Randomization Skill

Purpose

Implement proper random assignment to minimize selection bias.

Randomization Methods

1. Simple Randomization

• Coin flip, random number generator
• Best for large samples (N>200)
• Risk of imbalance in small samples

2. Block Randomization

• Ensures equal group sizes
• Blocks of 4, 6, or 8
• Example: AABB, ABAB, BABA, BBAA

3. Stratified Randomization

• Balance prognostic factors
• Stratify by sex, age group, severity
• Then randomize within strata

4. Minimization

• Dynamic allocation
• Minimizes imbalance across factors
• Used in small trials

Implementation

Steps:

1. Generate random sequence (with seed)
2. Document sequence generation
3. Implement allocation concealment
4. Execute randomization
5. Document actual allocation

Example (Python):

import random
random.seed(12345)  # Document seed
sequence = ['A', 'B'] * 50  # 100 participants
random.shuffle(sequence)

---

Version: 1.0.0