Cost-effectiveness of rapid, ICU-based, syndromic PCR in hospital-acquired pneumonia: analysis of the INHALE WP3 multi-centre RCT

Background: Hospital-acquired and ventilator-associated pneumonia (HAP and VAP) are pneumonias arising > 48 h after admission or intubation respectively. Conventionally, HAP/VAP patients are given broad-spectrum empiric antibiotics at clinical diagnosis, refined after 48–72 h, once microbiology results become available. Molecular tests offer swifter results, potentially improving patient care. To investigate whether this potential is realisable, we conducted a pragmatic multi-centre RCT (‘INHALE WP3’) of rapid, syndromic polymerase chain reaction (PCR) in ICU HAP/VAP compared with standard of care. As the use of molecular tests impact on hospital resources, it is important to consider their potential value-for-money to make fully informed decisions. Consequently, INHALE WP3 included an economic evaluation, presented here. Its aim was to estimate the cost-effectiveness of an in-ICU PCR (bioMérieux BioFire FilmArray Pneumonia Panel) in HAP/VAP, informing whether to implement such technology in routine NHS care.

Methods: We collected data on patient resource use and costs. These data were combined with INHALE WP3’s two primary outcome measures: antibiotic stewardship at 24 h and clinical cure at 14 days. Cost-effectiveness analyses were carried out using regression models adjusting for site. Sensitivity analyses explored assumptions and sub-group analyses explored differential impacts.

Results: We found lower total ICU costs (including PCR costs) in the intervention (PCR-guided therapy) group. Average costs were £40,951 for standard of care compared with £33,149 for the intervention group, a difference of − £7,802 (95% CI: − £15,696, £92). For antibiotic stewardship, the PCR-guided therapy was both less costly and more effective than routine patient management. For clinical cure, we did not find PCR-guided therapy to be cost-effective due to fewer cases being cured in the intervention group.

Conclusions: We found lower average ICU costs with the Pneumonia Panel. The pneumonia panel was cost-effective in terms of antibiotic stewardship, but not clinical cure.

Trial registration: Registered as ISRCTN16483855 on 5th August 2019.