The odds ratio and aggregate data: the 2x2 contingency table

The odds ratio remains one of the simplest of measures for quantifying the association structure between two dichotomous variables. Its use is especially applicable when the cell values of a 2 x 2 contingency table are known. However, there are cases where this information is not known. This may be due to reasons of confidentiality or because the data was not collected at the time of the study. Therefore one must resort to considering other means of quantifying the association between the variables. One strategy is to consider the aggregate association index (AAI) proposed by. This paper will explore the characteristics of the AAI when considering the odds ratio of the 2 x 2 contingency table.