# China Salt Substitute and Stroke Study (SSaSS)

Study · id `cardio:ssass` · Cardiovascular Atlas · release `2b2017b84496b985` (public)

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Also called: SSaSS; Salt Substitute and Stroke Study

Browse, organ or system: Brain  
Browse, condition area: Risk and prevention; Stroke  

## In plain language

A large trial in rural China that tested whether replacing ordinary salt with a lower-sodium, potassium-enriched salt reduces strokes. It enrolled people who had had a stroke or who were 60 or older with high blood pressure, in 600 villages. Villages were assigned by chance to the salt substitute or to ordinary salt. Over about 4.7 years there were fewer strokes and fewer deaths in the salt-substitute villages. The results apply to this group in rural China and should not be assumed for other people.

## Technical summary

Open-label (abstract), cluster-randomized trial NCT02092090 in 600 villages, assigned 1:1. Registry enrollment is 20996 and the abstract reports 20,995 enrolled; the reason is unknown. Intervention villages: ongoing dietary advice plus a salt substitute of 75% sodium chloride and 25% potassium chloride by mass; control villages: dietary advice at baseline only (registry) and regular salt (abstract). Primary outcome stroke; secondary outcomes major adverse cardiovascular events (49.09 against 56.29 events per 1000 person-years, rate ratio 0.87, 95% CI 0.80 to 0.94) and death from any cause; safety outcome clinical hyperkalemia. Mean follow-up 4.74 years. Funded by the National Health and Medical Research Council of Australia (abstract). PubMed also lists a grant from the UK Medical Research Council (MR/S019669/1). The registry names The George Institute as lead sponsor. The abstract says open-label while the registry records masking as DOUBLE; not reconciled. No results are posted in the registry. Full text was not accessible, so per-arm event counts and denominators are not recorded.

## Key facts

- Design: Cluster-randomized, parallel-group trial of 600 villages assigned 1:1. The abstract calls it open-label. The registry records allocation as randomized and masking as DOUBLE (investigator and outcomes assessor). The two descriptions are not reconciled. Prevention trial; no drug phase.
- Phase: Not applicable
- Enrolled: 20996 participants (enrolled count; China Salt Substitute and Stroke Study, snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11); 20995 participants (enrolled count; Effect of Salt Substitution on Cardiovascular Events and Death, snapshot `cardio:pubmed-34459569-2026-10-11`, retrieved 2026-10-11); 600 villages (randomized count; Effect of Salt Substitution on Cardiovascular Events and Death, snapshot `cardio:pubmed-34459569-2026-10-11`, retrieved 2026-10-11)
- Started: 2014-07-09 (actual) (China Salt Substitute and Stroke Study, snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11)
- Primary completion: 2020-09-04 (actual) (China Salt Substitute and Stroke Study, snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11)
- Completion: 2020-09-04 (actual) (China Salt Substitute and Stroke Study, snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11)
- Countries: China (China Salt Substitute and Stroke Study, snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11)
- Care setting: Rural villages in China, 600 of them according to the abstract. (Effect of Salt Substitution on Cardiovascular Events and Death, snapshot `cardio:pubmed-34459569-2026-10-11`, retrieved 2026-10-11)
- Registry status: "COMPLETED" (U.S. National Library of Medicine (ClinicalTrials.gov), snapshot `cardio:ctgov-nct02092090-2026-10-11`, retrieved 2026-10-11)

## Study findings

Findings are grouped by the claim they support. Each group keeps its own population and follow-up, and each finding keeps its own denominator and time window. Not reported is not zero.

### In SSaSS, in rural Chinese villages, people who had had a stroke or were 60 or older with high blood pressure had fewer strokes when their village used a lower-sodium, potassium-enriched salt substitute, with ongoing dietary advice, than when it kept using regular salt. Over a mean follow-up of 4.74 years the stroke rate was 29.14 events per 1000 person-years with the substitute and 33.65 with regular salt (rate ratio 0.86, 95% CI 0.77 to 0.96).

Claim `cardio:claim-ssass-stroke-effect`.

Applies to: Recipient: Recipient not specified; Population: People who had had a stroke, or who were 60 years of age or older and had high blood pressure, living in rural villages in China. The registry defines high blood pressure as uncontrolled: systolic 140 mmHg or more on treatment, or 160 mmHg or more without treatment. In the trial 72.6% had a history of stroke and 88.4% a history of hypertension, and the mean age was 65.4 years. No source read gives a minimum age, and the past-stroke group has no stated age floor, so the recipient is recorded as unknown rather than adult. Pregnancy is not mentioned in the sources read.; Care setting: Rural villages in China, 600 of them. The registry names five Northern Chinese provinces and Tibet. A household phone was an entry requirement.; Geography: Rural China: five Northern Chinese provinces and Tibet (registry description); Life stage: Mixed ages with a mean of 65.4 years. Age 60 or over is required for people without a past stroke; no age floor is stated for people with one.; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Mean follow-up 4.74 years (abstract). The registry gives a time frame of 5 years.

Limitations: One open-label, cluster-randomized trial in rural China. The result applies to people who had had a stroke or were 60 or over with high blood pressure and met the other entry rules, such as no potassium-sparing diuretic, potassium supplement or serious kidney impairment in the household. It does not show the same effect in other groups or places. The tested package is ongoing dietary advice plus the substitute, compared with dietary advice at baseline only (registry). The abstract calls the trial open-label, while the registry records masking as DOUBLE (investigator and outcomes assessor); the two are not reconciled. The registry counts 20996 participants and the abstract 20,995; the reason is unknown. Only the abstract and the registry were read: the NEJM full text returned HTTP 403 and no open copy exists, so event counts, person-years, per-arm intervals and any correction are not recorded.

