Thread: Is this an OBSERVATIONAL STUDY or ANECDOTAL EVIDENCE?

In the July issue of Archives of Neurology, researchers reported studying the smoking habits of 12000 people (3000 with Parkinson's disease and 9000 healthy people). They found that those who had smoked the most (the equivalent of a pack a day for 60 years) had the lowest risk of getting Parkinson's disease.Was this anecdotal evidence, an observational study or an experiment?


First post

Also could you give me some tips on how to determine between observational and anecdotal because I can never get these questions right.

This would be an observational study. In an experiment, the researchers set up groups (like a control and a treatment group) and then impose the condition (ie smoking a pack a day vs. no smoking) on the groups. No experiment could ethically be set up in which some of the participants were ASKED to smoke a pack a day, so this is an observational study based on looking at people who were already doing so by their own choice.