Psychotherapy process research examines the content of treatment sessions and their association with outcomes in an attempt to better understand the interactions between therapists and clients, and to elucidate mechanisms of behavior change. A similar approach is possible in technology-delivered interventions, which have an interaction process that is always perfectly preserved and rigorously definable. The present study sought to examine the process of participants' interactions with a computer-delivered brief intervention for drug use, from a study comparing computer- and therapist-delivered brief interventions among adults at two primary health care centers in New Mexico. Specifically, we sought to describe the pattern of participants' (N =178) choices and reactions throughout the computer-delivered brief intervention, and to examine associations between that process and intervention response at 3-month follow-up. Participants were most likely to choose marijuana as the first substance they wished to discuss (n =114, 64.0%). Most participants indicated that they had not experienced any problems as a result of their drug use (n =108, 60.7%), but nearly a third of these (n =32, 29.6%) nevertheless indicated a desire to stop or reduce its use; participants who did report negative consequences were most likely to endorse financial or relationship concerns. However, participant ratings of the importance of change or of the helpfulness of personalized normed feedback were unrelated to changes in substance use frequency. Design of future e-interventions should consider emphasizing possible benefits of quitting rather than the negative consequences of drug use, and—when addressing consequences—should consider focusing on the impacts of substance use on relationship and financial aspects. These findings are an early but important step toward using process evaluation to optimize e-intervention content. 
Process evaluation of a technology-delivered screening and brief intervention for substance use in primary care