Factors associated with antihypertensive prescribing.

OBJECTIVE

To investigate factors associated with treatment approaches to hypertension, a major risk factor for coronary heart and cerebrovascular disease and significant healthcare problem in the US. The study reports on three cross-sectional national surveys of patient-physician encounters.

POPULATION

Visits were selected for adults with hypertension diagnoses from the National Ambulatory Medical Care Surveys, which represent office encounters during a given year. Years of observation included 1989, 1990, and 1991.

METHODS

Multiple variable logistic regression was used to identify predisposing need, enabling, and health utilization characteristics associated with whether the visit resulted in a prescription of an antihypertensive. Additionally, the association of these visits with combination therapy is determined.

RESULTS

For each of the 3 years, 69-75% of the encounters were associated with a prescription for drugs to treat hypertension. Prescribing is consistent with current literature demonstrating decreasing reliance on diuretics and beta-blockers, and increasing reliance on calcium antagonists. Combination therapy decreased as a percentage of prescriptions in 1990 and 1991. Variables associated with receiving an antihypertensive prescription included predisposing characteristics (patient age > 65 y), need characteristics (diagnosis of congestive hear failure [CHF]), and health utilization characteristics (physician specialty, previous diagnosis of hypertension). The most significant variables associated with combination therapy were predisposing characteristics (patient age > 65 y), need (CHF diagnosis, diagnosis of hypertension with end organ involvement), and health utilization characteristics (physician specialty).

CONCLUSIONS

These national estimates reinforce previous regional data regarding the categories of hypertension medications used. Patient visits involving multiple diagnoses, cardiologists, or patients older than 65 years, are more likely to generate prescriptions for combination antihypertensive therapy.