Our study found that current (i.e., past 30 days) drinking rates and heavy drinking behavior among drinkers declined significantly during a period of increased restrictions on alcohol at Massachusetts public colleges and universities. While the great majority of students continued to report some drinking, study results suggest that heavy
drinking may have declined, particularly among underage students and on-campus residents, for whom the school's alcohol policy may have greater impact. This apparent decline occurred despite an overall higher
percentage in 2001 of students in our sample reporting heavy drinking during their last year in high school, a known risk factor for heavy drinking in college [16
]. During the same time period, the national CAS found no significant change in the heavy drinking rate for public colleges and universities nationally (N = 61 schools excluding MA, heavy drinking rate 1999 48.3% vs. 2001 47.7%, p = NS (unpublished data)). However, there was a trend towards a decline (1999 52.8% vs. 2001 48.2%, p = .02) for students attending public colleges in the Northeast (Nelson T.F., personal communication). Therefore, the decline in MA may in part reflect, and have contributed to, this regional trend and our study findings may be confounded by other contextual factors that may have influenced student drinking patterns region-wide.
We were able to examine data from one school included in both our sample and the CAS sample prior to (1993, 1997) and after (2005) our study period, allowing us to look at trends for that school both leading up to and extending beyond our study period. This school's heavy drinking rates (weighted) steadily increased through 1999 (1993 58%, 1997 63%, 1999 71%), declined in 2001 (55%), and increased again by 2005 (67%) (unpublished data). The brief interruption of the upward trend immediately following the MA Board of Higher Education policy change could be, in part, due to the stricter alcohol policy, as well as to the increased attention to underage drinking generated by the two student deaths. However, the decline between 1999 and 2001 was short-lived at this school, and possibly statewide. Over time, memories can fade and enforcement may wane, leading to drinking behaviors returning to previous or even higher than previous levels.
Heavy drinking appeared to be less common over time as a usual drinking pattern among female students who drink, while there was no such change for men. Previous studies have found gender differences in both the likelihood of engaging in heavy episodic drinking, as well as the factors that increase the risk of heavy drinking in college [16
]. Men tend to engage in heavy drinking more frequently than women, and to drink heavily more often than originally intended [24
]. High-risk drinking among men may be more normative and entrenched, and therefore more difficult to reduce, requiring intervention strategies different from those that are effective for women.
College is a time of significantly increased drinking prevalence compared to the rates found among college-bound 12th
graders and non-college-attending young adults [1
], indicating that many students take up heavy drinking when they arrive at college. We found declining trends between 1999 and 2001 in the rate of heavy drinking uptake
among on-campus and underage students, groups that are more likely to feel the impact of stricter school alcohol policy enforcement and to be affected by sanctions.
We found no evidence of a rise in marijuana use as a possible unintended consequence of stricter alcohol policy enforcement. Trend data from the CAS and Monitoring the Future studies which showed a rise in marijuana use among college students between 1993 and 1999, a time of increased restrictions on alcohol use, caused concern about students substituting marijuana and other drugs for alcohol [22
]. However, a report by Williams et al. found that government and campus anti-drinking policies (e.g., banning alcohol on campus, "happy hour" restrictions) were associated with lower rates of both
alcohol and marijuana use, suggesting that demand for alcohol and marijuana may be complementary rather than substitutive [27
]. While marijuana use rates changed little during our 2-year study period, we are not able to say whether use of other illicit drugs changed since analysis of other drug use trends was beyond the purview of this study.
Another possible unintended consequence of a stricter college alcohol policy is that students may go off campus to drink. We found a marginally significant increase in the prevalence of past-30-days DWI/RWID behavior among on-campus but not off-campus residents. This finding may indicate that students were more likely to go off campus to drink in response to the greater restrictions. However, we did not measure community characteristics and changes in local policies which could have contributed to this trend [28
], and therefore cannot determine causality
In examining whether stricter policy enforcement was associated with changes in school drinking rates, we found that deans' perceptions of enforcement strength in 1999 were associated with greater subsequent
declines in heavy drinking rates during the study follow-up period. In addition, schools with consistently
high dean's enforcement scores appeared to have greater declines in past-2-weeks HED compared to schools with lower scores over time. In our previous cross-sectional study of 1999 data, however, we found that deans' enforcement scores had weak to moderate positive
correlations with concurrent
student drinking rates. In contrast, security chiefs' reports were strongly, and negatively
, correlated with concurrent
drinking rates [6
] but showed lower associations with drinking rate change
over time (i.e., higher enforcement scores were more associated with increases in drinking rates).
