Chronic Disease

Electronic health records help identify patients with hypertension and cardiac problems

Determining a patient's risk for hypertension (high blood pressure) typically involves measuring blood pressure, while determining their likelihood of cardiovascular problems involves identification of risk factors such as cholesterol levels and tobacco use. Electronic health records (EHR) can provide more detailed information on hypertension and make cardiovascular risk stratification automatic, according to two new studies supported by the Agency for Healthcare Research and Quality (HS15647) and led by Stephen D. Persell, M.D., M.P.H., of Northwestern University. The first study found that EHR data can be used to develop measures better able to determine who has uncontrolled blood pressure. In the second study, EHR data allowed for the automatic calculation of cardiovascular risk stratification, thus identifying more patients who can benefit from cholesterol-lowering drugs and other interventions. Both studies are described here.

Persell, S. D., Kho, A. N., Thompson, J. A., and Baker, D. W. (April 2009). "Improving hypertension quality measurement using electronic health records," Medical Care 47(4), pp. 388-394.

In this study, the researchers looked at 5,905 adults with hypertension and 3 or more internal medicine clinic visits. Simple control of blood pressure was defined as the patient's last reading of less than 140/90 mm Hg (less than 130/80 mm Hg, if the patient had diabetes). This simple baseline measurement was compared with more sophisticated blood pressure measures determined at subsequent visits. These were determined from an analysis of the EHR and included changing the definition of blood pressure control, medical management, and undiagnosed hypertension. Among patients without diabetes, using the simple measurement approach demonstrated a 58.1 percent rate of control at baseline. Quality performance was raised to 75.4 percent when patients with adequate control were included, whose last or mean blood pressure was at or below goal. Including patients receiving aggressive treatment increased control to 82.5 percent. Quality performance increases were also observed for patients with diabetes when more elaborate hypertension measures were included.

Persell, S. D., Dunne, A. P., Lloyd-Jones, D. M., and Baker, D. W. (April 2009). "Electronic health record-based cardiac risk assessment and identification of unmet preventive needs," Medical Care 47(4), pp. 418-424.

This study tracked 23,111 adults receiving care at a large primary care practice using an EHR. Using automated assessments of cardiovascular risk, the researchers classified patients into four cardiac risk groups. A separate, manual review was conducted on 100 patients in each group and on those deemed unclassified by a physician. Using the EHR identified 9.2 percent of patients as candidates for cholesterol-lowering therapy and 8 percent of patients eligible for blood-thinning medications. When the researchers compared the automated findings with those from the physician manual review, they found a high level of agreement. Data elements common to those found in commercial EHR systems are able to estimate cardiovascular risk very accurately. Adoption of these automated techniques has the ability to identify patients who may be overlooked when their cardiovascular risk is assessed through more traditional methods, conclude the researchers.

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