Date of Award
Doctor of Philosophy in Pharmaceutical Sciences
Susan E. Andrade
Hypertension is a common chronic disease, which is expensive to treat and has serious but preventable long-term complications. It should be possible to optimize antihypertensive therapy such that the most prevention is obtained with the least cost. This optimization can be approached through adherence to current national evidence-based practice guidelines for the treatment of hypertension.
The objectives of this study are: (1) to test hypotheses regarding comorbidities and prescribing in hypertension and, (2) to identify opportunities to improve adherence to treatment guidelines for hypertension.
The study employs a nonconcurrent cohort research design for hypothesis testing in incident uncomplicated cases of hypertension. The practice recommendations from the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure were translated into operational definitions of uncomplicated hypertension, relevant comorbidities, and drug class prescribing. Administrative claims data were used to classify cases with respect to diseases and classes. These classifications were used to test for predicted disease-class associations.
Multivariate adjusted odds ratios (OR) and 95% confidence intervals (Cl) for significant associations include: Angiotensin Converting Enzyme (ACE) inhibitor (5.88 OR, 2.57-13.43 Cl) and diuretic (10.87 OR, 4.70-25.15 Cl) prescribing positively associated with congestive heart failure; betablocker (4.39 OR, 2.93-6.56 95% Cl) and calcium channel blocker (CCB) (2.70 OR, 1.88-3.86) prescribing positively associated with coronary artery disease; beta-blocker prescribing negatively associated with chronic obstructive pulmonary disease (0.50 OR, 0.33-0.75 Cl) and diabetes mellitus (0.56 OR, 0.38-0.82 Cl); and ACE inhibitor prescribing positively associated with diabetes mellitus (1 .73 OR, 1.38-2.16 Cl). Additional significant associations were found in bivariate analyses reported as unadjusted relative risks (RR) and 95% confidence intervals (Cl) including: a positive association of ACE inhibitor prescribing in renal failure (1.84 RR, 1.11-3.04 Cl) and negative associations between diuretic (0.69 RR, 0.58-0.83 Cl) and beta-blocker (0.62 RR, 0.50-0.77 Cl) prescribing with dyslipidemia. Diuretics and beta-blockers (38.8%) are not used more frequently as first line therapy than CCBs and ACE inhibitors (59.7%) in uncomplicated hypertension.
The predicted associations were largely confirmed, providing evidence for appropriate prescribing in hypertension. Analysis of claims data can be a useful method of measuring prescribing practices in hypertension. The details of this methodology and its limitations are discussed. The major opportunity for improvement relates to under-prescribing of diuretics and beta-blockers, and over-prescribing of calcium channel blockers and ACE inhibitors in uncomplicated hypertension.
Westrick, Edward Roy, "Antihypertensive Pharmacotherapy: Does Prescribing Follow National Guideline Recommendations?" (1999). Open Access Dissertations. Paper 191.