Find Positivity Threshold

This function calculates the positivity threshold based on various criteria.

Usage

find_pos(pos_thld, events, rand_ratio, hr_null, hr_alt, which_crit, targ)

Arguments

pos_thld

Numeric. The initial positivity threshold.

events

Numeric vector of length 2. The number of events at each analysis.

rand_ratio

Numeric. The randomization ratio.

hr_null

Numeric. The hazard ratio under the null hypothesis.

hr_alt

Numeric. The hazard ratio under the alternative hypothesis.

which_crit

Integer. The criterion to be used for finding the positivity threshold:

• 1: False positive / False negative equals required value.

• 2: False positive / (False negative + False positive) equals required value.

• 3: False positive equals required value.

• 4: Predictive probability equals required value.

targ

Numeric. The target value for the chosen criterion.

Value

Numeric. The calculated positivity threshold based on the specified criterion.

Examples

find_pos(
  pos_thld = 1.5,
  events = c(100, 200),
  rand_ratio = 1,
  hr_null = 1,
  hr_alt = 1.5,
  which_crit = 1,
  targ = 0.05
)
#> [1] 1.907371