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.