Forms designs for sets of n-of-1 trials (S.J. Senn & R.W. Payne).
Options
PRINT = string tokens |
Controls printed output (design, factors); default desi |
NSUBJECTS = scalars |
Specifies the number of subjects |
NCYCLES = scalars |
Specifies the number of cycles |
Parameters
TREATMENTS = pointers |
Treatment factor |
SUBJECTS = factors |
Subject factor |
CYCLES = factors |
Cycles factor |
PERIODS = factors |
Periods factor |
PAIRS = factors |
Pairs factor |
SEED = factors |
Seed to be used to randomize each design; a negative value implies no randomization |
Description
An n-of-1 trial is a medical trial in a single subject to compare two treatments. The design consists of “cycles” of pairs of periods to which the treatments are allocated in one of the two possible orders. For a set of n-of-1 trials, several subjects (or patients) receive cycles of treatments over a sequence of periods.
The SUBJECTS and the PERIODS parameters save factors identifying the subjects and the periods, and the CYCLES parameter saves a factor indexing the cycles within each subject. Alternatively, the PAIRS parameter can save a factor indexing the pairs of periods (i.e. the cycles) across the whole design. PAIRS thus represents the combinations of the CYCLES and PAIRS factors. The TREATMENTS parameter saves a factor containing the treatment allocations.
The NSUBJECTS option can specify the number of subjects. This can be omitted if the SUBJECTS factor has already been defined with its number of levels. Similarly, the NCYCLES option can specify the number of cycles, and can be omitted if the CYCLES factor has already been defined with its number of levels.
The PRINT option controls printed output, with settings:
IDEAL project and completed when working on the National Institute for Health and Care Research (NIHR) DIAMOND project. Support from both is gratefully acknowledged as is collaboration with Artur Araujo, Robin Chatters, Andrew Cooke, Liv Hawksworth, Steven Julious and Sonia Leite.
Options: PRINT, NSUBJECTS, NCYCLES
Parameters: TREATMENTS, SUBJECTS, CYCLES, PERIODS, PAIRS, SEED.
See also
Procedures: N1ANOVA, N1PLOT, N1SIMULATE, N1TEST
GenStat Reference Manual 1 Summary section on: Design of experiments.
Example
CAPTION ''N1DESIGN example'; STYLE=meta
N1DESIGN [PRINT=design; NCYCLES=3; NSUBJECTS=12] SUBJECT=Subject;\
TREATMENT=Treatment; CYCLE=Cycle; PERIOD=Period; PAIR=Pair;\
SEED=241015
PRINT Subject,Cycle,Pair,Period,Treatment