Sample Size and Power

More documents

Recommendations

Info

Power is Affected by….. • Variation in the outcome (σ 2 ) – ↓ σ 2 → power ↑ • Significance level (α) – ↑ α → power ↑ • Difference (effect) to be detected (δ) – ↑δ →power ↑ • One-tailed vs. two-tailed tests – Power is greater in one-tailed tests than in comparable ab two-tailed ta tests
Power Changes • 2n = 32, 2 sample test, 81% power, δ=2, σ = 2, α = 0.05, 2-sided test • Variance/Standard deviation – σ: 2 → 1 Power: 81% → 99.99% – σ: 2 → 3 Power: 81% → 47% • Significance level (α) – α : 0.05 → 0.01 Power: 81% → 69% – α :0.05→ 0.10 Power: 81% → 94%
Page 1 and 2: Sample Size and Power Laura Lee Joh
Page 3 and 4: Misconceptions • A small p-value
Page 5 and 6: Take Away Message • Get some inpu
Page 7 and 8: Superiority vs. Equivalence Superio
Page 9 and 10: Vocabulary (2) • Follow-up period
Page 11: Power Depends on Sample Size • Po
Page 15 and 16: Power should be….? • Phase III:
Page 17 and 18: Outline Power ‣Basic Sample Size
Page 19 and 20: Basic Sample Size Information • W
Page 21 and 22: Take Away • Study’s primary out
Page 23 and 24: Sample Size Formula Information •
Page 25 and 26: Sample Size & Study Design • Rand
Page 27 and 28: Phase I: Dose Escalation • Dose l
Page 29 and 30: Phase I (cont.) • Maximum Tolerat
Page 31 and 32: Phase I Enroll 3 people 0/3 DLT 1/3
Page 37 and 38: Number of pts with DLT Decision 0/3
Page 39 and 40: Phase I • MANY new methods • Se
Page 41 and 42: Phase II Design Problems • Might
Page 43 and 44: Phase II Example: Two-Stage Optimal
Page 45 and 46: Table from Simon (1989)
Page 47 and 48: Phase II Example • Initially enro
Page 49 and 50: Sample Size Differences • If the
Page 51 and 52: Phase II: Historical Controls • W
Page 53 and 54: Study Design Phase II Summary Advan
Page 55: Number of Patients to Enroll? • 1
Page 58: Phase III Survival • Look at nomo
Page 61 and 62: 1-Sample N Example • Study effect
Page 63 and 64:
Short Helpful Hints • In humans n
Page 65 and 66:
Sample Size: Iteration and the Use
Page 67 and 68:
Sample Size: Change Standard d Devi
Page 69 and 70:
Sleep Aid Example: 2 Arms Investiga
Page 71 and 72:
Sample Size: Change Effect or Diffe
Page 73 and 74:
Sample Size: Change Standard d Devi
Page 75 and 76:
Live Statistical Consult! • Sampl
Page 77 and 78:
Sample Size Rulers
Page 79 and 80:
Put in 1-Sample Example #s • 1 ar
Page 81 and 82:
Put in 2-Sample Example #s • 2 ar
Page 83 and 84:
Other Designs?
Page 85 and 86:
Examples in the Text • Several wi
Page 87 and 88:
Take Home: What you need for N •
Page 89 and 90:
Outline Power Basic sample size inf
Page 91 and 92:
K:1 Sample Size Shortcut • Use eq
Page 93 and 94:
How many controls? k = 2n n 0 − n
Page 95 and 96:
Formulas and Example Risk of event
Page 97 and 98:
Balanced Designs: Easier to Find Po
Page 99 and 100:
Multiple Comparisons • If you hav
Page 101 and 102:
Outline Power Basic Sample Size Inf
Page 103 and 104:
No Prior Information • "Sample si
Page 105 and 106:
Number of Available Patients • "T
Page 107 and 108:
Conclusions: What Impacts Sample Si
Page 109 and 110:
Top 10 Statistics Questions 10.Exac
Page 111 and 112:
Top 10 Statistics Questions 4. Inte
Page 113 and 114:
Analysis Follows Design Questions
Page 115 and 116:
Resources: General/Text Books • A
Page 117 and 118:
Resources: Articles • Simon R. Op
Page 119 and 120:
Resources: FDA Guidance • http://
Page 121:
Questions?
show all

Sample Size and Power

Create successful ePaper yourself

Delete template?

Save as template?