print.expirest_osle: Print a summary of the shelf life estimation (osle)

Description

This is a method for the function print() for objects of class ‘expirest_osle’.

Usage

# S3 method for expirest_osle
print(x, ...)

Value

The ‘expirest_osle’ object passed to the x

parameter is returned invisibly.

Arguments

x: An object of class ‘expirest_osle’ returned by the expirest_osle() function.
...: Further arguments passed to or from other methods or arguments that can be passed down to the formatC() function.

Details

The function expirest_osle() estimates the shelf life, or retest period, following the ICH Q1E guideline. By default, batch poolability is checked as recommended by the guideline at a significance level of 0.25. Other levels can be used, although not recommended, by changing the default of the alpha_pool parameter. Three possible models may be appropriate, i.e.

a common intercept / common slope model (cics),
a different intercept / common slope model (dics) or
a different intercept / different slope model (dids).

The worst case intercept is the intercept of the batch whose confidence limit is the first crossing the acceptance limit. As in case of the cics model type all batches have a common intercept and a common confidence interval, all batches can be regarded as equally worst case. In case of the dids model type, shelf life estimation is done using the models obtained from fitting the data of each batch individually.

Examples

Run this code

# Fit models of different type
res1 <-
  expirest_osle(data = exp1[exp1$Batch %in% c("b2", "b5", "b7"), ],
                response_vbl = "Potency", time_vbl = "Month",
                batch_vbl = "Batch", sl = 95, sl_sf = 3,
                srch_range = c(0, 500), sf_option = "loose")
res2 <-
  expirest_osle(data = exp1[exp1$Batch %in% c("b3", "b4", "b5"), ],
                response_vbl = "Potency", time_vbl = "Month",
                batch_vbl = "Batch", sl = 95, sl_sf = 3,
                srch_range = c(0, 500), sf_option = "loose")
res3 <-
  expirest_osle(data = exp1[exp1$Batch %in% c("b4", "b5", "b8"), ],
                response_vbl = "Potency", time_vbl = "Month",
                batch_vbl = "Batch", sl = 95, sl_sf = 3,
                srch_range = c(0, 500), sf_option = "loose")

# The parameter settings sf_option = "loose" and ivl_side = "lower" (the
# default setting of ivl_side) cause the specification limit of 95.0
# (sl_sf = 3, i.e. 3 significant digits) to be reduced by 0.05, i.e. the
# actual specification limit is 94.95.

if (FALSE) {
  res1
  # Expected output of print(res1)
  # Summary of shelf life estimation following the ICH Q1E guideline
  #
  # The best model accepted at a significance level of 0.25 has
  # Common intercepts and Common slopes (acronym: cics).
  #
  # Worst case intercept: 100.5669 (Potency)
  # Worst case batch: NA
  # Estimated shelf life for cics model:  26.2241 (Month)
  #
  # Worst case intercepts, POIs and batches of all models
  # (Including information about the side where the confidence
  #   interval crosses the specification boundary):
  #           Intercept      POI  Side Batch
  # cics       100.5669  26.2241 lower    NA
  # dics       100.3638  24.8003 lower    b2
  # dids.pmse  100.7819 23.66724 lower    b5
  # dids       100.7819 23.34184 lower    b5

  res2
  # Expected output of print(res2)
  # Summary of shelf life estimation following the ICH Q1E guideline
  #
  # The best model accepted at a significance level of 0.25 has
  # Different intercepts and Common slopes (acronym: dics).
  #
  # Worst case intercept:   100.82 (Potency)
  # Worst case batch: b5
  # Estimated shelf life for dics model: 23.60194 (Month)
  #
  # Worst case intercepts, POIs and batches of all models
  # (Including information about the side where the confidence
  #   interval crosses the specification boundary):
  #           Intercept      POI  Side Batch
  # cics       102.0513 29.18093 lower    NA
  # dics         100.82 23.60194 lower    b5
  # dids.pmse  100.7819 22.49726 lower    b5
  # dids       102.3841 23.26251 lower    b3

  res3
  # Expected output of print(res3)
  # Summary of shelf life estimation following the ICH Q1E guideline
  #
  # The best model accepted at a significance level of 0.25 has
  # Different intercepts and Different slopes (acronym: dids).
  #
  # Worst case intercept: 101.2594 (Potency)
  # Worst case batch: b8
  # Estimated shelf life for dids model: 15.96453 (Month)
  #
  # Worst case intercepts, POIs and batches of all models
  # (Including information about the side where the confidence
  #   interval crosses the specification boundary):
  #           Intercept      POI  Side Batch
  # cics       101.5498 28.12518 lower    NA
  # dics       100.4882 22.47939 lower    b8
  # dids.pmse  101.2594 15.72348 lower    b8
  # dids       101.2594 15.96453 lower    b8
}