Table 1.

Power analysis—table of data.

	Power (%), number of patients
	40	50	60	70	80	90
Small effect size (Cohen, 1 – d = 0.8)	7	8	10	12	14	18
EQ-5D: expected SRMa (1 – d = 0.76)	7	9	11	13	16	20
SF-6Db: expected SRM (1 – d = 0.61)	10	12	15	19	23	30
Medium effect size (Cohen, 1 – d = 0.5)	14	17	22	27	33	44

^aSRM: standardized response mean.

^bSF: Short-Form.