Utility of collateral information in assessing substance use among psychiatric outpatients

Purpose. This study addressed the utility of collateral informants for vali dating self-reported substance use by psychiatric outpatients. Methods. Par ticipants were 92 and women with severe and persistent Axis I disorders, at tending outpatient programs ata public psychiatric facility. As part of a s ubstance use assessment, each participant identified a collateral who would provide information about the participant's substance use in the last mont h. The collaterals consisted of family (35%), peers (23%), and others (40%) who were primarily mental health staff. Results. Comparisons of participan t and collateral reports showed high percent agreement with significant but modest measures of association. The likelihood that collateral reports wil l have information value (i.e., corroborate or exceed self-reports) was gre ater when the topic is illicit drug use and the frequency of contact is onc e a week or more. In this sample, siblings were more likely to be uninforma tive than other types of collaterals in the information value of their corr oborative reports. Overall, the collateral reports rarely provided more inf ormation than was provided by the participants themselves. Implications. Th is pattern is consistent with the pattern observed in non-psychiatric sampl es and supports the accuracy of self-reported substance use by psychiatric outpatients.