Predictors of changes in physical activity in a prospective cohort study of the Danish adult population.
OBJECTIVE
To investigate predictors of changes in physical activity, in a prospective population-based study.


METHODS
Data were from the Danish Health Interview Surveys in 1994 and 2000, and included persons between 16 and 64 years of age who answered the questions on physical activity and various covariates in 1994, and who were re-interviewed in 2000. In total 2,957 subjects participated (62% of the original sample). Data were analysed using logistic regression.


RESULTS
Predictors of physical inactivity were, for men and women respectively, heavy smoking (odds ratio (OR) 2.07, 95% confidence interval (CI) 1.24-3.48, and OR 2.23, 95% CI 1.34-3.71), poor self-rated health (OR 2.11, 95% CI 1.25-3.58, and OR 1.75, 95% CI 1.10-2.80), and believing that one's own effort has no effect on health (OR 1.86, 95% CI 1.20-2.88, and OR 1.63, 95% CI 1.00-2.65). For men, further predictors for physical inactivity were obesity as compared to normal weight (OR 2.10, 95% CI 1.11-3.98), and being unmarried as compared to being married (OR 2.22, 95% CI 1.40-3.51). The only predictor for becoming physically active among initially sedentary respondents was meeting often with family (p=0.011).


CONCLUSIONS
Our results show a number of strong predictors for physical inactivity. Variables of an unhealthy lifestyle tend to cluster in some individuals, and physical inactivity interventions may therefore be more successful if they also address smoking, self-belief, and obesity. Interventions tailored to raise inactive people's level of activity should focus on social support from the family.
Zimmermann
Esther
E
National Institute of Public Health, Copenhagen, Denmark.
Ekholm
Ola
O
Grønbaek
Morten
M
Curtis
Tine
T
D000293:Adolescent; D000328:Adult; D001294:Attitude to Health; D015331:Cohort Studies; D003718:Denmark; D015444:Exercise / Q000502:physiology; D005260:Female; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects; D012944:Social Support; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires