Ecological study [Ref: Park, 21/e p59 (19/e, p58) www.ucel.ac.uk.rlos/specs/rlo_observational_study.doc; Repeat Nov 10 & Nov 06 This is an example of ecological study. An ecological study is a type of Observational study where information is collected on a group (or population) rather than on individual members and then analyzed. Here the association between a summary measure of sale of antiarrythmic drugs (risk factor) and summary measure of deaths due to asthma (outcome) is studied. For detailed explanation see Nov10