Cost-effectiveness of molecular point-of-care testing for influenza viruses in elderly patients at ambulatory care setting

BACKGROUND Early initiation of antiviral therapy in elderly patients with influenza is associated with reduced risk of extra clinic visit, hospitalization and death. This study examined the cost-effectiveness of molecular POCT for detection of influenza viruses in Hong Kong elderly patients with influenza-like illness (ILI) in the outpatient clinics. METHODS A decision analytic model was used to simulate outcomes of a hypothetical cohort of elderly patients presented with ILI at outpatient clinics during peak season of influenza with two diagnostic approaches: Rapid molecular assay (POCT-PCR group) and clinical judgement with no POCT. Outcome measures included influenza-associated direct medical cost, hospitalization and mortality rates, quality-adjusted life year loss (QALY loss), and incremental cost per QALY saved (ICER). RESULTS In base-case analysis, POCT-PCR group was expected to reduce hospitalization (1.38% versus 2.85%) and mortality rate (0.08% versus 0.16%) and save 0.00112 QALYs at higher cost (by USD33.2 per ILI patient), comparing with clinical judgement group. The ICER of POCT-PCR was 29,582 USD/QALY saved. One-way sensitivity analyses found ICER sensitive to: Hospitalization rate without prompt antiviral therapy; odds ratio of hospitalization with prompt therapy; influenza prevalence; patient age and mortality rate of hospitalized patients. POCT-PCR was cost-effective in 60.6% and 99.4% of 10,000 Monte Carlo simulations at willingness-to-pay threshold of 1x and 3x gross domestic product per capita of Hong Kong, respectively. CONCLUSIONS Molecular POCT for influenza detection in elderly patients with ILI at outpatient clinics during peak influenza season appeared to be cost-effective in Hong Kong.