Editing Selection bias (section)

===Exposure===
* ''Susceptibility bias''
** ''Clinical susceptibility bias'', when one disease predisposes for a second disease, and the treatment for the first disease erroneously appears to predispose to the second disease. For example, [[postmenopausal]] syndrome gives a higher likelihood of also developing [[endometrial cancer]], so estrogens given for the postmenopausal syndrome may receive a higher than actual blame for causing endometrial cancer.<ref name=fenstein>{{cite journal |author1=Feinstein AR |author2=Horwitz RI |title=A critique of the statistical evidence associating estrogens with endometrial cancer |journal=Cancer Res. |volume=38 |issue=11 Pt 2 |pages=4001–5 |date=November 1978 |pmid=698947}}</ref>
** ''Protopathic bias'', when a treatment for the first symptoms of a disease or other outcome appear to cause the outcome. It is a potential bias when there is a lag time from the first symptoms and start of treatment before actual diagnosis.<ref name=fenstein/> It can be mitigated by [[lagging (epidemiology)|lagging]], that is, exclusion of exposures that occurred in a certain time period before diagnosis.<ref>{{cite journal |author1=Tamim H |author2=Monfared AA |author3=LeLorier J |title=Application of lag-time into exposure definitions to control for protopathic bias |journal=Pharmacoepidemiol Drug Saf |volume=16 |issue=3 |pages= 250–8 |date=March 2007 |pmid=17245804 |doi=10.1002/pds.1360|s2cid=25648490 }}</ref>
** ''Indication bias'', a potential mixup between cause and effect when exposure is dependent on indication, e.g. a treatment is given to people in high risk of acquiring a disease, potentially causing a preponderance of treated people among those acquiring the disease. This may cause an erroneous appearance of the treatment being a cause of the disease.<ref>{{cite book |author=Matthew R. Weir |title= Hypertension (Key Diseases) (Acp Key Diseases Series) |publisher=American College of Physicians |location=Philadelphia, Pa |year=2005 |page=159 |isbn=978-1-930513-58-7}}</ref>