Historically, smoking and obesity have had the greatest impact on disease and mortality rates in the United States. However, the relative importance of the two factors, has evolved significantly in the past two decades.

A 2010 paper by researchers from Columbia University and the City College of New York, “Trends in Quality-Adjusted Life-Years Lost Contributed by Smoking and Obesity,” looks at the change in quality-adjusted life-years (QALYs) based on a large sample of U.S. adults from 1993 to 2008. QALYs are measured on a qualitative basis, based on individuals’ perception of their quality of life.

The paper’s key findings include:

• During the years studied, the proportion of smokers among U.S. adults declined from 22.7% to 18.5%.
• During the same period, the proportion of patients who were obese increased from 14.5% to 26.7%.
• Smoking accounted for a relatively stable rate of 0.0436 QALYs lost per population.
• QALYs lost for obesity more than doubled, increasing from 0.0204 in 1993 to 0.0464 in 2008, surpassing smoking.
• Smoking had a larger impact on mortality than disease, while obesity had a greater effect on disease than mortality.

The authors states that the methodology employed in the paper can be extended to the national, state and local levels for health disparities examinations and health care progress evaluations.

Tags: medicine, obesity