176065 Bridging demography, epidemiology, and statistics: Acceleration in disease rates with age- The SIMPLE Method

Wednesday, October 29, 2008: 11:00 AM

Steven A. Cohen, MPH , Department of Population, Family, and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
Elena Naumova, PhD , Department of Public Health and Community Medicine, Tufts School of Medicine, Boston, MA
Selection of appropriate summary measures that accurately and precisely capture not only disease burden, but also population structure and dynamics that contribute to disease patterns is challenging. Some of the common measures of disease burden in the elderly, such as age-adjusted rates and age-categorization of rates, while useful, can mask important population processes that contribute to such disease patterns, especially in the elderly. We used Medicare hospitalization data (1991-2004) and US Census Bureau counts to estimate age-specific, influenza-related hospitalization incidence in the elderly by influenza season on the state and regional levels. We observed that incidence increases exponentially with age, and therefore proposed a technique, the Slope Intercept Modeling for Population Linear Estimation (SIMPLE) method, that represented that trend by two parameters. There parameters consist of an intercept, which represents expected influenza incidence at age 65, and a slope, which represents the degree of exponential increase of influenza-related incidence by age for the elderly. R-squared values for these models ranged from 0.802 to 0.989 for states and between 0.935 and 0.995 for regions. These results suggest spatiotemporal trends in influenza-related cases in the elderly can be estimated accurately and precisely using the SIMPLE method. This method produces two meaningful and relevant measures that can be used as summary measures of disease in a population and reflect the underlying demographics and epidemiology of disease, and can be applied to other diseases that exhibit similar age patterns in the elderly population.

Learning Objectives:
1. Recognize and quantify age patterns in disease in the elderly population. 2. Summarize disease rates in a population subgroup in a way that reflects population dynamics and susceptibility into two meaningful and straightforward measures. 3. Develop and expand the use of existing population-based surveillance data to measure disease patterns.

Keywords: Elderly, Infectious Diseases

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have conducted the full analysis on this subject and am responsible for the writing of the abstract and relevant papers related to this topic.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.