Wednesday, September 4, 2013
Risk assessment tools plagued by 'authorship bias,' study finds
"Reported predictive validity higher in studies by an instrument's designers than by independent researchers
The use of actuarial risk assessment instruments to predict violence is becoming more and more central to forensic psychology practice. And clinicians and courts rely on published data to establish that the tools live up to their claims of accurately separating high-risk from low-risk offenders.
But as it turns out, the predictive validity of risk assessment instruments such as the Static-99 and the VRAG depends in part on the researcher's connection to the instrument in question.
Publication bias in pharmaceutical research has been well documented
Published studies authored by tool designers reported predictive validity findings around two times higher than investigations by independent researchers, according to a systematic meta-analysis that included 30,165 participants in 104 samples from 83 independent studies."
Are Forensic Experts Biased by the Side That Retained Them?
How objective are forensic experts when they are retained by one of the opposing sides in an adversarial legal proceeding? Despite long-standing concerns from within the legal system, little is known about whether experts can provide opinions unbiased by the side that retained them. In this experiment, we paid 108 forensic psychologists and psychiatrists to review the same offender case files, but deceived some to believe that they were consulting for the defense and some to believe that they were consulting for the prosecution. Participants scored each offender on two commonly used, well-researched risk-assessment instruments. Those who believed they were working for the prosecution tended to assign higher risk scores to offenders, whereas those who believed they were working for the defense tended to assign lower risk scores to the same offenders; the effect sizes (d) ranged up to 0.85. The results provide strong evidence of an allegiance effect among some forensic experts in adversarial legal proceedings."
Letters: Psychiatry's diagnosis bloat
"Diagnosis bloat is rampant in the medical profession, and it would be
healthy if we took a skeptical view and consider how much of this is
simply one group attempting to increase its market share of struggling
Treatment Outcome and the Risk Principle