviation of 1, power of 0.8, and alpha level of 0.05, in all cases.