OBJECTIVE:

To provide the simultaneous 7-year estimates of incremental costs of smoking and obesity among employees and dependents in a large health care system.

METHODS:

We used a retrospective cohort aged 18 years or older with continuous enrollment during the study period. Longitudinal multivariate cost analyses were performed using generalized estimating equations with demographic adjustments.

RESULTS:

The annual incremental mean costs of smoking by age group ranged from $1274 to $1401. The incremental costs of morbid obesity II by age group ranged from $5467 to $5530. These incremental costs drop substantially when comorbidities are included.

CONCLUSIONS:

Obesity and smoking have large long-term impacts on health care costs of working-age adults. Controlling comorbidities impacted incremental costs of obesity but may lead to underestimation of the true incremental costs because obesity is a risk factor for developing chronic conditions.