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Zorluk: ZorMeasures of Disease Frequency and Association

A 34-year-old man with moderate-to-severe Crohn disease visits his gastroenterologist to discuss starting a newly approved interleukin-23 (IL-23) inhibitor. The physician reviews the pivotal 52-week clinical trial data with the patient. In this study, 1,0001,000 adult patients with Crohn disease were equally divided into an experimental arm receiving the IL-23 inhibitor and a control arm receiving a visually matched placebo. By the end of the observation period, 325325 patients receiving the active drug and 200200 patients receiving the placebo had successfully maintained clinical remission. Additionally, the safety analysis revealed that 4040 patients on the active drug experienced a severe upper respiratory tract infection requiring hospitalization, compared to 1515 patients in the placebo group. Based on the data presented, which of the following statements most accurately quantifies the treatment effect and risk of the IL-23 inhibitor over a 52-week period?

  1. Treating 44 patients will maintain remission in one additional patient, and treating 2020 patients will cause one additional severe infection.Cevap
  2. B
    Treating 44 patients will maintain remission in one additional patient, and treating 4040 patients will cause one additional severe infection.
  3. C
    Treating 88 patients will maintain remission in one additional patient, and treating 2020 patients will cause one additional severe infection.
  4. D
    Treating 88 patients will maintain remission in one additional patient, and treating 4040 patients will cause one additional severe infection.
  5. E
    Treating 2020 patients will maintain remission in one additional patient, and treating 44 patients will cause one additional severe infection.

Cevap

Treating 4 patients will maintain remission in one additional patient, and treating 20 patients will cause one additional severe infection.
The correct answer accurately determines both metrics. First, calculate the experimental event rate (EER) and control event rate (CER) for the favorable outcome. EER = 325/500=0.65325/500 = 0.65 (65%65\%). CER = 200/500=0.40200/500 = 0.40 (40%40\%). The absolute risk reduction (ARR) is 0.65−0.40=0.250.65 - 0.40 = 0.25. The Number Needed to Treat (NNT) is 1ARR=10.25=4\frac{1}{\text{ARR}} = \frac{1}{0.25} = 4. Next, calculate the rates for the adverse outcome. EER for infection = 40/500=0.0840/500 = 0.08 (8%8\%). CER for infection = 15/500=0.0315/500 = 0.03 (3%3\%). The absolute risk increase (ARI) is 0.08−0.03=0.050.08 - 0.03 = 0.05. The Number Needed to Harm (NNH) is 1ARI=10.05=20\frac{1}{\text{ARI}} = \frac{1}{0.05} = 20.

Adım Adım Çözüm

1
Determine the incidence of the favorable outcome (remission) in both groups.
Experimental event rate (EER) = 325/500=0.65325 / 500 = 0.65 (65%65\%). Control event rate (CER) = 200/500=0.40200 / 500 = 0.40 (40%40\%).
These rates are required to calculate the absolute risk reduction.
2
Calculate the Absolute Risk Reduction (ARR) and Number Needed to Treat (NNT).
ARR=0.65−0.40=0.25\text{ARR} = 0.65 - 0.40 = 0.25. NNT=10.25=4\text{NNT} = \frac{1}{0.25} = 4.
NNT quantifies the number of patients required to achieve one additional favorable outcome.
3
Determine the incidence of the adverse outcome (severe infection) in both groups.
Experimental event rate for infection = 40/500=0.0840 / 500 = 0.08 (8%8\%). Control event rate for infection = 15/500=0.0315 / 500 = 0.03 (3%3\%).
These rates are required to calculate the absolute risk increase.
4
Calculate the Absolute Risk Increase (ARI) and Number Needed to Harm (NNH).
ARI=0.08−0.03=0.05\text{ARI} = 0.08 - 0.03 = 0.05. NNH=10.05=20\text{NNH} = \frac{1}{0.05} = 20.
NNH quantifies the number of patients required to cause one additional adverse event.

Anahtar Kavram

Number Needed to Treat (NNT) and Number Needed to Harm (NNH)
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Konular

Measures of Disease Frequency and Association

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