Adverse Event Detection & Clinical Trial Power Lab

Parameters & Base Rates

True Adverse Event Rate 2.5 per 100k

Rate per 100,000 vaccinated individuals

Disease Baseline Incidence 1,200 per 100k

Intervention Efficacy 92%

Phase III Cohort Size (N) 40,000

Phase IV Population (N) 2,500,000

Statistical Confidence Goal 95% (Rule of 3)

Biostatistical Rule of Three:
To have a 95% chance of observing at least 1 rare adverse event with true rate 1 in 40,000, a trial requires a sample size of 120,000 participants.

Binomial Detection Power by Clinical Trial Phase P(k ≥ 1) = 1 - (1 - p)^N

Phase III Detection Power

63.21%

N = 40,000 cohort

Phase IV Post-Market Power

99.99%

N = 2,500,000 surveillance

Rule of 3 Sample Needed

120,000

For 95% certainty of ≥1 event

Benefit-Risk Ratio

441.6

Prevented Cases / Adverse Event

Phase	Typical Sample Size (N)	Expected Events	Detection Power P(≥1)	Surveillance Status

Stochastic Trial Cohort Simulator (N = 500 Dot Sample) Scaled micro-cohort

Each dot represents a vaccinated individual in a scaled clinical micro-cohort. Green indicates prevented severe disease cases, blue indicates healthy protected recipients, and red indicates observed serious adverse reactions.

Prevented: 0 Adverse: 0

Population Health Balance (Per Million Patients) Absolute Impact Metric

Clinical Metric	Value per 1,000,000	Interpretation
Baseline Disease Cases	12,000	Without vaccination / intervention
Prevented Severe Cases	11,040	Cases averted via efficacy
Expected Rare Adverse Events	25	True rate: 2.5 / 100k
Net Prevented Burden	+11,015	Lives protected minus severe reactions
Number Needed to Treat (NNT)	91	Patients treated to prevent 1 disease case
Number Needed to Harm (NNH)	40,000	Patients treated before 1 adverse event

Biostatistical takeaway: Clinical trials with N=30,000 to N=50,000 are powered to detect side effects that occur in 1 in 10,000 or more frequent. Ultra-rare events (1 in 40,000 to 1 in 100,000) mathematically require Phase IV continuous pharmacovigilance (e.g. VAERS, Yellow Card, V-Safe) over millions of administered doses.