March 26, 2012

Student drinking

A story in Stuff about student drinking at Otago illustrates an important problem with surveys.  According to the story, the students drank on average two nights a week, and consumed 7.2 drinks per night of drinking.  That gives an average of about two drinks per day, which is about the same as average for the whole country based on total alcohol sales.

I don’t know about you, but I find this a little hard to believe. The newspapers should find it even harder to believe, since it contradicts their usual line about Otago students.

My guess is that Otago students do drink a bit more than the average Kiwi, but that asking people to report their drinking leads to underreporting compared to looking at total sales.  There could be several reasons.  One is that people might not want to admit how much they drink, another is that there may be difficulties in converting actual glass sizes into standard doses, and a third is that people’s “average week” is usually different from their actual week.  Perhaps you `usually’ drink less, but this week was Sam’s birthday and you drank more.  And last week was the keg party. And before that was the start of semester. And so on.

That’s not the point of the story, though.  The point is that new research finds heavy drinking can make you feel unwell and have difficulty concentrating even the next day;  the effects seem to hang over and affect your daily activities. Perhaps someone could come up with a catchy name for this phenomenon…

avatar

Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments