OBJECTIVES: To estimate the burden of hypertension to a Fortune 500 employer and to assess patient adherence to prescribed medications. METHODS: The prevalence of hypertension, resources utilized, and direct costs incurred by hypertensive patients in this employer s population were extracted from medical and pharmacy claims data for the period October 1, 1996 to September 30, 1997. Hypertension medication compliance for each patient in the same population was calculated based on the medication possession rate (MPR = number of days supplied for the single longest prescribed anti-hypertensive drug for the study year / 365 days). A patient who had an MPR of <80% was considered noncompliant while an MPR of ?80% was considered compliant. RESULTS: The prevalence rate of hypertension in this employer s population (12.6%) was higher than the comparative MedStat population (9.7%). Of these, 31.1% had hypercholesterolemia and 11.2% had ischemic heart disease in addition to their hypertension. All resource utilization rates and direct costs of hypertensive patients in this employer s population were higher than those of the comparative MedStat population. For example, the cardiovascular-related utilization rates for outpatient visits, hospitalizations, and ER visits were 185.8 (MedStat = 171.3), 12.8 (MedStat = 3.5), and 3.3 (MedStat = 1.5) per 1000 members per year, respectively. The total direct cost payment was approximately $4,833 per hypertension patient per year, again higher than MedStat s $3,721 per annual patient cost. Of the 4,924 hypertensive patients included in these analyses 2,379 (48.3%) were identified as noncompliant and 2,545 (51.7%) were compliant. CONCLUSIONS: These results were presented to the employer s senior management to help them prioritize their health management initiatives. A hypertension disease management program has been developed for this population and will be implemented first quarter of 2000.