{
  "schemaVersion": 1,
  "id": "https://www.crosstabs.com/examples/aspirin-and-heart-attack#dataset",
  "version": "1.0.0",
  "name": "Aspirin and Heart Attack (Physicians' Health Study)",
  "description": "A randomized trial of 22,071 US male physicians: did low-dose aspirin reduce the rate of first myocardial infarction versus placebo?",
  "field": "medicine",
  "question": "Did low-dose aspirin reduce first heart attacks versus placebo?",
  "takeaway": "Heart attacks were less frequent in the randomized aspirin arm, although the absolute difference was small.",
  "datePublished": "2026-06-10",
  "dateModified": "2026-07-31",
  "provenance": {
    "kind": "derived",
    "citation": "Steering Committee of the Physicians' Health Study Research Group (1989). Final report on the aspirin component of the ongoing Physicians' Health Study. New England Journal of Medicine, 321(3), 129–135.",
    "sourceUrl": "https://www.nejm.org/doi/full/10.1056/NEJM198907203210301"
  },
  "variables": {
    "row": {
      "name": "Treatment",
      "categories": [
        "Aspirin",
        "Placebo"
      ]
    },
    "column": {
      "name": "Myocardial infarction",
      "categories": [
        "Heart attack",
        "No heart attack"
      ]
    }
  },
  "counts": [
    [
      104,
      10933
    ],
    [
      189,
      10845
    ]
  ]
}