openqalyregimen

Overview

The openqalyregimen package provides a declarative interface for defining treatment regimens and calculating medication costs. It handles a wide range of cases including:

• Dosing per patient, per m2 of BSA, or per kg of weight, with optional averaging over a patient distribution of BSA or weight
• One costing model for every product (tablets, vials and other units): the cheapest units covering the dose, exact whole-unit doses, dose rounding against the prescribed dose, or a no-wastage scenario
• Drug cost recorded per administration or per dispensing, with separate administration and dispensing fees
• Handling of loading doses, dose escalation, and sequencing
• Correctly attributes all costs to the model cycle schedule, even when medication cycles do not align with model cycles
• Extensive debugging output to ensure transparency
• Out of the box compatability with openqaly models, but can also be used independently

Installation

# Install the development version from GitHub
remotes::install_github("PolicyAnalysisInc/openqalyregimen")

Basic Example

library(openqalyregimen)

reg <- define_regimen(
  name = "Capecitabine",
  route = "oral",
  dose_per_admin = 2000,
  dose_basis = "bsa",
  patient_bsa = 1.8,
  patient_bsa_sd = 0.2,
  med_cycle_length = 21,
  admin_days = 1:14,
  max_med_cycles = 4,
  unit_size = c(150, 500),
  unit_cost = 2.21,
  exact = FALSE,
  charge_timing = "per_dispensing",
  dispensing_cost = 45
)

calculate_med_costs(
  reg,
  model_cycle_length = 21,
  n_cycles = 4
)
#>   cycle cycle_start_day cycle_end_day n_administrations n_dispensings drug_cost
#> 1     1               0            21                14             1  238.2382
#> 2     2              21            42                14             1  238.2382
#> 3     3              42            63                14             1  238.2382
#> 4     4              63            84                14             1  238.2382
#>   admin_cost dispensing_cost total_cost
#> 1          0              45   283.2382
#> 2          0              45   283.2382
#> 3          0              45   283.2382
#> 4          0              45   283.2382

Because the dose is averaged over a BSA distribution, this example uses exact = FALSE: for each BSA the cheapest tablets covering the dose are costed. Exact whole-tablet dosing (exact = TRUE) needs a fixed dose.

Learn more

The package vignettes cover:

• Oral regimens
• IV and injection regimens
• Combinations, loading doses, and phase changes
• Use inside an openqaly model

License

Copyright (C) 2026 Avalere Health. Licensed under the GNU General Public License v3.0; see LICENSE.md.