Description Usage Arguments Details Value Methods (by class) References Examples
Test on deviceevents using the Likelihood Ratio Test, originally proposed by Huang & Tiwari (2011). From the family of disproportionality analyses (DPA) used to generate signals of disproportionate reporting (SDRs).
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df 
Required input data frame of class

... 
Further arguments passed onto 
ts_event 
Required if Default: 
analysis_of 
Optional string indicating the English description of what
was analyzed. If specified, this will override the name of the
Default: Example: 
eval_period 
Required positive integer indicating the number of unique times counting in reverse chronological order to sum over to create the 2x2 contingency table. Default: Example: 
alpha 
Alpha or TypeI error rate in the range (0, 1), used to determine signal status. It is the threshold for determining if the observed reporting rate is greater than the expected based on Monte Carlo simulations of the null. Default: 
mc_sample 
Number of Monte Carlo samples for constructing the null distribution based on empirical data. Lowest recommended is 1000. Increasing iterations also increases pvalue precision. Default: 
This is an implementation of the "Regular LRT" per
Huang & Tiwari (2019). It assumes a test on a single event of interest
where all other events & devices are collapsed, effectively testing a 2x2
table only. Therefore this is a test on the significance of the likelihood
ratio instead of the maximum likelihood over i
events for a given
medical product j
(refer to Huang & Tiwari, 2011).
For parameter ts_event
, in the uncommon case where the
deviceevent count (Cell A) variable is not "nA"
, the name of the
variable may be specified here. Note that the remaining 3 cells of the 2x2
contingency table (Cells B, C, D) must be the variables "nB"
,
"nC"
, and "nD"
respectively in df
. A named character
vector may be used where the name is the English description of what was
analyzed. Note that if the parameter analysis_of
is specified, it will
override this name. Example: ts_event=c("Count of Bone Cement
Leakages"="event_count")
A named list of class mdsstat_test
object, as follows:
Name of the test run
English description of what was analyzed
Named boolean of whether the test was run. The name contains the run status.
A standardized list of test run results: statistic
for the test statistic, lcl
and ucl
for the set
confidence bounds, p
for the pvalue, signal
status, and
signal_threshold
.
The test parameters
The data on which the test was run
mds_ts
: LRT on mds_ts data
default
: LRT on general data
Huang L, Zalkikar J, Tiwari RC. A Likelihood Ratio Test Based Method for Signal Detection with Application to FDA’s Drug Safety Data. Journal of the American Statistical Association, 2011, Volume 106, Issue 496, 12301241.
Huang L, Zalkikar J, Tiwari RC. LikelihoodRatioTest Methods for Drug Safety Signal Detection from Multiple Clinical Datasets. Comput Math Methods Med. 2019, PMC6399568.
1 2 3 4 5 6 7 8 9  # Basic Example
data < data.frame(time=c(1:25),
nA=as.integer(stats::rnorm(25, 25, 5)),
nB=as.integer(stats::rnorm(25, 50, 5)),
nC=as.integer(stats::rnorm(25, 100, 25)),
nD=as.integer(stats::rnorm(25, 200, 25)))
a1 < lrt(data)
# Example using an mds_ts object
a2 < lrt(mds_ts[[3]])

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