Abstract
BACKGROUND: A range of first-line similarly effective medications ranging in price are recommended for treating uncomplicated hypertension. Considering drug costs alone, thiazides and thiazide-like diuretics are the most cost-efficient option. We determined incident prescribing of thiazides for newly diagnosed hypertension as first-line treatment in Alberta, factors that predicted receiving thiazides vs more costly medications, and how much could be saved if more patients were prescribed thiazides. METHODS: Using a retrospective cohort design, factors predicting receiving thiazides vs other agents were determined using mixed effects logistic regression. Cost savings were simulated by shifting patients from other antihypertensive medications to thiazides and calculating the difference. RESULTS: Within our cohort of 89,548 adults, only 12% received thiazides as first-line treatment whereas 44% received angiotensin converting enzyme inhibitors, 17% received angiotensin receptor blockers, 16% received calcium channel blockers, and 10% received β-blockers. Antihypertensive medications were typically prescribed by office-based, general practitioners (88%). Being male and receiving a prescription from a physician with ≥ 20 years of practice and a high clinical workload were associated with increased odds of receiving nonthiazides. In the extreme case that all patients received thiazides as their first prescription, spending would have been reduced by a maximum of 95% (CAD$1.8 million). CONCLUSIONS: Only 12% of Albertan adults with incident, uncomplicated hypertension were prescribed thiazides as first-line treatment. With the opportunity for drug cost savings, future research should evaluate the risk of adverse events and side effects across the drug classes and whether the costs associated with managing those risks could offset the savings achieved through increased thiazide use.