Clustering of Unhealthy Behaviors in the Aerobics Center Longitudinal Study

Clustering of unhealthy behaviors has been reported in previous studies; however the link with all-cause mortality and differences
between those with and without chronic disease requires further investigation.

To observe the clustering effects of unhealthy diet, fitness, smoking, and excessive alcohol consumption in adults with and
without chronic disease and to assess all-cause mortality risk according to the clustering of unhealthy behaviors.

Participants were 13,621 adults (aged 20–84) from the Aerobics Center Longitudinal Study. Four health behaviors were observed
(diet, fitness, smoking, and drinking). Baseline characteristics of the study population and bivariate relations between pairs
of the health behaviors were evaluated separately for those with and without chronic disease using cross-tabulation and a
chi-square test. The odds of partaking in unhealthy behaviors were also calculated. Latent class analysis (LCA) was used to
assess clustering. Cox regression was used to assess the relationship between the behaviors and mortality.

The four health behaviors were related to each other. LCA results suggested that two classes existed. Participants in class
1 had a higher probability of partaking in each of the four unhealthy behaviors than participants in class 2. No differences
in health behavior clustering were found between participants with and without chronic disease. Mortality risk increased relative
to the number of unhealthy behaviors participants engaged in.

Unhealthy behaviors cluster together irrespective of chronic disease status. Such findings suggest that multi-behavioral intervention
strategies can be similar in those with and without chronic disease.