RESULTS
Table 1 shows the baseline characteristics of the
population for men and women. Nearly half of the
population had inadequate physical activity, 36% of
the population smoked at least 1 cigarette per month,
and about 70% of the population had an inadequate
intake of fruit and vegetables, according to the Dutch
guidelines for healthy nutrition. Except for excessive
alcohol consumption, there were no great differences
between men and women in lifestyle risk factors. In
Table 2 the observed and expected prevalence of unhealthy lifestyle factors in the population is depicted.
About 10% of the population did not have any lifestyle risk factor, whereas approximately 20% had three or
four lifestyle risk factors. In both men and women the
proportion of men and women having four risk factors
was higher than can be expected on the basis of the
individual frequencies (O/E ratio in men: 1.6, women:
1.7). This indicates a 60 to 70% increase in subjects
with four risk factors over that which would be expected if the risk factors were independent. The number of risk factors was higher among subjects with a
low education, those who were unemployed, those living without a partner (men only), those who had lower
self-rated health, and those who reported that their
health was worse than 1 year ago (Table 3). The prevalence of two lifestyle risk factors simultaneously and
the odds ratio per category of age, education, self-rated
health, and health relative to 1 year ago are summarized in Table 4. All risk factors were significantly
associated with each other, except for excessive alcohol
consumption and low physical activity (“overall” prevalence odds ratio (adjusted for age, gender, and education) was 1.04). The combination of smoking and alcohol consumption showed the strongest clustering
(POR 2.38, 95% CI 2.18–2.61). The relationship
between the several risk factors was similar in all age
categories, except for the relation between smoking
and alcohol consumption, which was stronger in the
age category 20–29, and the relation between smoking
and low fruit/vegetable consumption, which was stronger in the highest age category. We did not find differential clustering with respect to education. We did,
however, observe a somewhat stronger relation between smoking and alcohol consumption and between
smoking and low physical activity in subjects who
rated their health excellent or very good. The relation
between excessive alcohol consumption and low intake
of fruits/vegetables was, on the other hand, stronger in
those who rated their health as moderate or bad. Finally, the relation between various risk factors was
generally stronger in subjects who had perceived a
deterioration in health in the past year.