## Sample Size Calculator for Pilot Study

Below is a basic template for a sample size table, including common parameters and considerations:

### Sample Size Calculation Table for a Pilot Study

Parameter | Description | Value |
---|---|---|

Study Design | Type of study (e.g., randomized controlled trial, cohort) | |

Outcome Measure | Primary outcome variable | |

Expected Effect Size | Estimated effect size based on prior research or pilot data | |

Variability | Standard deviation of the outcome measure | |

Significance Level (α) | Probability of Type I error (commonly 0.05) | |

Power (1 – β) | Probability of detecting an effect if one exists (commonly 0.80) | |

Sample Size Calculation Method | Method used (e.g., formulas, software) | |

Initial Sample Size Estimate | Calculated sample size for pilot study | |

Adjusted Sample Size | Adjusted for expected dropouts or non-response | |

Final Sample Size | Recommended sample size for pilot study |

### Key Considerations

**Study Design**: This affects how sample size is calculated. Different designs (e.g., parallel groups, crossover) may require different approaches.**Expected Effect Size**: This is crucial; smaller effect sizes typically require larger samples.**Variability**: Higher variability in the outcome measure requires a larger sample size.**Significance Level and Power**: Common values are α = 0.05 and power = 0.80, but these can be adjusted based on the study’s requirements.**Dropout Rate**: Adjust the sample size to account for participants who may drop out or not respond, typically by increasing the initial estimate by a certain percentage.

### Example Calculation

For a pilot study with the following parameters:

- Study Design: Randomized Controlled Trial
- Outcome Measure: Blood Pressure Reduction
- Expected Effect Size: 5 mmHg
- Variability: 10 mmHg
- Significance Level (α): 0.05
- Power (1 – β): 0.80

Using a standard sample size formula (for a two-sample t-test), you might calculate an initial sample size of around 30 participants per group. Adjusting for a 20% dropout rate would lead to a final recommendation of approximately 36 participants per group.