Cost-effective reduction in stroke

One of the great achievements in public health in the second half of the twentieth century was the massive reduction in stroke mortality in Japan [1,2]. During the period from 1966 to 1994, the mortality of stroke in Japan fell from 223 per 100 000, one of the highest rates documented worldwide by the WHO, to 57 per 100 000, placing it in the company of countries such as Australia, England and Wales, France, Sweden and the United States that have low rates of stroke (Fig. 1) [1,2]. At the same time, the life expectancy in Japan rose, with an average age at death of 80 years among men and 86 years among women at the last report in 2010 [2], placing it among the countries with highest life expectancy [3].FIGURE 1: Stroke mortality in Japan and other countries, 1966–1994. Mortality rates of stroke were estimated using data from world health statistics annual [1] and standardized for age distribution of the world standard population.These achievements have been obtained through reductions in both stroke incidence and fatality rates [4,5]. Reductions in stroke fatality rates are likely to be mainly attributable to improvement in stroke care including medical and surgical treatments. On the contrary, reductions in stroke incidence are likely to be attributable to changes in cardiovascular risk factors [4,5]. Among changes in a number of risk factors, reductions in blood pressure levels have been considered to have played the most important role in the reduction in stroke incidence in Japan [6]. In this context, an accompanying article published in this issue of the Journal of Hypertension throws some interesting light [7]. Yamagishi et al. report on the effectiveness and on the cost-effectiveness of the long-term national hypertension reduction and control program in relation to the prevention of stroke in the prefecture of Akita in north eastern Japan, the region with the highest salt intake and the highest stroke rate in Japan [2,8]. Using a variety of both local community records and national data repositories, including National Health Insurance records, the authors compare stroke rates and costs in two distinct communities, one a high-intervention community and the other a minimal intervention community within Akita prefecture. Their starting hypothesis was that stroke rates would be decreased in the high-intervention community but that the costs would be higher [7]. However, as reported in their article, both stroke rates and overall costs were reduced in the high-intervention community, as the reduction in costs of stroke care, resulting from the reduction in stroke rate, more than offset the increase in costs of the intervention and of more intensive treatment of hypertension [7]. The main differences between the program in the high-intervention and the minimal intervention communities were the presence in the former and absence in the latter, of an intensive patient education system (including individual and group education sessions) and of a community-wide education and publicity campaign conducted through the media. In addition, there was free of charge systematic cardiovascular screening throughout the 24 years of study in the high-intervention community, but for only the first 5 years in the minimal intervention community [7,9]. As a result, there were larger reductions in stroke rates in the full intervention community (from 38 per 1000 during 1964–1969 to 12 per 1000 during 1982–1987) compared with those in the minimal intervention community (from 41 per 1000 to 22 per 1000) [9], whereas cost-saving became apparent after 13 years of observation and averaged $354 per capita over the 24 years of study [7]. Therefore, the authors concluded that the national hypertension detection and control program was beneficial and constituted a cost-effective strategy for reducing the burden of stroke in Japan at that time. There are several limitations to the findings of this study. The data of this article were obtained more than 25 years ago. As the study area was in the region with the highest salt intake and the highest stroke rate in Japan [2,8], the study participants may not be representative of the Japanese population as a whole. As this article did not take into account the changes in other risk factors such as reduction in smoking rates and improvement in socio-economic factors, it is unclear to what extent the hypertension detection and control program per se was responsible for the reduction in stroke and to what extent the reductions observed resulted from other factors, not connected to the active intervention program. The reduction in stroke rates in the minimal intervention region, even though smaller, makes it clear that other factors were also playing a role. It is also uncertain how much of the stroke decrease could be explained by population strategies focusing on community-wide education and publicity campaigns as opposed to clinical strategies focusing on treatment of hypertensive patients, as the full-intervention program included elements of both. Despite these uncertainties, the report from Yamagishi et al. does establish that the active intervention program, focusing on raising awareness of, and improving the treatment of hypertension, was associated with a clear fall in stroke rates in the Akita prefecture and that this was cost-effective [7]. The take home message from this study is that better detection and management of hypertension at community level reduces stroke rates and that this saves more health expenditure than it costs, as the care of patients with stroke is expensive and resource intensive. This message is not only important for countries and regions that are already known to have high stroke rates such as east Asia and eastern Europe, but also for low-income and middle-income countries worldwide, where the ‘second wave’ transition to high rates of cardiovascular disease is well under way. Programs for control of hypertension, enriched by attention to other risk factors such as diabetes, smoking and high cholesterol, are likely to be beneficial for both the health profile and the economic well being of many developing countries where the cardiovascular epidemic is already claiming many victims. The lessons from Japanese programs initiated around half a century ago are salutary for us all. ACKNOWLEDGEMENTS Conflicts of interest J.