A randomized controlled trial is conducted to evaluate a novel biologic agent for the treatment of moderate-to-severe plaque psoriasis. The study enrolls patients, who are randomly assigned in a 1:1 ratio to receive either the biologic agent or a placebo. After weeks, the patients are evaluated for disease progression. In the placebo group, of the patients experience disease progression. In the treatment group, of the patients experience disease progression. Based on these study results, what is the number needed to treat (NNT) with the new biologic agent to prevent one additional case of disease progression compared to placebo?
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Answer
The correct answer is .
The Number Needed to Treat (NNT) is determined by first calculating the Absolute Risk Reduction (ARR), which is the difference in the event rates between the control group and the experimental group. In this study, the Control Event Rate is () and the Experimental Event Rate is (). The ARR is . The NNT is the inverse of the ARR (), which equals .
Step-by-Step Solution
Key Concept
The Number Needed to Treat (NNT) is an epidemiological measure that indicates how many patients need to be treated with a specific intervention to prevent one additional adverse outcome. It is calculated as the inverse of the Absolute Risk Reduction (ARR).