
The goal of ‘dynamicpv’ is to provide a simple way to calculate (net) present values and outputs from health economic models (especially cost-effectiveness and budget impact) in discrete time that reflect dynamic pricing and dynamic uptake.
Dynamic pricing is also known as life cycle pricing; dynamic uptake is also known as multiple or stacked cohorts, or dynamic disease prevalence. Shafrin (2024) provides an explanation of dynamic value elements, in the context of Generalized Cost Effectiveness Analysis, and Puls (2024) reviews challenges of incorporating such dynamic value elements. This package aims to reduce those challenges.
Through the dynpv() function, the package provides calculations of the present values of costs, life years, QALYs or other payoffs allowing for dynamic uptake and dynamic pricing. The starting point is a conventional cohort cost-effectiveness model, such as one computed using the heemod package.
The package should shortly be available on CRAN. Installing from here is simplest, once available.
# CRAN installation - when available
install.packages("dynamicpv")
You can install the development version of dynamicpv from GitHub as follows.
# Install devtools package if not already installed
install.packages("devtools")
# Install dynamicpv using pak from MSD repository
pak::pak("MSDLLCpapers/dynamicpv")
Note that the above does not install vignettes. Vignettes may be viewed on the package website or by instead running the following.
devtools::install_github("MSDLLCpapers/dynamicpv", build_vignettes=TRUE)
You should then load the package, alongside some other packages used here.
# Load the dynamicpv package
library(dynamicpv)
# Recommended others
library(dplyr)
library(heemod)
library(ggplot2)
library(tidyr)
There are four vignettes provided.
The Mathematical
Framework
vignette (vignette("math-framework")) describes the motivation and
mathematical framework behind this package.
The Net Present
Value
vignette (vignette("net-present-value")) describes how the package
can be used to derive Net Present Values of simple cashflows with
dynamic pricing and/or dynamic uptake.
The Cost-Effectiveness
Applications
(vignette("cost-effectiveness-applications")) vignette describes
how, given a static cost-effectiveness model (single cohort, prices
constant in real terms), Incremental Cost-Effectiveness Ratios may
be calculated that allow for dynamic pricing and/or dynamic uptake.
This is illustrated by taking an example three-state partitioned
survival model of a new intervention for an oncology indication
compared to standard of care, with stated assumptions for how
pricing and uptake may be dynamic. Nominal and Real ICERs are
plotted over time, illustrating the impact of the loss of
exclusivity points for each intervention.
The Budget Impact
Applications
(vignette("budget-impact-applications")) vignette describes how,
given a static cost-effectiveness model (single cohort, prices
constant in real terms) and dynamic uptake, a budget impact can be
readily calculated. The calculations are repeated with the dynamic
pricing assumptions to illustrate how easily this can be done, and
examine the differences between a budget impact assessment with and
without dynamic pricing.
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.