According to the U.S. Agency for Healthcare Research and Quality (AHRQ), more than half
of all hospital patients have "comorbidities"co-existing diseases which are not the main reason
they were hospitalized, but which can complicate treatment and lengthen their stays.
One in three hospital patients has two or more comorbidities. A fifth have hypertension, or
high blood pressure, in addition to their principal diagnosis. Hypertension can complicate treatment of
a principal diagnosis, for example, by increasing the risk of a complicating stroke or heart attack. The second most common comorbiditypresent in roughly 14 percent of patientsare fluid and electrolyte disorders. These are, for example, abnormalities in a patient's potassium or sodium level, and they
may indicate that the patient is significantly dehydrated. These disorders can complicate a hospital stay by increasing the risk of a complicating heart arrhythmia or unstable blood pressure.
Nearly 11 percent of hospital patients suffer from emphysema or chronic bronchitischronic lung diseases that can increase the risk of a complicating pneumonia during a hospital stay. Almost
10 percent have diabetes mellitus, and about 7 percent have an irregular heartbeat.
These statistics on comorbidities are derived from a comprehensive AHRQ report, Hospitalization in the United States, 1997, which is available free of charge in this Vidyya issue and from the AHRQ Publications Clearinghouse, P.O. Box 8547, Silver Spring, MD 20907.
Select to access a chart of the five most common comorbidities among hospital patients for reproduction, 8 KB.