Table 3.

Observed responsiveness (standardized placebo/tanezumab difference) for featured pain outcomes at trial timepoints, and required sample sizes for a hypothetical new trial of the same design, using these observed effect sizes.

Primary Outcome of New Trial	Week 2		Week 4		Week 8		Week 12		Week 16
Primary Outcome of New Trial	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	106,870	−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
No. RM pills taken/day	−0.08	4362	−0.33	290	−0.31	332	−0.25	496	−0.24	550
Composite 1: WOMAC pain and no. RM pills	−0.01	196,818	−0.41	190	−0.45	162	−0.39	214	−0.29	364
Composite 2: WOMAC pain, stiffness, and function	−0.09	3780	−0.44	164	−0.49	134	−0.45	156	−0.34	270
Composite 3: WOMAC P, S, F, no. 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 SD of 1, power of 0.8, and alpha level of 0.05, in all cases. WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; RM: rescue medication; P, S, F: WOMAC pain, stiffness, and function subscales.