Aim: To estimate the societal costs of obstructive sleep apnoea syndrome (OSAS) in New Zealand and develop a simulation tool to evaluate treatment options.
Method: Treatment profiles, availability, uptake, and costs were based on services in the Wellington Region, and were used to develop a decision analytic model with micro costing of each potential outcome. Sensitivity analyses were conducted with 10,000 Monte Carlo simulations randomly varying each model parameter between high and low estimates.
Results: Total annual societal costs of OSAS for New Zealanders aged 30-60 years were estimated at $40 million (range $33-$90 million) or $419 per case, with accidents being the major contributor. This included 58% direct medical, 13% direct non-medical, 25% indirect, and 3% intangible costs. The estimated incremental net cost of treating OSAS was $389 per case treated (range $338-$427). The estimated incremental net direct medical cost per quality of life year (QALY) gained was $94 (range $56-$310).
Conclusion: The estimated incremental direct medical cost per QALY gained by OSAS treatment is well below the average QALY cost ($6865) for drugs selected by PHARMAC to receive government subsidy for use in the healthcare system. Thus, the analysis strongly supports the cost effectiveness of OSAS treatment.