As far as I understood, an "autopsy study" means a study where the researchers decide to perform an autopsy to all of patients in their sample. A quick googling

As far as I understood, an "autopsy study" means a study where the researchers decide to perform an autopsy to all of patients in their sample. A quick googling seems to support this meaning, links below. If this is the case, then the results do not contain the bias you are suggesting. http://www.ncbi.nlm.nih.gov/pubmed/10877491 http://www.ncbi.nlm.nih.gov/pubmed/10877491 http://www.ncbi.nlm.nih.gov/pubmed/18288887 http://www.ncbi.nlm.nih.gov/pubmed/18288887 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0033685 http://journals.plos.org/plosone/article?id=10.1371/journal....