Page 66 - 16Neonatal Jaundice_compressed

Introduction

If bilirubin concentrations were presented as mg/dl, these were converted to the SI unit
micromol/litre by multiplying by 17.1.
Where data were missing, typically standard deviations of change scores, these were imputed
using a standard formula as recommended in Section 16.1.3.2 of the Cochrane Handbook
(www.cochrane-handbook.org/):


SD E,change  SD 2 E,baseline  SD 2 E,final    2 Corr SD E,baseline  SD E,final 
Instead of calculating a correlation coefficient for each individual study, it was decided to use a
correlation of 0.80 as an arbitrary cut-off value.
The number needed to treat (NNT) was calculated with the following formula:

Table 2.5 ‘2 x 2’ table for calculation of number needed to treat (NNT)
Outcome present Outcome absent
Treated A C
Control B D

1
NNT 
 
A   A B CC D 

Health economics

The aim of the economic input in this guideline was to inform the GDG of potential economic
issues relating to neonatal jaundice, and to ensure that recommendations represented a cost-
effective use of scarce resources.
The GDG sought to identify relevant economic evidence for this guideline, but no published
evidence was identified that fully answered the guideline questions. Had any such evidence
been identified, it would have been assessed using a quality assessment checklist based on good
practice in decision-analytic modelling (because no standard system of grading the quality of
economic evaluations exists).
Where it is not possible to make recommendations based on published economic evidence, the
guideline health economist may undertake de novo economic analysis. Health economic
analysis may be required for a clinical question where there are genuine competing alternatives
for decision-makers that may have implications for healthcare resources and patient outcomes.
Cost-effectiveness analysis can provide clarity as to which alternative is currently the best option
for the NHS.
After GDG discussion of the clinical questions it became apparent that economic analysis
would not actually influence the recommendations as originally expected, since genuine
alternatives to current practice did not practically exist in the NHS. For example, ‘no treatment’
would not be considered as a serious alternative to phototherapy or exchange transfusion in any
modern healthcare system.
Therefore, the remaining areas where health economics was thought to be important in guiding
recommendations was around testing for hyperbilirubinaemia and the use of intravenous
immunoglobulin (IVIG). The results of the economic analyses are summarised briefly in the
guideline text (Sections 5.2 and 7.4, respectively). A more detailed description of the health
economic methods and results are presented in Appendices C and D, respectively.

GDG interpretation of the evidence and formulation of recommendations
For each clinical question, recommendations for clinical care were derived using, and linked
explicitly to, the evidence that supported them. In the first instance, informal consensus
methods were used by the GDG to agree clinical evidence statements. Statements summarising
the GDG’s interpretation of the clinical and economic evidence and any extrapolation

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