Antihypertensive therapy for the elderly: an expert system to assist therapeutic decisions.

The prevalence of hypertension among the elderly is high. Recent multicenter studies have shown hypertension, especially isolated systolic hypertension, to be a risk factor and treatment to be effective, if individualized. In addition, the presence of multiple complicating conditions and the need for multiple medications in the elderly increases the required medical knowledge base necessary to appropriately determine antihypertensive therapy. To assist the primary provider, an expert system has been developed that provides advice on therapeutic decisions for elderly patients (greater than 65 years old and less than 85 years old). It takes into account such factors as age, sex, lifestyle, site of care, nutritional status, physiologic and pathophysiologic changes, co-existing diseases, multiple drug use, and prior antihypertensive drug exposure and response. The system user enters patient characteristics, disease states, risk factors, relevant laboratory values, and prior drug therapy. The system responds with a set of recommendations of appropriate therapy individualized for the specific patient. To further assist the process, relative costs of therapy are also included. The system, consisting of over 200 rules, is currently undergoing validation by a panel of cardiologists. It is implemented in IBM's Expert System Environment (ESE) on the IBM 4341. The authors wish to acknowledge the contribution of the ESE software by the IBM Corporation.