- Stroke as an outcome (Primary): Stroke rate (events per 1000 person-years) 29.14 events per 1000 person-years; reported as "29.14 events per 1000 person-years"; arm Salt substitute with dietary advice, no comparator arm; interval Not reported; denominator Not reported (basis: Not reported in the abstract: neither person-years nor event counts are given.); time window Mean follow-up 4.74 years
- Stroke as an outcome (Primary): Stroke rate (events per 1000 person-years) 33.65 events per 1000 person-years; reported as "33.65 events per 1000 person-years"; arm Regular salt, no comparator arm; interval Not reported; denominator Not reported (basis: Not reported in the abstract: neither person-years nor event counts are given.); time window Mean follow-up 4.74 years
- Stroke as an outcome (Primary): Rate ratio, salt substitute against regular salt 0.86 ratio; reported as "rate ratio 0.86 (95% CI 0.77 to 0.96), P = 0.006"; arm Salt substitute with dietary advice compared with Regular salt; interval 0.77 to 0.96 (95% confidence interval; the abstract does not name the model); denominator Not applicable (basis: Comparison of the two per-arm rate rows); time window Mean follow-up 4.74 years

### In the same trial and time window, deaths from any cause were less frequent with the salt substitute: 39.28 events per 1000 person-years against 44.61 with regular salt (rate ratio 0.88, 95% CI 0.82 to 0.95). Death from any cause was a secondary outcome.

Claim `cardio:claim-ssass-mortality-effect`.

Applies to: Recipient: Recipient not specified; Population: People who had had a stroke, or who were 60 years of age or older and had high blood pressure, living in rural villages in China. The registry defines high blood pressure as uncontrolled: systolic 140 mmHg or more on treatment, or 160 mmHg or more without treatment. In the trial 72.6% had a history of stroke and 88.4% a history of hypertension, and the mean age was 65.4 years. No source read gives a minimum age, and the past-stroke group has no stated age floor, so the recipient is recorded as unknown rather than adult. Pregnancy is not mentioned in the sources read.; Care setting: Rural villages in China, 600 of them. The registry names five Northern Chinese provinces and Tibet. A household phone was an entry requirement.; Geography: Rural China: five Northern Chinese provinces and Tibet (registry description); Life stage: Mixed ages with a mean of 65.4 years. Age 60 or over is required for people without a past stroke; no age floor is stated for people with one.; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Mean follow-up 4.74 years (abstract). The registry gives a time frame of 5 years.

Limitations: Secondary outcome. The limits of the stroke claim apply: One open-label, cluster-randomized trial in rural China. The result applies to people who had had a stroke or were 60 or over with high blood pressure and met the other entry rules, such as no potassium-sparing diuretic, potassium supplement or serious kidney impairment in the household. It does not show the same effect in other groups or places. The tested package is ongoing dietary advice plus the substitute, compared with dietary advice at baseline only (registry). The abstract calls the trial open-label, while the registry records masking as DOUBLE (investigator and outcomes assessor); the two are not reconciled. The registry counts 20996 participants and the abstract 20,995; the reason is unknown. Only the abstract and the registry were read: the NEJM full text returned HTTP 403 and no open copy exists, so event counts, person-years, per-arm intervals and any correction are not recorded.

- Death from any cause (Secondary): Death rate from any cause (events per 1000 person-years) 39.28 events per 1000 person-years; reported as "39.28 events per 1000 person-years"; arm Salt substitute with dietary advice, no comparator arm; interval Not reported; denominator Not reported (basis: Not reported in the abstract: neither person-years nor event counts are given.); time window Mean follow-up 4.74 years
- Death from any cause (Secondary): Death rate from any cause (events per 1000 person-years) 44.61 events per 1000 person-years; reported as "44.61 events per 1000 person-years"; arm Regular salt, no comparator arm; interval Not reported; denominator Not reported (basis: Not reported in the abstract: neither person-years nor event counts are given.); time window Mean follow-up 4.74 years
- Death from any cause (Secondary): Rate ratio, salt substitute against regular salt 0.88 ratio; reported as "rate ratio 0.88 (95% CI 0.82 to 0.95), P<0.001"; arm Salt substitute with dietary advice compared with Regular salt; interval 0.82 to 0.95 (95% confidence interval; the abstract does not name the model); denominator Not applicable (basis: Comparison of the two per-arm rate rows); time window Mean follow-up 4.74 years

## Connected pages

- Intervention arm: Salt substitution (lower-sodium, potassium-containing salt) (`cardio:salt-substitution`)
- Primary outcome: Stroke (`core:stroke`)
- Sodium reduction: High sodium intake (`cardio:high-sodium-intake`)
- Lead sponsor named in the registry: The George Institute for Global Health (`core:george-institute`)
- Funder named in the abstract: National Health and Medical Research Council of Australia (`cardio:nhmrc`)
- Grant MR/S019669/1 listed by PubMed: Medical Research Council (United Kingdom) (`cardio:mrc`)
- Main results, NEJM 2021: SSaSS main results, NEJM 2021 (`cardio:pub-ssass-nejm-2021`)

## Provenance

Content hash: 6a96af6db76e48c52fcd13b190e58f771bb16cea115e0430c8fef4eeedfb647d
Last substantive edit: 2026-10-12
Evidence last checked: 2026-10-12