This is a very plain blog with quotes from and links to articles I found interesting, thought-provoking, or relevant to the times. Linking is neither endorsement nor condemnation. Run by http://willslack.com
06 May, 2017
New Model Predicts Which Mentally Ill Patients Are Unlikely to Be Violent | American Council on Science and Health
Importantly, the model had a negative predictive value of 99.5%. That means if the model predicts that a particular patient is unlikely to commit a violent crime, there is a 99.5% chance that the prognosis is correct. In other words, as the authors write, "of those identified as low risk, 199 of 200 did not in fact offend violently within 1 year."
Unfortunately, the positive predictive value was only 11%. That means if the model predicts a patient is likely to commit a violent crime, there is only an 11% chance that the patient actually will do so. Further research will be needed to improve this aspect of the model.