Comparisons of mean personality scores in the general population and the restaurant employees were made by Student’s
f-tests. Logistic regression analyses were performed with heavy/not heavy drinking as the dependent variable. Associations
with heavy drinking were measured by the odds ratio, which approximates the relative risk of being a heavy drinker. The
personality scores were categorized into three equally large groups to achieve a presentation not dependent on a specific
relationship. The effects of neuroticism and extraversion were controlled for by gender, age-group, household type and
occupation. The separate effect of each factor was tested by a log-likelihood ratio test, and 95% confidence intervals were
given for each of the non-reference categories of the factors. No significant differences between men and women were found,
and results were therefore presented for both genders combined. The level of significance was 5%. and two-tailed tests were
used. Factor analysis with principal component estimation and varimax rotation confirmed the dimensionality of the
abbreviated questionnaire in the present sample. Statistical analyses were performed on BMDP (Dixon, 1990).