China Salt Substitute and Stroke Study "SSaSS"

Active, not recruiting

Phase N/A Results N/A

Trial Description

The study is a large scale cluster randomised trial to evaluate the effects of sodium reduction based upon the use of salt substitute on the risk of stroke defined as the occurrence of stroke and stroke deaths. The corresponding null hypothesis that will be tested is that sodium reduction will have no effect upon stroke risk. The secondary objectives are to determine effects of sodium reduction on major vascular events and total mortality.

Detailed Description

Lowering sodium intake and the use of salt substitute have been proved to lower blood pressure levels. Effects on the risks of vascular outcomes have not been defined in an adequately powered randomised trial. Rural Chinese are known to consume very large quantities of sodium and to suffer from very high rates of hypertension and stroke. This study is a large scale cluster randomised trial done in rural areas of China. The study will define the effects of a salt substitute-based sodium reduction strategy on the primary outcome of stroke. Secondary endpoints will include major cardiovascular events and total mortality. The study will be conducted in 600 rural villages across five Northern Chinese provinces and Tibet. The study will recruit 35 individuals at elevated risk of stroke from each village for a total of 21,000 participants. The participating villages will be randomised into intervention and control group with 1:1 allocation. Recruitment will prioritise individuals with a history of stroke but also include older individuals with high blood pressure. Follow up is scheduled for 5 years. Individuals in intervention villages will receive repeated dietary advice and a supply of low sodium salt substitute while individuals in control villages will receive dietary advice at baseline only. Every 6 months throughout follow-up each individual will be contacted by phone call to inquire about the occurrence of stroke, hospitalisation for any cause and diagnoses of any other serious illnesses. The interview will be structured and done by individuals masked to the randomised assignment of each individual. For all deaths identified and all events that might possibly be non-fatal strokes a home visit will be made. A series of process indicators including urinary sodium, urinary potassium, blood pressure, knowledge about sodium and use of salt substitute will also be measured on a random sample of at least 20 individuals drawn from a random selection of 60 villages at baseline and every year thereafter.

Conditions

Interventions

  • Dietary sodium reduction Behavioral
    Other Names: Reduced-sodium added-potassium salt substitute
    Intervention Desc: Ongoing dietary advice and a supply of a reduced-sodium added-potassium salt substitute
    ARM 1: Kind: Experimental
    Label: Dietary sodium reduction
    Description: Dietary advice and reduced-sodium added-potassium salt substitute

Trial Design

  • Allocation: Randomized
  • Masking: Single Blind (Outcomes Assessor)
  • Purpose: Prevention
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Stroke 5 years No
Secondary Total major vascular events 5 years No
Secondary Total mortality 5 years No

Sponsors