Objective: The aim of this study was to explore heterogeneity in
the cost-effectiveness of high-flow nasal cannula (HFNC) therapy
compared with continuous positive airway pressure (CPAP)
in children following extubation.
Design: Using data from the FIRST-line support for Assistance
in Breathing in Children (FIRST-ABC) trial, we explore heterogeneity
at the individual and subgroup levels using a causal
forest approach, alongside a seemingly unrelated regression
(SUR) approach for comparison.
Settings: FIRST-ABC is a noninferiority randomized controlled
trial (ISRCTN60048867) including children in UK paediatric
intensive care units, which compared HFNC with CPAP as the
first-line mode of noninvasive respiratory support.
Patients: In the step-down FIRST-ABC, 600 children clinically
assessed to require noninvasive respiratory support were randomly
assigned to HFNC and CPAP groups with 1:1 treatment allocation
ratio. In this analysis, 118 patients were excluded because they
did not consent to accessing their medical records, did not consent
to follow-up questionnaire or did not receive respiratory support.

Measurements and Main Results: The primary outcome of this
study is the incremental net monetary benefit (INB) of HFNC
compared with CPAP using a willingness-to-pay threshold of
£20,000 per QALY gain. INB is calculated based on total costs
and quality adjusted life years (QALYs) at 6 months. The findings
suggest modest heterogeneity in cost-effectiveness of HFNC
compared with CPAP at the subgroup level, while greater heterogeneity
is detected at the individual level.
Conclusions: The estimated overall INB of HFNC is smaller than
the INB for patients with better baseline status suggesting that
HFNC can be more cost-effective among less severely ill patients.
Key Words: causal forest, cost-effectiveness, heterogenous effects,
machine learning

Title

Medical Care

Publisher

Lippincott Williams and Wilkins Ltd.

Publisher Country

United States of America

Indexing

Scopus

Impact Factor

3.081

Publication Type

Both (Printed and Online)

Volume

62

Year

2024

Pages

449-457