{
  "release_id": "2b2017b84496b985",
  "id": "cardio:ssass",
  "owner": "cardio",
  "kind": "study",
  "slug": "ssass",
  "name": "China Salt Substitute and Stroke Study (SSaSS)",
  "aliases": [
    "SSaSS",
    "Salt Substitute and Stroke Study"
  ],
  "atlases": [
    "cardio"
  ],
  "summary_plain": "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.",
  "summary_technical": "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.",
  "editorial_state": "draft",
  "last_substantive_edit": "2026-10-12",
  "last_evidence_check": "2026-10-12",
  "next_review_due": null,
  "external_ids": [
    {
      "namespace": "nct",
      "value": "NCT02092090"
    }
  ],
  "navigation": {
    "cardio": {
      "system": [
        "brain"
      ],
      "condition-area": [
        "risk-and-prevention",
        "stroke"
      ]
    }
  },
  "payload": {
    "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.",
    "drug_phase": "not_applicable",
    "registry_statuses": [
      {
        "status": "COMPLETED",
        "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
      }
    ],
    "start_date": {
      "date": "2014-07-09",
      "type": "actual",
      "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
    },
    "primary_completion_date": {
      "date": "2020-09-04",
      "type": "actual",
      "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
    },
    "completion_date": {
      "date": "2020-09-04",
      "type": "actual",
      "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
    },
    "countries": [
      {
        "code": "CN",
        "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
      }
    ],
    "care_setting": {
      "description": "Rural villages in China, 600 of them according to the abstract.",
      "snapshot": "cardio:pubmed-34459569-2026-10-11"
    },
    "stopped_early": null,
    "enrollment": [
      {
        "count": 20996,
        "basis": "enrolled",
        "unit": "participants",
        "snapshot": "cardio:ctgov-nct02092090-2026-10-11"
      },
      {
        "count": 20995,
        "basis": "enrolled",
        "unit": "participants",
        "snapshot": "cardio:pubmed-34459569-2026-10-11"
      },
      {
        "count": 600,
        "basis": "randomized",
        "unit": "villages",
        "snapshot": "cardio:pubmed-34459569-2026-10-11"
      }
    ],
    "arms": [
      {
        "id": "cardio:ssass-arm-salt-substitute",
        "label": "Salt substitute with dietary advice",
        "intervention": "cardio:salt-substitution",
        "description": "Villages whose participants used a salt substitute of 75% sodium chloride and 25% potassium chloride by mass (abstract). The registry describes ongoing dietary advice plus a supply of a reduced-sodium added-potassium salt substitute."
      },
      {
        "id": "cardio:ssass-arm-control",
        "label": "Regular salt",
        "intervention": null,
        "description": "Villages whose participants continued regular salt of 100% sodium chloride (abstract). The registry records dietary advice at baseline only and an arm type of no intervention. No separate intervention entity is recorded for the comparator."
      }
    ],
    "findings": [
      {
        "id": "cardio:f-ssass-stroke-substitute",
        "outcome_id": "core:outcome-stroke",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-salt-substitute",
        "comparator_arm_id": null,
        "claim_id": "cardio:claim-ssass-stroke-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "primary",
        "effect_measure": "stroke rate (events per 1000 person-years)",
        "numeric_value": 29.14,
        "reported_text": "29.14 events per 1000 person-years",
        "unit": "events per 1000 person-years",
        "denominator": null,
        "denominator_status": null,
        "denominator_basis": "Not reported in the abstract: neither person-years nor event counts are given.",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": null,
        "estimate_upper": null,
        "interval_method": null,
        "interval_status": null
      },
      {
        "id": "cardio:f-ssass-stroke-control",
        "outcome_id": "core:outcome-stroke",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-control",
        "comparator_arm_id": null,
        "claim_id": "cardio:claim-ssass-stroke-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "primary",
        "effect_measure": "stroke rate (events per 1000 person-years)",
        "numeric_value": 33.65,
        "reported_text": "33.65 events per 1000 person-years",
        "unit": "events per 1000 person-years",
        "denominator": null,
        "denominator_status": null,
        "denominator_basis": "Not reported in the abstract: neither person-years nor event counts are given.",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": null,
        "estimate_upper": null,
        "interval_method": null,
        "interval_status": null
      },
      {
        "id": "cardio:f-ssass-stroke-rr",
        "outcome_id": "core:outcome-stroke",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-salt-substitute",
        "comparator_arm_id": "cardio:ssass-arm-control",
        "claim_id": "cardio:claim-ssass-stroke-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "primary",
        "effect_measure": "rate ratio, salt substitute against regular salt",
        "numeric_value": 0.86,
        "reported_text": "rate ratio 0.86 (95% CI 0.77 to 0.96), P = 0.006",
        "unit": "ratio",
        "denominator": null,
