Impact of Computer-Mediated Versus Face-to-Face Motivational-Type Interviews on Participants' Language and Subsequent Cannabis Use: Randomized Controlled Trial.

backgroundMotivational interviewing (MI) is frequently used to facilitate behavior change. The use of change talk during motivational interviews can predict subsequent behavior change. However, no studies have compared the information obtained from traditional face-to-face motivational interviews and computer-mediated motivational interviews or resulted in the same amount of behavior change.

objectiveThis study aimed to investigate if face-to-face motivational-type interviews (MTIs) and computer-mediated MTIs elicit the same amount of "change talk" and behavior change when young adults discuss their ambivalence about using marijuana.

methodsA total of 150 users, including frequent marijuana users, occasional marijuana users, and non-marijuana users, participated in the study. All participants reported being at least moderately ambivalent about their current level of marijuana use. Participants were randomly assigned to complete a brief MTI using either the standard face-to-face format or a computer-mediated format. Amrhein's manual for assessing the presence of "change talk" and "sustain talk" was used to code the language produced by respondents in each interview format. A reduction in marijuana use was assessed at a 2-month follow-up.

resultsThe word count was significantly higher in face-to-face MTIs compared with computer-mediated MTIs (P<.001). After controlling for verbosity, face-to-face MTIs, and computer-mediated MTIs did not differ statistically in the overall amount of change talk (P=.47) and sustain talk (P=.05). Face-to-face MTIs elicited significantly more reasons for reducing future marijuana use (ie, change talk; P=.02) and readiness toward not using marijuana (ie, change talk; P=.009), even after controlling for verbosity. However, these differences were not statistically significant after using a conservative Bonferroni correction (P<.004). After controlling for marijuana use at Time 1, the relationship between the strength of commitment language at Time 1 and marijuana use at Time 2 was not statistically significant (semipartial correlation r=0.03, P=.57). The association between Time 1 change talk and Time 2 marijuana use depended on the type of motivational interview that participants experienced: face-to-face MTI versus computer-mediated MTI (B=0.45, P=.01). A negative binomial regression with a log link function was used to probe this relationship after controlling for 2 covariates: gender and Time 1 (baseline assessment) marijuana use. Among participants in the face-to-face MTI condition, Time 2 (follow-up) marijuana use decreased as the strength of Time 1 change talk increased, although this finding was not significant (B=-0.21, P=.08). However, among participants in the computer-mediated MTI condition, Time 2 marijuana use was not significantly related to the strength of Time 1 change talk (B=0.13, P=.16).

conclusionsComputer-mediated MTIs and face-to-face MTIs elicit both change talk and sustain talk, which suggests that motivational interviews could potentially be adapted for delivery via text-based computer platforms. However, further research is needed to enhance the predictive validity of the type of language obtained via computer-delivered MI.

trial registrationClinicalTrials.gov NCT06945471; https://clinicaltrials.gov/study/NCT06945471.