Check a Randomisation List at Unblinding

Checks that a list from ralloc() is the one committed to before enrolment, and that the stated procedure and seed produce exactly it.

Usage

rallocvrf(x, digest = NULL, seed = NULL)

Arguments

x

A list from ralloc() (kept with saveRDS()).

digest

The commitment published before enrolment, or NULL to check against the one in x.

seed

The seed revealed at unblinding, or NULL for the one in x.

Value

An object of class rmbl_alloc_check: a list with ok (all checks passed) and checks (a data frame of check, ok and detail). It prints as a box that opens with VERIFIED or NOT VERIFIED.

Details

Three checks: the list's own commitment, recomputed from its rows, settings and seed, equals digest (the value signed and timestamped before enrolment; without it, the commitment stored in the list); the list regenerates row for row from the seed and the settings; and every participant id is there once. A list edited after the commitment fails the first; a list that does not come from its seed (one chosen among many, or written by hand) fails the second.

Errors: x that does not come from ralloc().

See also

ralloc()

Examples

a <- ralloc(20, seed = "teaching example")
commitment <- attr(a, "alloc")$digest
rallocvrf(a, digest = commitment)
#> ╭── Randomisation list: verified ─────────────────────────────────────────────╮
#> │ ✔ VERIFIED  · 3 of 3 checks passed                                          │
#> │                                                                             │
#> │   ✔    commitment    the list is the one committed to                       │
#> │   ✔    seed          the seed and the settings give this list, row for row  │
#> │   ✔    participants  20 participants, each once                             │
#> │        commitment    97deda0c79a09567bd30d89449cd182c382304150cc976fc1de12f │
#> │                      0f183c3cc3                                             │
#> ╰─────────────────────────────────────────────────────────────────────────────╯

# one allocation changed after the commitment
b <- a
b$arm[3] <- if (b$arm[3] == "A") "B" else "A"
rallocvrf(b, digest = commitment)
#> ╭── Randomisation list: NOT verified ─────────────────────────────────────────╮
#> │ ✖ NOT VERIFIED  · 2 of 3 checks failed                                      │
#> │                                                                             │
#> │   ✖    commitment    the list, its settings or the seed differ from the     │
#> │                      commitment                                             │
#> │   ✖    seed          the seed and the settings give a different list        │
#> │   ✔    participants  20 participants, each once                             │
#> │        commitment    a95ccc06c95d7701d2391bc5746e9dad7286181a58ab25b06d8c01 │
#> │                      f5230d2c03                                             │
#> ╰─────────────────────────────────────────────────────────────────────────────╯

# a different seed revealed at unblinding
rallocvrf(a, digest = commitment, seed = "another seed")
#> ╭── Randomisation list: NOT verified ─────────────────────────────────────────╮
#> │ ✖ NOT VERIFIED  · 2 of 3 checks failed                                      │
#> │                                                                             │
#> │   ✖    commitment    the list, its settings or the seed differ from the     │
#> │                      commitment                                             │
#> │   ✖    seed          the seed and the settings give a different list        │
#> │   ✔    participants  20 participants, each once                             │
#> │        commitment    6a8c779fdf6e44d8e52ce53cba102c74cd00af2d70620be49d19ef │
#> │                      a8c1c9f3a1                                             │
#> ╰─────────────────────────────────────────────────────────────────────────────╯