Epidemiological studies assessing the association between SSRIs exposure and the occurrence of upper GI bleeding.

aFor the purpose, a retrospective study is when the idea for the study was developed after data collection; the opposite is termed prospective.bThese studies were based in America, the rest in Europe.cCohort studies.dThe outcome variables were not entirely comparable to those of the other studies.eIn these studies, cases and controls were recruited from hospitals.fEstimated risk is for high-affinity serotonin inhibitor antidepressants versus low-activity ones.gPatient-months.