PUBHLTH 1 Lecture Notes - Lecture 43: Hormone Replacement Therapy, Bran, Pancreatic Cancer
Document Summary
Lecture: problems and limits of epidemiology problems with studying humans. Problems and limits of epidemiology problems with studying humans. Subjects may not follow prescribed behavior throughout study period. Sometimes hard to isolate which of many factors are responsible for health differences. Control group may not be truly comparable also errors in reporting or recall. For all studies, must worry about differential dropouts. News reports (oat bran prevent cancer, to make no difference) Bias selection bias ( heart disease patient, control digestive problems, dietary fat) Results of cohort study were confounded by associated factors that made women taking. Hrt healthier, even without the therapy ethical issues. Tuskegee syphilis study (to observe people who didn"t receive therapy) Possibility of conflict of interest by medical providers who stand to profit. Drug companies are required to conduct randomized controlled trials on any new drug before it can be approved. Harmful side effects have frequently become obvious after drugs were approved.
