The effect of a birthday card intervention on 21st birthday celebratory drinking behaviors.

Author:Bass, Ellen J.


To combat hazardous drinking during 21st birthdays, a health-focused birthday card was mailed to 2, 380 college students who later completed an online instrument to assess the campaign's impact. Students reported drinking more during their 21st birthday celebrations than on a typical weekend night. Men consumed more drinks, reached higher estimated blood alcohol concentrations, and tended to experience more negative consequences during 21st birthday celebrations. Students who overestimated their peers' 21st birthday drinking consumed more drinks and experienced more negative consequences than students whose perceptions were accurate or underestimates. Students who received the card before their birthday tended to drink less and experience fewer negative consequences during their birthday compared to those who received the card late.


Hazardous or "binge" drinking is defined by the National Institutes of Health (2004) as blood alcohol concentration (BAC) of 0.08 gram percent or above. Hazardous drinking by college students is associated with adverse academic outcomes including lower grade point averages, suspensions, poor performance on tests and papers, falling behind in schoolwork, and missing classes (Hingson, Zha & Weitzman, 2009; Vickers et al., 2004; Wechsler et al., 2002). Of particular concern is celebratory drinking--holidays, campus or personal events in which a greater proportion of students drink hazardously. Data consistently show increased levels of alcohol consumption during 21st birthday celebrations among college students (Lewis, Neighbors, Lee & Oster-Aaland, 2008; Lewis, Lindgren, Fossos, Neighbors & Oster-Aaland, 2009; Wechsler, Kuo & Lee, 1999) with as many as 90% of 21st birthday celebrants consuming alcohol, 61% attaining BAC levels above the legal driving limit of .08, and 23% reaching dangerously high BAC levels (above 0.25) (Neighbors, Lee, Lewis, Fossos & Waiter, 2009). The practice of consuming 21 drinks during a 21st birthday is a serious problem for those who attempt it and several students have died as a result (Hembroff, Atkin, Martell, McCue & Greenamyer, 2007).

Studies document that students overestimate how much their peers drink. These misperceptions can be associated with higher rates of hazardous alcohol use (Berkowitz 1997; Guha, Bass & Bruce, 2007; Kypri & Langley 2003; Perkins 2002; Perkins & Wechsler 1996; Sher, Bartholow & Nanda, 2001; White et al., 2008). Changing the perception of normative behavior to more accurately mirror true norms has been shown to be an effective strategy for preventing alcohol abuse among college students (Haines 1996; Perkins, Linkenbach, Lewis & Neighbors, 2010; Turner, Perkins & Bauerle, 2008).

The purpose of this study is to characterize the nature of student 21st birthday drinking, compare drinking during 21st birthday celebrations to typical drinking patterns, assess students' perceptions of peers' 21st birthday drinking patterns and evaluate the effectiveness of a campus-specific 21st birthday card campaign.



The Institutional Review Board approved this study at a suburban public university in the southeast. At the university, approximately 30 percent of the undergraduate student population is a member of a fraternal organization. All undergraduate students who turned 21-years-old during a single academic year (n = 2,380) were mailed a health-focused birthday card one to two weeks before their birthday. The card featured a cover photo of a central campus image. The inside of the card included the campus president's signature with the message "Wishing you a healthy and happy birthday!" as well as the message "Happy 21st birthday! We encourage you to celebrate responsibly." with the endorsement of 40 student organizations. Each card included a coupon for a free appetizer or dessert at a local restaurant and a wallet-sized card containing BAC charts, effects of different BAC levels, alcohol poisoning information, and emergency numbers.

A 21-question online, anonymous survey was administered in the month following a student's 21st birthday to measure birthday drinking and related behaviors, evaluate the intervention's effects, and collect data for future social norms-based interventions. Two email reminders were sent to each student and those who completed the survey were entered into a monthly drawing for a $50 gift card at the campus bookstore.


Demographic questions included sex and weight. BAC can be estimated (eBAC) using a formula that uses data on sex, weight, number of drinks and hours spent drinking (Widmark, 1932, 1981). Alcohol measures included questions about typical drinking, number and type of drinks consumed during the 21st birthday celebration, duration of drinking, negative consequences experienced due to drinking and perceptions of others' birthday drinking levels. A sorting question assessed when students received the card. Choices included "before or on the day I celebrated my birthday," "after the day I celebrated my birthday," "I did not receive a card" or "unsure." Students who received the card on time or late were asked dichotomous response questions (yes, no) regarding their perception of the card's appeal and utility.


From the initial sample of 2,380 students, 1,057 responses (44.4%) were collected. Ninety-nine responses were removed due to incomplete surveys or inconsistent responses to questions addressing drinking behaviors (e.g., reporting alcohol consumption over "0" hours). Of the remaining 958 responses, 147 people indicated they did not drink during their 21st birthday celebrations. The remaining 811 responses (521 female, 290 male) were used to analyze 21st birthday drinking patterns.

To examine student perceptions of others' drinking behaviors, two responses were removed as outliers leaving 809 responses (520 female, 289 male). For analyses related to negative consequences, 130 responses were removed due to incomplete or inconsistent responses leaving 679 responses (446 female, 233 male).

Sixty respondents indicated they were "unsure" if they had received a card. These responses were removed, leaving 619 responses (409 female, 210 male) for the analysis of campaign effectiveness. Those students who reported not receiving the card or receiving it after their...

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