Cost-effectiveness of the IMPALA monitoring system for hospitalised children in low-resource settings: a pragmatic before-and-after study
Ângela Jornada Ben, Daniel Mwale, Pam Jansen, Owen Mtambo, Niek Versteegde, Eveline Geubbels, Job Calis, Jessica Chikwana, Jobiba Chinkhumba, Wendy JanssensBackground
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.