Multiple Forensic Interviews During Investigations of Child Sexual Abuse: A Cost-Effectiveness Analysis.

In cases of suspected child sexual abuse (CSA) some professionals routinely recommend multiple interviews by the same interviewer because any additional details provided might improve decision-making and increase perpetrator convictions. We analyzed alternative policies about child interviewing to estimate the probability that a policy of all children receiving multiple interviews will increase criminal convictions and better protect children. Using decision analysis, we prepared a decision tree reflecting the structure through which a case of possible CSA passes through the health care, welfare, and legal systems with an estimated probability of conviction of the offender. We reviewed the CSA disclosure, criminal justice, and child welfare literature to obtain estimates for the median and range of rates for the steps of disclosure, substantiation, criminal charges, and conviction. Using the R statistical package, our decision analysis model was populated using literature-based estimates. Once the model was populated, we simulated the experiences of 1,000 cases at 250 sets of plausible parameter values representing different hypothetical communities. Multiple interviews increase the likelihood that an offender will be convicted by 6.1% in the average community. Simulations indicate that a policy in which all children seen for a CSA medical evaluation receive multiple interviews would cost an additional $100,000 for each additional conviction. We estimate that approximately 17 additional children would need to be interviewed on more than one occasion to yield one additional conviction. A policy of multiple interviews has implications for the children, for the costs of care, for protecting other children, and for the risk of false prosecution.