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Centre for Evidence-
Based Medicine

Completed Therapy Worksheet for Child Health

Clinical Question

In children of mild to moderate croup does nebulized budesonide or placebo reduce the risk of hospital admission?

Are the results of this single preventive or therapeutic trial valid?

  1. Was the assignment of patients to treatments randomised? And was the randomisation list concealed?
    Yes, and randomisation performed by pharmacy as concealed.
  2. Were all patients who entered the trial accounted for at its conclusion? And were they analysed in the groups to which they were randomised?
  3. Were patients and clinicians kept "blind" to which treatment was being received?
    Yes. Both budesonide and placebo were given in opaque chambers.
  4. Were the groups similar at the start of the trial?
    Yes - more or less. Slightly longer duration of cough and higher temperature in experimental group.

Are the valid results of this randomised trial important?

Sample calculations:

Occurrence of childhood asthma Relative Risk Reduction (RRR) Absolute Risk Reduction (ARR) Number Needed to Treat (NNT)
Usual Insulin Control Event Rate (EER) Intensive Insulin Experimental Event Rate (CER) (CER - EER) / CER CER - EER 1 / ARR
2.8% 9.6% (9.6% - 2.8%) / 9.6%
= 71%
9.6% - 2.8% = 6.8% 1 / 6.8% = 15 pts

95% Confidence Interval (CI) on an NNT = 1 / (limits on the CI of its ARR) = +-1.96 sqrt(((CERx(1-CER))/(# of control pts))+((EERx(1-EER))/(# of exper pts)))
= +-1.96 sqrt(((0.96x0.904)/730)+(0.028x0.972)/711))
= ±2.4%

Your calculations:

Risk of hospital admission one week later Relative Risk Reduction (RRR) Absolute Risk Reduction (ARR) Number Needed to Treat (NNT)
1/27 = 0.4 7/27 = 0.26 0.85 0.22 5

Can you apply this valid, important evidence about a treatment in caring for your patient?

Do these results apply to your patient?

  1. Is your patient so different from those in the trial that its results can't help you?
    No. Patient in the scenario has a croup score 2-3, similar to patients in the trial. Assume baseline risk of hospital admission - 5%

How great would the potential benefit of therapy actually be for your individual patient?

  1. Method 1:
    1. Risk of the outcome in your patient, relative to patients in the trial. expressed as a decimal: 0.2
    2. NNT/f = 5/0.2 = 25
    3. NNT for patients like yours = 25
  2. Method 2:
    1 / (PEER x RRR)
    1. Your patient's expected event rate if they received the control treatment: PEER: 5%
    2. 1 / (PEER x RRR) = 1/.05x.85 = 24
    3. NNT for patients like yours = 24
  3. Method 3:
    1 /PEER-(PEER x Relative Risk)
    1. Your patient's expected event rate if they received the control treatment: PEER: 5%
    2. Relative Risk=EER/CER= 0.15
    3. 1/PEER-(PEERxRR) = 24
    4. NNT for patients like yours = 24

Are your patient's values and satisfied by the regimen and its preferences consequences?

  1. Do your patient and you have a clear assessment of their values and preferences?
    Consider inconvenience and cost of nebuliser versus hospital admissions saved.
  2. Are they met by this regimen and its consequences?
    Yes, probably

Additional Notes

The study includes a mix of mild to moderate croup. In primary care, mild cases will predominate and the treatment effect may differ. Caution in applying these results to primary care.

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