Between 1997 and 2009, 1,164 biomedical research articles were retracted. In over half the cases, the cause was scientific misconduct ranging from lack of IRB approval to manipulated data. Though worrisome, these articles represent a small portion of all the literature indexed in PubMed.
More concerning is that, according to a new study, many of these articles continue to be cited well after the retraction is posted. Only 6% of the subsequent citations acknowledge that the original article was flawed. The vast majority of citations occur in literature reviews. Because any search of PubMed would turn up a large “Redacted” watermark on the original article, it could be that authors are not conducting fresh searches to find citations for the literature review section.