Quantifying risk of adverse clinical events with one set of vital signs among primary care patients with hypertension

BACKGROUND: Hypertension is often uncontrolled. One reason might be physicians' reticence to modify therapy in response to single office measurements of vital signs. METHODS: Using electronic records from an inner-city primary care practice, we extracted information about vital signs, diagnoses, test results, and drug therapy available on the first primary care visit in 1993 for patients with hypertension. We then identified multivariable predictors of subsequent vascular complications in the ensuing 5 years. RESULTS: Of 5,825 patients (mean age 57 years) previously treated for hypertension for 5.6 years, 7% developed myocardial infarctions, 17% had strokes, 24% developed ischemic heart disease, 22% had heart failure, 12% developed renal insufficiency, and 13% died in 5 years. Controlling for other clinical data, a 10-mmHg increase in systolic blood pressure was associated with 13% increased risk (95% confidence interval CI], 6%-21%) of renal insufficiency, 9% (95% CI, 3%-15%) increased risk of ischemic heart disease, 7% (95% CI, 3%-11%) increased risk of stroke, and 6% (95% CI, 2%-9%) increased risk of first stroke or myocardial infarction. A 10-mmHg elevation in mean blood pressure predicted a 12% (95% CI, 5%-20%) increased risk of heart failure. An increase in heart rate of 10 beats per minute predicted a 16% (95% CI, 2%-5%) increased risk of death. Diastolic blood pressure predicted only a 13% (95% CI, 4%-23%) increased risk of first stroke. CONCLUSIONS: Vital signs-especially systolic blood pressure-recorded routinely during a single primary care visit had significant prognostic value for multiple adverse clinical events among patients treated for hypertension and should not be ignored by clinicians.