Effects of 21st birthday brief interventions on college student celebratory drinking: A systematic review and meta-analysis

Introduction: College students' 21st birthday celebrations often involve consumption of extreme amounts of alcohol as well as alcohol-related risks. This systematic review aims to determine whether birthday-focused, individually-targeted, no-contact (email or letter-based) brief alcohol interventions (BAIs) reduce college students' 21st birthday celebratory drinking.

Methods: A systematic search identified 9 randomized evaluations with 10 interventions to reduce 21st birthday drinking. Quantity of alcohol consumed and estimated blood alcohol concentration (BAC) were measured. Random-effects meta-analysis was used to summarize the effects of the interventions.

Results: There was no evidence that birthday-focused BAIs reduce quantities of alcohol consumed during birthday celebrations (g = 0.05, 95% CI [-0.03 to 0.13]). The interventions were associated with significant reductions in estimated BAC levels (g = 0.20, 95% CI [0.07 to 0.33]), but this effect was small in absolute terms. The quality of this body of evidence was very low, as evaluated using the GRADE approach. In particular, it was limited by substantial participant attrition post-randomization due to included studies' recruitment and randomization procedures.

Conclusions: There is no evidence that birthday-focused, individually-targeted BAIs reduce the quantity of alcohol consumed by students during 21st birthday celebrations, although these interventions may yield small beneficial effects on estimated BAC. Many methodological concerns were identified in included studies. This area of research would benefit from theory-based RCTs that are well-designed and executed. Future research should also investigate strategies other than birthday-focused, individually-targeted, brief interventions to curb 21st birthday celebratory drinking.