Tolerance to Target Doses of Thiazides in Actual Practice: A Feasibility Study

This is a pilot study of a method to compare common, FDA-approved drugs in a clinic. Instead of putting single patients into one of two drug groups, the investigators will assign the doctors who prescribe these drugs for high blood pressure into two groups. One group of doctors has agreed to prescribe mostly ("favor") one drug, chlorthalidone, if that drug would be a good choice for a patient. The other group has agreed to prescribe mostly hydrochlorothiazide. For both groups, they will try to use the doses that were shown to be protective in other trials. If the doctors mostly prescribe the drug they agreed to favor, the investigators will be able to compare outcomes, like heart attacks, in the two groups.

prescribing patterns, thiazide, chlorthalidone, hydrochlorothiazide, target dose, cluster randomized trial

Providers randomized to Favor Chlorthalidone will have agreed to prescribe chlorthalidone for patients who are to be newly prescribed a thiazide for hypertension, whether the thiazide is 1st line or add-on therapy. This cluster designation applies only for patients for whom there is equipoise; providers are expected to deviate if medically indicated for individual patients

Providers randomized to Favor Hydrochlorothiazide will have agreed to prescribe hydrochlorothiazide for patients who are to be newly prescribed a thiazide for hypertension, whether the thiazide is 1st line or add-on therapy. This cluster designation applies only for patients for whom there is equipoise; providers are expected to deviate if medically indicated for individual patients

Providers will be randomized to either Favor Chlorthalidone or Favor Hydrochlorothiazide for patients who are to be newly prescribed a thiazide for hypertension, whether the thiazide is 1st line or add-on therapy. Providers will have agreed to adhere to their assignment for patients for whom there is equipoise, but they are free to deviate if medically indicated for individual patients. There is no requirement to maintain the initial thiazide therapy; it is expected that the regimen may require adjustment over time. The cluster assignment is simply to favor a particular thiazide on initiation of thiazide therapy and attempt to reach the target dose.

Inclusion Criteria: VA prescribers of thiazides for hypertension Exclusion Criteria: at non-participating VA sites