Estimation of Relative Risk from Individually Matched Series

Point and interval estimation of relative risk is investigated for the purpose of casecontrol studies of disease etiology with individual matching of cases and controls. It is assumed that the disease is rare and that the relative risk bears no relatioln to the matching factors. The resulting maximum likelihood estimate is expressed in a closed form up to the case of two-to-one matching, while with 3 or more controls for each case a simple iterative procedure of obtaining the estimate is presented. Results for exact and approximate interval estimation are also derived.