02990nas a2200493   4500000000100000008004100001653001100042653001100053653000900064653002200073653000900095653001700104653001700121653001000138653001400148653002000162653001100182653001700193653001900210653001400229653002600243653002800269100001100297700001600308700001400324700001700338700001700355700001500372700001500387700002100402700001500423700001900438700001800457700001700475700001800492700001500510700002000525700001500545245015100560300001200711490000800723520175100731022001402482       2017                            d10aFemale10aHumans10aAged10aFollow-Up Studies10aMale10aRisk Factors10aHypertension10aChina10aIncidence10aRisk Assessment10aStroke10aTime Factors10aBlood Pressure10apotassium10aRetrospective Studies10aDiet, Sodium-Restricted1 aTian M1 aWu Yangfeng1 aLi Nicole1 aElliott Paul1 aHuang Liping1 aYin Xuejun1 aHao Zhixin1 aStepien Sandrine1 aShi Jingpu1 aFeng Xiangxian1 aZhang Jianxin1 aZhang Yuhong1 aZhang Ruijuan1 aYan Lijing1 aLabarthe Darwin1 aNeal Bruce00aRationale, design, and baseline characteristics of the Salt Substitute and Stroke Study (SSaSS)-A large-scale cluster randomized controlled trial.  a109-1170 v1883 a<p>
Lowering sodium intake with a reduced-sodium, added potassium salt substitute has been proved to lower blood pressure levels. Whether the same strategy will also reduce the risks of vascular outcomes is uncertain and controversial. The SSaSS has been designed to test whether sodium reduction achieved with a salt substitute can reduce the risk of vascular disease. The study is a large-scale, open, cluster-randomized controlled trial done in 600 villages across 5 provinces in China. Participants have either a history of stroke or an elevated risk of stroke based on age and blood pressure level at entry. Villages were randomized in a 1:1 ratio to intervention or continued usual care. Salt substitute is provided free of charge to participants in villages assigned to the intervention group. Follow-up is scheduled every 6months for 5years, and all potential endpoints are reviewed by a masked adjudication committee. The primary end point is fatal and nonfatal stroke, and the 2 secondary endpoints are total major cardiovascular events and total mortality. The study has been designed to provide 90% statistical power (with 2-sided α = .05) to detect a 13% or greater relative risk reduction for stroke. The power estimate assumes a primary outcome event rate of 3.5% per year and a systolic blood pressure difference of 3.0mm Hg between randomized groups. Recruitment is complete and there are 20,996 participants (about 35 per village) that have been enrolled. Mean age is 65years and 49% are female. There were 73% enrolled on the basis of a history of stroke. The trial is well placed to describe the effects of salt substitution on the risks of vascular disease and death and will provide important policy-relevant data.
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