safestats (version 0.8.7)

computeConfidenceBoundForLogOddsTwoProportions: Estimate an upper or lower bound for a safe confidence sequence on the logarithm of the odds ratio for two proportions.

Description

Estimate an upper or lower bound for a safe confidence sequence on the logarithm of the odds ratio for two proportions.

Usage

computeConfidenceBoundForLogOddsTwoProportions(
  ya,
  yb,
  safeDesign,
  bound = c("lower", "upper"),
  deltaStart,
  deltaStop,
  precision
)

Value

numeric: the established lower- or upper bound on the logarithm of the odds ratio between the groups

Arguments

ya

positive observations/ events per data block in group a: a numeric with integer values between (and including) 0 and na, the number of observations in group a per block.

yb

positive observations/ events per data block in group b: a numeric with integer values between (and including) 0 and nb, the number of observations in group b per block.

safeDesign

a 'safeDesign' object obtained through designSafeTwoProportions

bound

type of bound to calculate; "lower" to get a lower bound on positive delta, "upper" to get an upper bound on negative delta.

deltaStart

starting value of the grid to search over for the bound on the confidence sequence (in practice: the interval). Numeric >0 when searching for a lower bound, numeric < 0 when searching for an upper bound.

deltaStop

end value of the grid to search over for the bound on the confidence sequence (in practice: the interval). Numeric >0 when searching for a lower bound, numeric < 0 when searching for an upper bound.

precision

precision of the grid between deltaStart and deltaStop.

Examples

balancedSafeDesign <- designSafeTwoProportions(na = 1,
                                               nb = 1,
                                               nBlocksPlan = 10,
                                               alpha = 0.05)
#hypothesize OR < 1 (i.e., log OR < 0)
ya <- c(1,1,1,1,1,1,1,1,0,1)
yb <- c(0,0,0,0,1,0,0,0,0,0)
#one-sided CI for OR-, establish upper bound on log odds ratio
computeConfidenceBoundForLogOddsTwoProportions(ya = ya,
                                           yb = yb,
                                           safeDesign = balancedSafeDesign,
                                           bound = "upper",
                                           deltaStart = -0.01,
                                           deltaStop = -4,
                                           precision = 20)