Computes incremental effect for all treatment strategies on outcome variables from a probabilistic sensitivity analysis relative to a comparator.

`incr_effect(x, comparator, sample, strategy, grp = NULL, outcomes)`

- x
A

`data.frame`

or`data.table`

containing simulation output with information on outcome variables for each randomly sampled parameter set from a PSA. Each row should denote a randomly sampled parameter set and treatment strategy.- comparator
The comparator strategy. If the strategy column is a character variable, then must be a character; if the strategy column is an integer variable, then must be an integer.

- sample
Character name of column denoting a randomly sampled parameter set.

- strategy
Character name of column denoting treatment strategy.

- grp
Character name of column denoting subgroup. If

`NULL`

, then it is assumed that there is only one group.- outcomes
Name of columns to compute incremental changes for.

A `data.table`

containing the differences in the values of each variable
specified in outcomes between each treatment strategy and the
comparator.

```
# simulation output
n_samples <- 100
sim <- data.frame(sample = rep(seq(n_samples), 4),
c = c(rlnorm(n_samples, 5, .1), rlnorm(n_samples, 5, .1),
rlnorm(n_samples, 11, .1), rlnorm(n_samples, 11, .1)),
e = c(rnorm(n_samples, 8, .2), rnorm(n_samples, 8.5, .1),
rnorm(n_samples, 11, .6), rnorm(n_samples, 11.5, .6)),
strategy = rep(paste0("Strategy ", seq(1, 2)),
each = n_samples * 2),
grp = rep(rep(c("Group 1", "Group 2"),
each = n_samples), 2)
)
# calculate incremental effect of Strategy 2 relative to Strategy 1 by group
ie <- incr_effect(sim, comparator = "Strategy 1", sample = "sample",
strategy = "strategy", grp = "grp", outcomes = c("c", "e"))
head(ie)
#> sample strategy grp ic ie
#> <int> <char> <char> <num> <num>
#> 1: 1 Strategy 2 Group 1 65827.82 2.516667
#> 2: 1 Strategy 2 Group 2 58907.17 2.247874
#> 3: 2 Strategy 2 Group 1 57389.52 2.139747
#> 4: 2 Strategy 2 Group 2 63251.77 2.711067
#> 5: 3 Strategy 2 Group 1 68718.28 3.708635
#> 6: 3 Strategy 2 Group 2 59492.99 2.150093
```