A cost-effectiveness analysis of selective decontamination of the digestive tract in mechanically ventilated patients in the intensive care unit

Objective To evaluate the 24-months cost-effectiveness of selective decontamination of the digestive tract (SDD) versus standard care in mechanically ventilated Intensive Care Unit (ICU) patients. Design Within‑trial cost‑effectiveness analysis using linked administrative healthcare datasets. Setting Nineteen Australian ICUs participating in the Australian Selective Decontamination of the Digestive Tract in the ICU (SuDDICU Australia) cluster crossover randomised trial (2018–2021). Participants 2845 adult patients enrolled from New South Wales, Australia with 24‑month follow‑up (SDD, n=1252; standard care, n=1593). Interventions SDD plus standard care versus standard care alone. Main Outcome measures All‑cause mortality at 24 months; life‑years gained; healthcare resource use; healthcare costs (Australian dollars [A$]) and cost-effectiveness expressed as incremental cost-effectiveness ratio (cost per life-year gained); subgroup analyses in acute brain injuries/conditions patients. Results At 24 months, mortality (SDD: 521/1252 [41.6%] vs standard care: [697/1593] 43.8%; p=.25), and survival probabilities (hazard ratio 0.93, 95% confidence interval: 0.83-1.04; p=.22) did not differ between groups. SDD was associated with shorter median mechanical ventilation duration (4.0 vs 4.3 days) and lower mean non-SDD antibiotics use (11.7 vs 12.9) versus standard care. Mean per-patient healthcare costs were higher with SDD (A$294,529 vs A$268,493), yielding an incremental cost-effectiveness ratio of A$669,726 per life-year gained and ∼1% probability of SDD being cost-effectiveness at the Australian willingness-to-pay threshold. Incremental cost-effectiveness ratio was lower in traumatic brain injury patients (A$169,887 per life-year gained). Conclusion In mechanically ventilated ICU patients, SDD use didn’t improve 24-month survival and healthcare costs were higher, resulting in low probability of cost-effectiveness within Australian healthcare context.