We hypothesize that the difference in our findings between the two studies may be due to the different perspectives that deans and campus security chiefs have on policy enforcement. Security chiefs are likely more knowledgeable about day-to-day enforcement activities and events, particularly those happening on evenings and weekends when students are more likely to drink. Their stricter enforcement may have a more immediate deterrent effect. On the other hand, deans may be more likely to base their enforcement perceptions on the number of students caught for violations, because they are usually charged with meting out disciplinary sanctions. In schools with more widespread drinking, deans may have more students to discipline, therefore resulting in a positive correlation between enforcement and drinking rates in a cross-sectional study. On the other hand, a more aggressive enforcement stance by deans may over time bring about changes in student perceptions and behavior, with fewer students initiating heavy drinking in college or engaging in heavy drinking as a usual behavior.
Our previous study [6
] found that students' perceptions of enforcement were positively correlated with their own drinking behavior (i.e., students who drank were more likely to report strong enforcement compared to non-drinkers). In the follow-up study, students' perceptions of enforcement had little or no association with changes in drinking rates over time. Given the biased perspective that may result from students' susceptibility to getting sanctioned for drinking, students may not be the best informants about alcohol policy enforcement.
This longitudinal study represents an important extension of our previous cross-sectional study, allowing us to investigate the prospective relationship between alcohol policy enforcement levels and changes in rates of student drinking and associated behaviors across a statewide system of schools with a uniform alcohol policy. Our study adds to the growing body of work that suggests that environmental strategies addressing underage alcohol use can help to lower high-risk college drinking and associated behaviors [29
]. In particular, multi-strategy efforts, such as that promulgated by the new MBHE policy, which combine multiple environmental strategies with individual student-focused interventions, were associated with reduced underage drinking, driving after drinking, and secondhand effects of student drinking [29
]. For example, in their evaluation of the Matter of Degree program, a multi-strategy environmental initiative to reduce college drinking and related harms, Weitzmann and colleagues found that communities implementing a high number of interventions and programs to address alcohol availability, legal sanctioning, parent and peer influences, etc. significantly reduced their college student heavy drinking rates, while those with low implementation did not [34
]. In addition, Toomey and colleagues cautiously suggest, based on their recent review of the extant research on the effects of environmental policies on college drinking, that a multi-pronged strategy involving campus-community collaboration, more alcohol-control policies, and stronger policy implementation and enforcement, may be effective; however, they point out that most studies had methodological issues such as a cross-sectional observational design and lack of multiple sites for comparison and further work is needed to more rigorously assess cause and effect [29
This study had several strengths such as a longitudinal follow-up; inclusion of the assessment of multiple perspectives of alcohol policy enforcement; the use of multi-item enforcement measures that examined a range of enforcement activities, experiences, and venues; and the evaluation of alcohol use and related outcomes, as well as potential unintended consequences of a stricter alcohol policy (i.e., increased driving while intoxicated/riding with an intoxicated driver, and marijuana use). Our study also had a number of limitations. The number of schools was small, limiting the power of school-level analyses; we examined only two points in time; and we relied on self-reported rather than observational measures. In addition, the student survey response rates were generally low (range 38%-54%), raising concerns about potential selection bias and inaccurate estimates of student drinking rates. In examining whether heavy drinking prevalence estimates were associated with response rates, we found low correlations in both baseline and follow-up years. We also used direct standardization of the two years' samples to control for demographic differences in our comparisons of the two time points. Of greater concern is that student self-selection into particular schools because
of the drinking policy may confound the association between policy enforcement and student drinking rates. If a stricter alcohol policy in the MA public colleges caused more drinking students to choose alternatives (e.g., private schools) over the public colleges, thus resulting in lower drinking rates in 2001, we would expect to find lower rates of high school HED among students in 2001 compared to 1999. Instead, we found the opposite, with more
students in the 2001 sample reporting HED in high school than in 1999. Finally, we did not assess other influential environmental or individual factors that may confound the relationship between enforcement measures and student drinking trends (e.g. social marketing campaigns, student education and counseling, provision of alcohol-free alternative activities, community and state policies and regulations, alcohol pricing and promotion, and ease of access) [21
]. We are also unable to identify the factors underlying the differences in administrator perceptions of policy enforcement such as different response biases that deans and campus security chiefs may have had. Because of these limitations, we advise caution in inferring a cause-effect relationship from our study results.
Future studies examining college alcohol policy enforcement should include many more schools, survey other key informants such as residence hall assistants and resident directors, include direct observation of campus enforcement practices (e.g., how often student ID's are checked at campus events, how frequently student bags are searched when entering dorms, etc.), and chronicle other on-campus and community-wide efforts to reduce student drinking.