Reflective studies, i.e. studies that reflect on or discuss about alcohol prevention and/or the usability of social marketing, and that do not discuss an own data set, were excluded from this review. Reviews on alcohol and/or social marketing were excluded because we searched for original papers. No restrictions on language, publication date, or publication status were imposed. Moreover, there were no limitations on the type of intervention, age of participants, or the study design. The main outcome measure for this review study was a change in the occurrence of protective behaviour towards alcohol, i.e. a change in drunk driving or in high-risk drinking.
To establish that the 274 eligible studies met the inclusion criteria for this review, all abstracts were reviewed independently by at least two researchers. The 25 most recent studies found in Pubmed were reviewed by three researchers. After reading the abstracts, 250 studies were immediately rejected because they clearly did not meet the inclusion criteria. Two studies were included by both researchers (with no doubts) based on reading the abstract. After reading the abstracts of 22 studies, either one or both of the researchers had some doubts about inclusion; therefore, two researchers independently judged the full texts. Of these 22 studies, four met the inclusion criteria and were included, whereas 18 did not meet the inclusion criteria and were finally rejected (see Figure 1).