        "denominator_status": "not_applicable",
        "denominator_basis": "Comparison of the two per-arm rate rows",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": 0.77,
        "estimate_upper": 0.96,
        "interval_method": "95% confidence interval; the abstract does not name the model",
        "interval_status": null
      },
      {
        "id": "cardio:f-ssass-death-substitute",
        "outcome_id": "core:outcome-death-any-cause",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-salt-substitute",
        "comparator_arm_id": null,
        "claim_id": "cardio:claim-ssass-mortality-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "secondary",
        "effect_measure": "death rate from any cause (events per 1000 person-years)",
        "numeric_value": 39.28,
        "reported_text": "39.28 events per 1000 person-years",
        "unit": "events per 1000 person-years",
        "denominator": null,
        "denominator_status": null,
        "denominator_basis": "Not reported in the abstract: neither person-years nor event counts are given.",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": null,
        "estimate_upper": null,
        "interval_method": null,
        "interval_status": null
      },
      {
        "id": "cardio:f-ssass-death-control",
        "outcome_id": "core:outcome-death-any-cause",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-control",
        "comparator_arm_id": null,
        "claim_id": "cardio:claim-ssass-mortality-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "secondary",
        "effect_measure": "death rate from any cause (events per 1000 person-years)",
        "numeric_value": 44.61,
        "reported_text": "44.61 events per 1000 person-years",
        "unit": "events per 1000 person-years",
        "denominator": null,
        "denominator_status": null,
        "denominator_basis": "Not reported in the abstract: neither person-years nor event counts are given.",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": null,
        "estimate_upper": null,
        "interval_method": null,
        "interval_status": null
      },
      {
        "id": "cardio:f-ssass-death-rr",
        "outcome_id": "core:outcome-death-any-cause",
        "context_id": "cardio:ctx-ssass-rural-china-stroke-or-60plus-hbp",
        "arm_id": "cardio:ssass-arm-salt-substitute",
        "comparator_arm_id": "cardio:ssass-arm-control",
        "claim_id": "cardio:claim-ssass-mortality-effect",
        "snapshot_id": "cardio:pubmed-34459569-2026-10-11",
        "endpoint_role": "secondary",
        "effect_measure": "rate ratio, salt substitute against regular salt",
        "numeric_value": 0.88,
        "reported_text": "rate ratio 0.88 (95% CI 0.82 to 0.95), P<0.001",
        "unit": "ratio",
        "denominator": null,
        "denominator_status": "not_applicable",
        "denominator_basis": "Comparison of the two per-arm rate rows",
        "time_window": "Mean follow-up 4.74 years",
        "estimate_lower": 0.82,
        "estimate_upper": 0.95,
        "interval_method": "95% confidence interval; the abstract does not name the model",
        "interval_status": null
      }
    ]
  },
  "content_digest": "6a96af6db76e48c52fcd13b190e58f771bb16cea115e0430c8fef4eeedfb647d",
  "review": {
    "content_digest": "6a96af6db76e48c52fcd13b190e58f771bb16cea115e0430c8fef4eeedfb647d",
    "current": [],
    "conflicting": [],
    "stale": [],
    "inactive": []
  },
  "claims": [],
  "decisions": [],
  "relationships": {
    "outgoing": [
      {
        "predicate": "investigates",
        "label": "Intervention arm",
        "clinical_claim_not_fact": false,
        "other_entity_id": "cardio:salt-substitution",
        "other_entity_in_atlas": true,
        "claim_id": null
      },
      {
        "predicate": "investigates",
        "label": "Primary outcome",
        "clinical_claim_not_fact": false,
        "other_entity_id": "core:stroke",
        "other_entity_in_atlas": true,
        "claim_id": null
      },
      {
        "predicate": "investigates",
        "label": "Sodium reduction",
        "clinical_claim_not_fact": false,
        "other_entity_id": "cardio:high-sodium-intake",
        "other_entity_in_atlas": true,
        "claim_id": null
      },
      {
        "predicate": "sponsored_by",
        "label": "Lead sponsor named in the registry",
        "clinical_claim_not_fact": false,
        "other_entity_id": "core:george-institute",
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        "claim_id": null
      },
      {
        "predicate": "funded_by",
        "label": "Funder named in the abstract",
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        "other_entity_id": "cardio:nhmrc",
        "other_entity_in_atlas": true,
        "claim_id": null
      },
      {
        "predicate": "funded_by",
        "label": "Grant MR/S019669/1 listed by PubMed",
        "clinical_claim_not_fact": false,
        "other_entity_id": "cardio:mrc",
        "other_entity_in_atlas": true,
        "claim_id": null
      },
      {
        "predicate": "results_reported_in",
        "label": "Main results, NEJM 2021",
        "clinical_claim_not_fact": false,
        "other_entity_id": "cardio:pub-ssass-nejm-2021",
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        "claim_id": null
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    ],
    "incoming": []
  },
  "page_path": "studies/ssass/",
  "context_path": "api/v1/context/cardio--ssass.md"
}