Web-based self-help with and without chat counseling to reduce cocaine use in cocaine misusers: results of a three-arm randomized controlled trial (Preprint)
Authors: Schaub Michael P. , Paz Castro Raquel , Wenger Andreas , Baumgartner Christian , Stark Lars , Ebert David D. , Quednow Boris B. , Haug Severin 
Published: April 2018

BACKGROUND

In recent years, cocaine use has increased in many countries and only a minority utilize treatment. To date, no pharmacological therapy has been proven effective and cognitive behavioral therapy (CBT) is seen as first-choice treatment. However, a web-based intervention might be an alternative treatment option.

OBJECTIVE

To test the efficacy of a Web-based self-help intervention, with and without chat counseling, grounded in CBT—called Snow Control 2.0—at reducing cocaine use in cocaine misusers and those with early cocaine dependence not in treatment for a substance use disorder (SUD).

METHODS

Subjects were randomly assigned to one of three unblinded study arms: (1) a self-help intervention with chat support; (2) self-help intervention program without chat support; or (3), a waiting-list control group. Follow-up assessments were conducted six weeks and six months following a baseline assessment. The fully-automated self-help program consisted of eight modules based on motivational interviewing, self-control practices and CBT. The primary outcome was the quantity of cocaine use per week. Secondary outcomes included frequency of cocaine and other substance use, severity of cocaine dependence, mental health symptoms, working alliance, client satisfaction, intervention participation, and program retention.

RESULTS

In total, 416 users tried to register online for the web-based trial, of whom 311 completed the baseline assessment. The numbers in treatment arms 1 through 3 were n=114, n=108 and n=89, respectively. Participants were predominantly male (73%), and averaged 33 years old (SD = 7.6). Despite considerable efforts, only 47 of 311 (15.1%) subjects completed the 6-month follow-up. No significant difference in the primary outcome was observed between the three study arms, by either intention-to-treat (ITT) or complete case (CCA) analysis. Several differences in secondary outcomes were observed by CCA, but not confirmed by ITT analysis. Group 1 subjects reported a greater reduction in cocaine use frequency (CCA: Cohens’ d [d]=-0.74, confidence interval [CI]: -1.43; 0.00, P=0.046) than controls at six months of follow-up. At six weeks follow-up, days of risky alcohol were significantly more reduced in treatment arms 1 (CCA: d=-1.06, CI: -1.81; -0.24, P = 0.005) and 2 (CCA: d=-1.09, CI: -1.86;-0.26, P=0.02) than in controls. Also at six weeks, non-risky alcohol use was significantly more reduced in arm 2 than both arm 1 participants (CCA: d=0.66, CI: 0.00;1.30, P=0.047) and controls (CCA: d=-0.85, CI: -1.58;-0.08, P=0.01). Participants in arm 1 completed a mean of 3.43 (SD=2.80) modules, which was significantly more (t112= -5.756, P <0.00) than the mean 2.71 (SD=2.44) modules completed in arm 2.

CONCLUSIONS

This study failed to demonstrate the efficacy of a chat-guided self-help internet intervention in cocaine misusers recruited from the general population and not otherwise in treatment because of the high dropout rate. Nevertheless, particularly-motivated cocaine misusers might profit from such an intervention.

CLINICALTRIAL

Current Controlled Trials, ISRCTN12205466, http://www.isrctn.com/ISRCTN12205466