Adherence to Antihypertensive Therapy With Fixed-Dose Amlodipine Besylate/Benazepril HCl Versus Comparable Component-Based Therapy

Adhering to medication regimens has the potential to significantly improve clinical outcomes for persons with high blood pressure. A patient-related factor likely to affect adherence to treatment is the convenience of the prescribed drug regimen. The authors hypothesized that medication adherence would be superior and cost benefits would accrue in subjects who receive a once-daily, single-capsule, fixed-dose combination product for blood pressure control, compared with subjects who receive a similar regimen of separate components. A managed care organization that provides benefits for members enrolled in various health plans provided the data for this retrospective analysis. The database was used to assess medication adherence patterns for two groups of hypertensive subjects. Group 1 included subjects who had been prescribed the single-capsule, fixed-dose combination of amlodipine besylate/benazepril HCl. Group 2 comprised subjects who had been prescribed a regimen including an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate drugs. Adherence was measured by the medication possession ratio, and medical resource utilization by the two groups was assessed during the study period. Group 1 (n=2754) and Group 2 (n=2978) were balanced with regard to age (mean, 53 years; range, 18-64 years) and sex (men, 50%; women, 50%). The overall medication possession ratio for Group 1 was significantly higher than that for Group 2 (80.8% vs. 73.8%; p<0.001). The average annual cost of cardiovascular-related care per subject was significantly lower in Group 1 compared with Group 2 (p<0.001). Subjects receiving the once-daily, single-capsule, fixed-dose combination of amlodipine/benazepril HCl demonstrated significantly better medication adherence and required fewer medical resources than did subjects receiving an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate components.

Procedure costs and outcomes associated with pharmacologic management of peripheral arterial disease in the Department of Defense

This study was undertaken to determine if differences existed between pharmacologic treatments of peripheral arterial disease (PAD) with respect to PAD-related costs and health care outcomes in the United States Department of Defense health care system. We performed a retrospective review of hospital and prescription data to explore the effects of at least 90 days of aspirin, pentoxifylline, papaverine, or dipyridamole on 4 PAD-related outcomes: number of PAD-related invasive procedures (INV), number of PAD-related examination procedures (EXM), number of PAD-related hospitalization days (HDAYS), and cost of PAD-related procedures (COST) during 5 years. A covariate representing the number of PAD-related hospitalizations before the study period was used to attempt to control for severity of disease state. General linear models were used in the analyses. A statistically significant difference was seen between treatment groups for a linear combination of INV, EXM, HDAYS, and COST when controlling for past PAD-related hospitalizations (P < 0.014). A statistically significant relationship existed between treatment groups and INV (P < 0.041). The pentoxifylline treatment group had a statistically significant higher covariate-adjusted mean INV compared with the aspirin treatment group (P < 0.043). Also, PAD-related past hospitalizations were significantly related to EXM (P < 0.006). Our results appear to support the use of aspirin as a preventive treatment in PAD compared with pentoxifylline or dipyridamole.

The assessment of refill compliance using pharmacy records: methods, validity, and applications

The refill records of computerized pharmacy systems are used increasingly as a source of compliance information. We reviewed the English-language literature to develop a typology of methods for assessing refill compliance (RC), to describe the epidemiology of compliance in obtaining medications, to identify studies that attempted to validate RC measures, to describe clinical features that predicted RC, and to describe the uses of RC measures in epidemiologic and health services research. In most of the 41 studies reviewed, patients obtained less medication than prescribed; gaps in treatment were common. Of the studies that assessed the validity of RC measures, most found significant associations between RC and other compliance measures, as well as measures of drug presence (e.g., serum drug levels) or physiologic drug effects. Refill compliance was generally not correlated with demographic characteristics of study populations, was higher among drugs with fewer daily doses, and was inconsistently associated with the total number of drugs prescribed. We conclude that, though some methodologic problems require further study, RC measures can be a useful source of compliance information in population-based studies when direct measurement of medication consumption is not feasible.