Erratum to: Evaluating the efficacy of a web-based self-help intervention with and without chat counseling in reducing the cocaine use of problematic cocaine users: the study protocol of a pragmatic three-arm randomized controlled trial

Affiliations

• ¹ Swiss Research Institute for Public Health and Addiction at the University of Zurich, Konradstrasse 32, Zurich, Switzerland. [email protected].
• ² Swiss Research Institute for Public Health and Addiction at the University of Zurich, Konradstrasse 32, Zurich, Switzerland.
• ³ Arud, Centres for Addiction Medicine, Konradstrasse 32, Zurich, 8005, Switzerland.
• ⁴ Department of Psychiatry, Psychotherapy and Psychosomatics, Clinical and Experimental Pharmacopsychology, Psychiatric Hospital of the University of Zurich, Lenggstrasse 31, Zürich, 8032, Switzerland.