1294 cases and 4469 controls were included. 1010 cases (781%) had MMR vaccination recorded before diagnosis, compared with 3671 controls (821%) before the age at which their matched case was diagnosed. After adjustment for age at joining the database, the odds ratio for association between MMR and pervasive developmental disorder was 086 (95% CI 068-109). Findings were similar when restricted to children with a diagnosis of autism, to those vaccinated with MMR before the third birthday, or to the period before media coverage of the hypothesis linking MMR with autism.

1. Calculate the measure of association for each study after completing the 2x2 table and interpret the measure of association?