OpenVigil - 2x2 contingency table calculator
Version 2016-07-07, firstname.lastname@example.org
The calculations of the pharmacovigilance measurements of disproportionality have been successfully validated against R/epiR.
A free online statistical calculator for a contingency table that has 2 rows and 2 columns for the two categorial data to be analyzed. This software is especially designed for pharmacovigilance data but might be useful for other data as well.
These measurements of disproportionality are calculated as RRR=DE*N/(D*E), PRR=(DE/D)/(dE/d) and ROR=DE*de/(De*dE). A value of 1 is considered normal background noise. The confidence interval can be estimated using Chi-squared with Yates' correction chisq > 4 or lower bound of the 95% confidence interval (CI) of RRR, PRR or ROR, e.g. for s = sqr( 1/DE + 1/De + 1/dE + 1/de ) for ROR with CI = e ^ ( ln ROR ± 1,96s ).
- Chi-squared values corrected as recommended by Yates (chisq),
- basic statistical measurements of disproportionality for like RRR, ROR, PRR and diagnostic statistic's measurements like Likelihood Ratios (LR+,LR-) and Pos/Neg Predictive Values
- optional correction for real-world background,
(e.g., prevalence data of drug usage or event/disease occurrence in the common population),under-reportingand confounders/tied values for number of records.