Parameter Values Incorporated Into Probabilistic Sensitivity Analysis to Estimate Net Present Value Cost Savings of iBASIS–Video Interaction to Promote Positive Parenting vs Usual Care
autism spectrum disorder, Disability
POSITIVE, INTERACTION
Abbreviations: ASD, autism spectrum disorder; CL, confidence limit; DD, developmental delay; iBASIS-VIPP, iBASIS–Video Interaction to Promote Positive Parenting; NA, not applicable; NDIS, National Disability Insurance Scheme; RCT, randomized clinical trial; TAU, treatment as usual.Support costs for eligible children with DD occur up to their seventh birthday as per the Australian NDIS. Beyond that age, a child may be eligible under an alternate disability category, but such uncertainty modeling was not considered appropriate for this study.Noting NDIS costs from published annual payments of A $15 640 (US $10 995) per child at ages 7 to 14 years and A $28 800 (US $20 247) per child at ages 15 to 18 years (Table 1).Alternate values for iBASIS-VIPP and TAU costs were not modeled because an alternate (lower or higher) cost would mean a different clinical service and as such would potentially impact outcomes and costs and outcomes must be considered together.Assumed value (considered plausible based on expert opinion).Category of DD was not diagnostic, but rather included children with some features of ASD, not meeting a threshold for an ASD diagnosis. As such, not all of these children would be eligible for (or need) government supports through the NDIS. Therefore, 50% was taken as a reasonable best estimate drawing on expert opinion on knowledge of these children and NDIS eligibility. In sensitivity analysis, it was assumed that 100% of these children would receive supports.We conducted 1-way sensitivity analyses, reporting the individual effect of modifying each parameter in turn. We also conducted probabilistic sensitivity analysis, describing the combined impact of adjusting all model parameter values simultaneously on NPV cost. In the probabilistic analysis, results are expressed as the percent likelihood that iBASIS-VIPP would be cost saving or achieve any specified cost-savings threshold. Modeling of base-case estimates and 1-way sensitivity analysis was conducted in Excel, version 2302 (Microsoft). Probabilistic sensitivity analysis was performed in TreeAge Pro, version R1.0 (TreeAge Software). Data analysis was conducted from July 1, 2021, to January 29, 2023. The modeling was based on a 2-tailed, 5% 