University of Iowa officials were quick to endorse the results of a campus student-health survey by the National College Health Association, claiming the data indicated the success of initiatives such as the Alcohol Harm Reduction Plan enacted in 2009.

From the data, it is impossible to definitively discern that any changes in behavior are direct results of UI policies. Correlation does not imply causation. But, despite student skepticism, the survey results do show a positive trend toward more responsible drinking among the students and seem to suggest that the university’s efforts to reduce harmful drinking habits are having a positive effect.

The sampling method limits the accuracy of the survey’s results. The survey used a convenience sample rather than a simple random sample; instead of giving every student an equal chance of being surveyed, the study included 875 students in the University’s Health and Physical Activity Skills classes. Any efforts to ensure that the sample of students in this class was representative of the students as a whole were not indicated in the report.

In addition, many of the survey data are based on student recollections of their drinking behavior. Students may not always report this information accurately, although the survey was anonymous. The self-reporting nature of the survey also gives it more credibility than some other measures of drinking behavior, such as relying on arrest statistics, because the survey relies specifically on each student’s experience rather than interactions with police. Additionally, the conclusions drawn about the decrease were a result of comparisons with previous surveys, all of which used the same self-reporting mechanism.

Still, the sample size was fairly large, and the response rate for the survey was 98 percent. The numbers aren’t perfect, but they may be a useful tool in determining student drinking behaviors.

Some UI officials are using the data to prove the success of the 21-ordinance, a broad assertion that isn’t proven by the data. UI Vice President for Student Life Tom Rocklin told The Daily Iowan that he is confident that the largest decrease in binge drinking occurred from 2010 to 2011, after the ordinance went into effect. Because no data were collected in 2010, however, no evidence can be cited to prove or disprove this claim.

The evidence does suggest that the university’s alcohol-safety initiatives are making progress. Kelly Bender, the UI coordinator of Campus and Community Alcohol Harm Reduction Initiatives, emphasized the effectiveness of using a wide range of initiatives coordinated between the campus and the community.

“Our belief is that there have been a variety of strategies implemented that are successful, and the 21-ordinance is part of those strategies,” Bender told the DI Editorial Board last week.

The opposition to the ordinance also has little support in the data. There is no evidence in the survey to suggest that the 21-ordinance has led to an increase in harmful drinking behavior, as some feared. Matt Pfaltzgraf, the former leader of Yes to Entertaining Students Safely, was skeptical about the effect of the ordinance. He told the DI that students are adjusting to the university’s anti-binge-drinking efforts and “shifting their behavior.” He explained that students have moved into neighborhoods to drink instead of drinking downtown.

One statistic that could show a change in behavior is the number of disorderly house citations, which has increased since the ordinance went into effect. But disorderly house citations are not a reliable barometer of drinking behavior; the data are unclear on whether the increased number of citations is due to more partying or a result of the Iowa City police’s ramped-up enforcement efforts. The national survey measures drinking habits, not drinking locations — no matter where students are drinking, the data from the survey indicate that they are drinking less.

When the ordinance went into effect, some were concerned about a possible increase in drunk driving as students drove to houses instead of taking buses or taxis downtown. Among survey respondents, the opposite is true — 24 percent fewer students reported operating a vehicle while intoxicated than in 2009, a substantial decrease and a very encouraging trend.

Survey results also indicated a decrease in the number of incidents of violence experienced by survey respondents. Twenty-nine percent fewer students reported injuring themselves as a result of alcohol, and 36 percent fewer reported getting into a physical fight.

These statistics bolster the UI’s claims that its alcohol-harm-reduction initiatives are working. However one feels about the university spending money to cut back on student drinking, a decrease in the negative consequences of drinking is laudable. At the same time, it’s difficult to tie the progress to any specific program.

The flaws in sampling and the lack of data from 2010 mean the results are far from a ringing endorsement of the administration’s policies or the 21-ordinance, with no data directly linking the changes in behavior to the anti-binge-drinking measures. Specifically, no questions in the survey attempted to forge a connection between specific initiatives and a reduction in alcohol use.

Still, the data do seem to indicate an encouraging trend among students, who appear to be consuming alcohol more responsibly and less dangerously. No matter where the credit is due, increased student safety is always welcome.