OpenVigil - 2x2 contingency table calculator

Version 2016-07-07,
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.
Capabilities: 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 ).

Fill in at least 4 fields with numbers and hit the button below to calculate the most common measurements of disproportionality used in pharmacovigilance in your 2x2 contingency table.

Predictor/Event GroupsExposed/Biomarker pos/Drug usedNot exposed/Biomarker neg/Other drugsSums
Event/Disease occurredDE dE E
Other events/no disease occurredDe de e
SumsD d N

Optionally, you can adjust these numbers to the real-world situation:
Adjust for disease prevalence
Leave 0 (no adjustment) or enter the prevalence of the event/disease as fraction, e.g., 0.00001 for 1:100,000
Adjust for under-reporting
Leave 0 (no adjustment) or enter estimated fraction of filed reports of non-filed, e.g., 0.01 for 1:100