Completed Therapy Worksheet for Evidence-Based Neonatal Medicine
Citation
The Neonatal Inhaled Nitric Oxide Study Group. Inhaled nitric oxide in full-term and nearly full-term infants with hypoxic respiratory failure. N Engl J Med 1997; 336: 597-604.
Are the results of this single preventive or therapeutic trial valid?
-
Was the assignment of patients to treatments randomised?
And was the randomisation list concealed? -
Yes. Central telephone randomisation was used.
Were all patients who entered the trial accounted for at its conclusion? -
And were they analysed in the groups to which they were randomised?
Yes to both questions. -
Were patients and clinicians kept "blind" to which treatment was being received?
Yes. Designated individuals who were not involved in the clinical care adjusted and monitored the study gases. -
Aside from the experimental treatment, were the groups treated equally?
Yes. -
Were the groups similar at the start of the trial?
Yes.
Are the valid results of this randomised trial important?
Your calculations:
| Event rate for primary outcome (death by 120 days of age or initiation of ECMO) | Relative Risk Reduction RRR |
Absolute Risk Reduction ARR |
Number Needed to Treat NNT |
|
|---|---|---|---|---|
| CER | EER | (CER - EER)/CER | CER - EER | 1/ARR |
| 64% | 46% | 28% | 18% | 6 |
Further analyses demonstrated that inhaled nitric oxide reduced the need for ECMO but did not decrease mortality: CER 55%, EER 39%, RRR 29%, ARR 16%, NNT 7 (95% CI 4 to 31).
Can you apply this valid, important evidence about a treatment in caring for your patient?
Do these results apply to your patient?
-
Is your patient so different from those in the trial that its results can't help you?
No.
How great would the potential benefit of therapy actually be for your individual patient?
-
Method I: f
Risk of the need for ECMO in your patient, relative to patients in the trial. Expressed as a decimal: 1
NNT/f
= 7 / 1
= 7
(NNT for patients like yours) -
Method II: 1 / (PEER x RRR)
Your patient's expected event rate if they received the control treatment: PEER:______
1 / (PEER x RRR)
= 1/________
= __________
(NNT for patients like yours)
Are your patient's values and preferences satisfied by the regimen and its consequences?
-
Do your patient and you have a clear assessment of their values and preferences?
This needs to be discussed with the parents of the patient; however, since inhaled nitric oxide is far less invasive than ECMO, chances are that parent would accept a recommendation to try inhaled nitric oxide first. -
Are they met by this regimen and its consequences?
Likely.
Additional Notes
See commentary with the abstract in Evidence Based Medicine Sept/Oct. 1997 page 153

