An international consortium of clinicians publishes the safety outcomes of a phase 3 clinical trial evaluating a novel Janus kinase (JAK) inhibitor for refractory rheumatoid arthritis. The study randomized patients equally into two arms: subjects received the active drug, while subjects received a placebo. During the -year observation window, severe opportunistic infections were documented in individuals taking the JAK inhibitor and in individuals taking the placebo.
Based on this data, what is the number of patients that need to be treated with the active drug to result in one additional severe opportunistic infection?
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Answer
The correct answer is , which represents the Number Needed to Harm (NNH).
The Number Needed to Harm (NNH) is an epidemiological metric that represents the number of patients who need to be exposed to a risk factor (or treated with a drug) to cause one additional adverse event. It is calculated as the inverse of the Absolute Risk Increase (ARI). First, calculate the incidence of the adverse event in the exposed group (). Next, calculate the incidence in the unexposed group (). The ARI is the difference between these two incidences (). Therefore, .
Step-by-Step Solution
Key Concept
Number Needed to Harm (NNH) Calculation