A LARGE-SCALE CLUSTER RANDOMIZED TRIAL TO DETERMINE THE EFFECTS OF SODIUM REDUCTION ON STROKE: THE CHINA SALT SUBSTITUTE AND STROKE STUDY (SSaSS)

China Salt Substitute and Stroke Study

Sponsors

Lead sponsor: The George Institute

Collaborator: Peking University
Northwestern University
Imperial College London
China Medical University, China
Changzhi Medical College
Centers for Disease Control and Prevention, China
Ningxia Medical University
Health Science Center of Xi’an Jiaotong University

Source The George Institute
Brief Summary

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.

Overall Status Active, not recruiting
Start Date March 2014
Completion Date August 2020
Primary Completion Date August 2020
Phase N/A
Study Type Interventional
Primary Outcome
Measure Time Frame
Stroke 5 years
Secondary Outcome
Measure Time Frame
Total major vascular events 5 years
Total mortality 5 years
Enrollment 21000
Condition
Intervention

Intervention type: Behavioral

Intervention name: Dietary sodium reduction

Description: Ongoing dietary advice and a supply of a reduced-sodium added-potassium salt substitute

Arm group label: Dietary sodium reduction

Other name: Reduced-sodium added-potassium salt substitute

Eligibility

Criteria:

Inclusion Criteria:

- Disease history

- Prior stroke and/or

- Aged 60 years or over and with uncontrolled high blood pressure (systolic blood pressure >=140 millimeters of mercury (mmHg) at visit if on blood pressure lowering medication; systolic blood pressure>=160 millimeters of mercury (mmHg) if not on blood pressure lowering medication)

- Ownership of a phone by the participant or a household member

Exclusion Criteria:

- Participant or family member is using a potassium-sparing diuretic

- Participant or family member is using a potassium supplement

- Participant or family member has serious renal impairment

- Participant or family member has other reason for concern about use of salt substitute

- Participant eats most meals outside the home

- Participant is not expected to live longer than 6 months from the date of assessment as estimated by the village doctor

- Another family member living in the same household has already been included in the study

Gender: All

Minimum age: N/A

Maximum age: N/A

Healthy volunteers: No

Overall Official
Location
facility
Hebei Province Centre for Disease Control and Prevention | Shijiazhuang, Hebei, 71000, China
China Medical Universtity | Shenyang, Liaoning, 110001, China
Ningxia Medical University | Yinchuan, Ningxia, 750004, China
Xi'an Jiaotong University | Xi'an, Shaanxi, 710049, China
Changzhi Medical Colledge | Changzhi, Shanxi, 046000, China
Location Countries

China

Verification Date

April 2020

Responsible Party

Responsible party type: Sponsor

Keywords
Has Expanded Access No
Condition Browse
Number Of Arms 2
Arm Group

Arm group label: Control

Arm group type: No Intervention

Description: Dietary advice at baseline only

Arm group label: Dietary sodium reduction

Arm group type: Experimental

Description: Dietary advice and reduced-sodium added-potassium salt substitute

Acronym SSaSS
Study Design Info

Allocation: Randomized

Intervention model: Parallel Assignment

Primary purpose: Prevention

Masking: Single (Outcomes Assessor)

Source: ClinicalTrials.gov