In the later years of life, chronic diseases and other health problems tend to accumulate and negatively affect an individual?s health, according to reports published in the latest issue of the Journal of Gerontology: Medical Sciences (Vol. 62A, No. 3).
In a special section devoted to the presence of coexisting medical conditions ? known as comorbidity ? this edition of the journal features four separate articles on the topic.
New diagnoses of common health problems add complexity to an older person?s health status, which is usually characterized by preexisting problems. In 1999, 24 percent of Medicare beneficiaries age 65 or older had four or more chronic conditions. The proportion was 31.4 percent among those 85 or older.
The authors outline a need to improve the understanding of the role of multiple comorbid conditions in the health of older adults. A comprehensive nosology, or classification, of comorbidity is their first step towards this goal.
The nosology begins with physiologic systems (e.g., cardiovascular, endocrine) and assesses each system in several domains (e.g., coronary blood flow, systemic blood pressure, and cardiac function in the cardiovascular system). Functioning in each domain can range from high-functioning, even protective, zones (e.g., high levels of high-density-lipoprotein cholesterol) to severe dysfunction (as in end-stage disease).
The research presented in the special section was inspired and guided by issues raised at meetings of the NIA?s Task Force on Comorbidity. The Institute itself also provided support for these articles.