The cost-effectiveness of neonatal screening for Cystic Fibrosis: an analysis of alternative scenarios using a decision model

Table 1 Model parameters, data sources and values used in the model.

Probabilities
Variable	Base case value	Range used in sensitivity analysis
Incidence of cystic fibrosis [2]	0.0004	0.00067 – 0.00029
% diagnosed at birth (MI & family history) [39]	0.15	0.10 – 0.40
IRT test sensitivity [40]	0.9	0.99
IRT test specificity [40]	0.995	0.999
DNA test: % of mutations detected [40]	0.88	0.85 – 0.95
DNA test sensitivity [40]	0.9856	0.9975
DNA test specificity^a	1.0
Increased annual transition probability of remaining without symptoms (in early-diagnosed cases)^b	10%	10 – 40%

^a It is assumed that there are no false positives (from the combined DNA and sweat tests), because all test results that are either homozygous or heterozygous for cystic fibrosis mutations, are confirmed using sweat tests.
^b Assumed effect of early diagnosis

ISSN: 1478-7547