August 24, 2012

One in three, one in six, one in eight?

The Herald says

One in three New Zealanders have been harmed by their own alcohol drinking, a survey shows.

The survey, published in the New Zealand Medical Journal, found 33.8 per cent of current drinkers reported they had been adversely affected in the past year.

This is actually true: there is such a survey, it is published in the NZMJ, and it’s a real survey (the response rate isn’t all one could wish, but it’s not out of line with other major health surveys).  The story goes on to say that the harm was reported more often by men.

The interesting point is that the current issue of NZMJ has two articles about frequency of harm from drinking.  The other one says, also based on real survey data,

The prevalence of self-reported harm from others’ drinking was higher than harm from own drinking (18% vs 12% in the past year) and was higher in women and young people.

And this second survey isn’t pro-alcohol in the slightest — for example, it quotes the proportion of criminal offenders who had been drinking as if it was the proportion of crimes resulting from alcohol.  This is a huge overestimate, precisely because there is too much drinking in NZ: the people who are drunk and arrested in the major cities tend to be just as drunk about three times a week on average (based on Massey Uni. research that we’ve mentioned before).

The timing of these articles is perhaps not a coincidence, but in fact there’s pretty wide consensus about the harms from drinking: the real disagreement is about the costs of various sorts of regulation.


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 »