The impact of a change in hypertension management guidelines on diuretic use in Japan: trends in antihypertensive drug prescriptions from 2005 to 2011

The Japanese Society of Hypertension (JSH) updated its hypertension management guidelines in 2009. One of the most significant changes with respect to the 2004 version was the stance towards the use of diuretics: in 2004, their use was cautioned against, but in 2009, it was actively promoted. The purpose of this study was to measure the impact of this change in guidelines on prescription patterns for antihypertensive medications, and to investigate the overall trend in the use of antihypertensives. We used monthly claims data obtained from a database company. Data of patients who were 20 or more years old and prescribed antihypertensives were extracted and analyzed. There were 66 223 patients who were prescribed antihypertensives (mean age 53.6 +/- 11.0). Of these, 38 130 were men and 28 093 were women. The two most prescribed classes of antihypertensives were angiotensin receptor blockers, whose usage steadily increased over a 7-year period, and calcium channel blockers. Prescriptions for antihypertensives in these two classes were also more likely to be continued than those for other antihypertensive classes. The prescription rate for diuretics increased from December 2006 (P<0.0001), but the rate of increase was the same before and after 2009 (P=0.09). The clinical guidelines published in 2009 had no apparent impact on the trend of diuretic prescriptions, despite the radical change in stance concerning the use of antihypertensives. Further effort to disseminate the content of these guidelines, so that it is reflected in actual clinical practice, may be warranted.