Sample Size : Power : Confidence Intervals : Pilot Studies :

Data Input for Sample Size Estimation is a table of 4 columns

• Each row contains data from a separate study
• Col 1 = probability of Type I error (alpha)
• Col 2 = power (1-beta)
• Col 3 = proportion expected in grp 1
• Col 4 = proportion expected in grp 2

Data Input for Power Estimation is a table of 5 columns

• Each row contains data from a separate study
• Col 1 = probability of Type I error (alpha)
• Col 2 = sample size in group 1
• Col 3 = proportion found in group 1
• Col 4 = sample size in group 2
• Col 5 = proportion found in group 2

Data Input for Confidence Interval Study is is a table of 5 columns

• Each row contains data from a separate study
• Col 1 = percent confidence (usually 95)
• Col 2 = sample size in group 1
• Col 3 = proportion found in group 1
• Col 4 = sample size in group 2
• Col 5 = proportion found in group 2

Data Input for Pilot Study is for a single plan, a single column with 5 rows

• Row 1 : Percent Confidence required, usually 95 or 99
• Row 2 : Planned Proportion in Group 1
• Row 3 : Planned Proportion in Group 2
• Row 4 : Sample Size Interval, usually 5
• Row 5 : Maximum Sample size, usually 50

Machin D, Campbell M, Fayers, P, Pinol A (1997) Sample Size Tables for Clinical Studies. Second Ed. Blackwell Science IBSN 0-86542-870-0 p. 18-20