A decision-tree model was used to map clinical pathways and synthesise evidence including patient data and case costing from a large teaching hospital in Ontario, Canada, and a selection of relevant published studies. The authors stated that the perspective was that of a Canadian public payer. The time horizon appeared to be lifetime.
The authors performed a review of the literature to obtain probabilities for the model parameters such as morbidity from exchange transfusion, high-risk infant visits, proportion of infants tested and emergency room and readmission visits. A selection of relevant studies was used for these parameters together with author assumptions (such as all infants would be tested and followed up according to the schedule). Pre-discharge treatment rates, reduction in hyperbilirubinaemia and the estimated reduction in kernicterus rates were the key clinical inputs. Survival from patients with cerebral palsy were fitted with a Gompertz function and used to approximate life expectancy for the population of neonates.
Monetary benefit and utility valuations:
Utilities were extracted from a publication about children with cerebral palsy in the absence of data for patients with kernicterus (see Other Publications of Related Interest).
Measure of benefit:
The measures of benefit used were cases of kernicterus prevented, life-years saved and quality-adjusted life years (QALYs).
Direct medical costs included bilirubin measurements, phototherapy, exchange transfusions, morbidity costs from exchange transfusions, follow-up visits, lifetime cost of kernicterus and hospital admissions for neonatal jaundice. Resource use was derived from various studies in the literature and London Health Sciences Centre, Ontario patient-level clinical data. Cost values employed unit costs from the 2008 Ontario Health Insurance Plan (see Other Publications of Related Interest). Prices were presented in Canadian dollars ($) for 2008.
Analysis of uncertainty:
The model parameters were examined with one-way and multi-way sensitivity analyses on key parameters such as treatment rates of the two strategies, kernicterus rate, reduction rate in kernicterus cases and bilirubin test costs. Sensitivity analyses were presented in tables for selected parameters.