The effects of incremental costs of smoking and obesity on health care costs among adults: a 7-year longitudinal study.

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.