Impact of the ALLHAT/JNC7 Dissemination Project on thiazide-type diuretic use

Abstract

Background: Strategies are needed to improve the translation of clinical trial results into practice. We assessed the impact of the ALLHAT/JNC7 Dissemination Project's academic detailing component on thiazide-type diuretic prescribing (ALLHAT indicates Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial; JNC7 indicates the Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure).

Methods: We used 2 national databases available from IMS Health: a physician survey of medications reported for hypertension and a pharmacy dispensing database on antihypertensive medications. At a county level, we correlated medication data with Dissemination Project intensity. Practices before the Dissemination Project in 2004 were compared with those after its completion in 2007. We also examined 2000-2008 national trends.

Results: Academic detailing reached 18 524 physicians in 1698 venues via 147 investigator-educators. We noted an association between ALLHAT/JNC7 academic detailing activities and increased prescribing of thiazide-type diuretics. Physician survey data showed that the percentage of hypertension visits where the physician recorded a thiazide-type diuretic increased the most in counties where academic detailing activity was the highest (an increase of 8.6%, from 37.9% to 46.5%) compared with counties where activity was moderate (an increase of 2%) or low (a decrease of 2%), or where there was none (an increase of 2%; P value for trend, <.05). Pharmacy dispensing data showed that thiazide-type diuretic prescribing increased by 8.7% in counties with Dissemination Project activities compared with 3.9% in those without activities (P < .001). Nationally, thiazide-type diuretic use did not increase between 2004 and 2008.

Conclusions: The ALLHAT/JNC7 Dissemination Project was associated with a small effect on thiazide-type diuretic use consistent with its small dose and the potential of external factors to diminish its impact. Academic detailing may increase physicians' implementation of clinical trial results, thereby making prescribing more consistent with evidence.

Figure 1

Proportion visits with a drug class reported among patients with drug-treated hypertension. IMS Health National Disease and Therapeutics Index, 2000 through 2008. ACEI = angiotensin-converting enzyme inhibitor; CCB = calcium channel blocker, ARB = angiotensin II Type 1 receptor blocker.

Figure 2

Proportion visits with a drug class reported among patients with drug-treated hypertension. IMS Health National Disease and Therapeutics Index, 2000 through 2008. Other classes = alpha adrenergic receptor blockers, potassium-sparing diuretics, loop diuretics, and centrally-acting agents.