twsa: Two-way sensitivity analysis using linear regression metamodeling

Description

This function displays a two-way sensitivity analysis (TWSA) graph by estimating a linear regression metamodel of a PSA for a given decision-analytic model

Usage

twsa(
  sa_obj,
  param1 = NULL,
  param2 = NULL,
  ranges = NULL,
  nsamp = 100,
  outcome = c("eff", "cost", "nhb", "nmb", "nhb_loss", "nmb_loss"),
  wtp = NULL,
  strategies = NULL,
  poly.order = 2
)

Value

twsa A ggplot2 object with the TWSA graph of param1 and param2 on the outcome of interest.

Arguments

sa_obj: sensitivity analysis object; either a probabilistic sensitivity analysis (make_psa_obj) or a deterministic sensitivity analysis object (run_owsa_det)
param1: String with the name of the first parameter of interest
param2: String with the name of the second parameter of interest
ranges: a named list of the form c("param" = c(0, 1), ...) that gives the ranges for the parameter of interest. If NULL, parameter values from the middle 95 from this range is determined by nsamp.
nsamp: number of samples from ranges
outcome: either effectiveness ("eff"), cost ("cost"), net health benefit ("nhb"), net monetary benefit ("nmb"), or the opportunity loss in terms of NHB or NMB ("nhb_loss" and "nmb_loss", respectively). "nmb_loss_voi" and "nhb_loss_voi" are only used in internal function calls of metamodel within other VOI functions.
wtp: if outcome is NHB or NMB (or the associated loss), must provide the willingness-to-pay threshold
strategies: vector of strategies to consider. The default (NULL) is that all strategies are considered.
poly.order: order of polynomial for the linear regression metamodel. Default: 2