Aims: In advanced Parkinson's disease (aPD), adequate 24-hour control of OFF-time may not be achievable using oral/transdermal therapies. Clinical trials of foslevodopa/foscarbidopa (LDp/CDP) demonstrate meaningful reductions in OFF-time and OFF-related sleep disturbance in aPD. Previous analyses have only considered direct medical costs: this analysis considers a broader societal perspective (direct non-medical costs, informal care, loss of earnings, productivity, and tax).
Methods: Inputs for the societal impact model were taken from a cost-utility model comparing LDp/CDp with best medical treatment (BMT), accepted by the UK National Institute of Health and Care Excellence (NICE). Quintiles of normalized OFF-time across a 16-hour waking day in each treatment group were applied to literature-based estimates for direct medical, non-medical, and indirect costs. The resulting state-specific cost estimates were applied to the modelled aPD patient population.
Results: The model estimates the potential UK population for LDp/CDp at 17,505. Continuous 24-hour delivery of LDp/CDp results in greater time spent in OFF-time states 0-1 (0-4 hours of OFF-time/16-hour waking day) vs BMT alone. Net savings if all eligible patients receive LDp/CDp are £79.1 M in year 1, £235.4 M in year 2, rising to £262.2 M in year 3, declining to £222.9 M in year 4 and £153.7 M in year 5 as disease progresses and the efficacy of LDp/CDp declines. The estimated total net savings are £953 M after 5 years. Results are robust in scenario analyses (excluding costs of excessive sleepiness, earnings loss, productivity, and tax loss).
Limitations: A NICE-accepted model was used as the economic modelling basis for the societal impact model, however, much of the data was derived from Adelphi datasets, with the potential for inconsistent definitions.
Conclusion: When considered from a societal perspective, the use of LDp/CDp in aPD patients inadequately controlled on oral therapy is associated with net healthcare and societal annual savings of over £79.1 M vs BMT.
Keywords: I; I00; I1; I19; Parkinson’s disease; costs; foslevodopa/foscarbidopa; indirect costs; societal impact.