Cost-effectiveness of the IMPALA monitoring system for hospitalised children in low-resource settings: a pragmatic before-and-after study.

BACKGROUND: Staff shortages, limited training and inadequate hospital equipment often delay responses to patient deterioration in low-resource settings. The IMPALA continuous monitoring system was developed to support proactive care for critically ill children in such settings. This study evaluated IMPALA cost-effectiveness compared with current practice manual intermittent monitoring from provider and societal perspectives. METHODS: We conducted an economic evaluation based on a before-and-after cohort of children (0-180 months) admitted to Zomba Central Hospital (ZCH) and St. Luke's Hospital (SLH), Malawi (2022-2024), where IMPALA was implemented in high-dependency units (HDUs). Targeted maximum likelihood estimation assessed percentage point (pp) differences in mortality, critical illness events (CIEs), disability-adjusted life years (DALYs) and costs (medical, non-medical, indirect). Incremental cost-effectiveness ratios (ICERs) and cost-effectiveness probabilities were calculated for different willingness-to-pay thresholds. RESULTS: At ZCH paediatric ward, 1840 pre-IMPALA and 6255 post-IMPALA children were included; 248 and 736 were admitted to the HDU. Ward mortality decreased (from 3.8% to 2.8%), with an adjusted 1.9 pp reduction (95% CI -3.8 to -0.6). At ZCH-HDU, mortality slightly increased (from 8.1% to 9.0%), but IMPALA was associated with an adjusted 9.8 pp reduction (95% CI -26.5 to 5.0), a 47.1 pp decrease in CIEs (95% CI -52.9 to -41.8), and 5.4 DALYs averted (95% CI -14.2 to 3.1). At SLH paediatric ward, 930 pre-IMPALA and 1126 post-IMPALA children were included. Mortality in SLH decreased (from 4.0% to 2.1%), with an adjusted 1.6 pp reduction (95% CI -3.2 to -0.2), a 25.5 pp decrease in CIEs (95% CI -30.1 to -20.9) and 1.0 DALYs averted (95% CI -1.9 to -0.1). Provider and societal costs decreased in both wards, but not in the HDU. IMPALA was dominant in wards and slightly more costly but more effective in the HDU (ICERs -$22.5-$0.4 per life saved). Cost-effectiveness probabilities ranged from 0.8 to 1.0 in wards and 0.3-1.0 in the HDU. CONCLUSION: IMPALA was highly cost-effective, reducing mortality by >40%, morbidity by >50%, increasing DALYs averted, shortening hospital stays and lowering costs, with spillover benefits from HDUs to wards.