{
  "_about": "Shared plain-language glossary for opensourcemed.info and vaccinedatanavigator.org. One definition per term, one sentence where possible, no jargon inside a definition. 'match' lists the surface forms to wrap in prose; the first form is the display term. Keep definitions factual and sourced in the full glossary page, not here.",
  "_updated": "2026-10-31",
  "terms": [
    {
      "id": "vaers",
      "match": ["VAERS", "Vaccine Adverse Event Reporting System"],
      "term": "VAERS",
      "short": "The US Vaccine Adverse Event Reporting System: a database anyone can file a report to after a vaccination.",
      "note": "Reports are unverified and do not establish that the vaccine caused the event."
    },
    {
      "id": "faers",
      "match": ["FAERS", "FDA Adverse Event Reporting System"],
      "term": "FAERS",
      "short": "The US FDA Adverse Event Reporting System: the same idea as VAERS, but for drugs rather than vaccines.",
      "note": "Reporting is voluntary, so counts reflect who reported, not how often an effect happens."
    },
    {
      "id": "eudravigilance",
      "match": ["EudraVigilance"],
      "term": "EudraVigilance",
      "short": "The European Medicines Agency's database of suspected side-effect reports for medicines used in the EU.",
      "note": "Like VAERS and FAERS, it collects suspicions, not confirmed causes."
    },
    {
      "id": "passive-surveillance",
      "match": ["passive surveillance", "spontaneous reporting"],
      "term": "Passive surveillance",
      "short": "Safety monitoring that waits for people to send in reports, rather than actively following a defined group of patients.",
      "note": "It can reveal a signal worth investigating, but it cannot measure how common something is."
    },
    {
      "id": "signal",
      "match": ["safety signal", "disproportionality signal"],
      "term": "Safety signal",
      "short": "A pattern in reported data suggesting a possible link between a product and an event, strong enough to justify a closer look.",
      "note": "A signal is a question, not an answer: most do not survive investigation."
    },
    {
      "id": "prr",
      "match": ["PRR", "proportional reporting ratio"],
      "term": "PRR",
      "short": "Proportional Reporting Ratio: how much more often an event is reported for one product than for all other products in the same database.",
      "note": "A high PRR can come from real risk, from publicity, or from how reports are coded."
    },
    {
      "id": "ror",
      "match": ["ROR", "reporting odds ratio"],
      "term": "ROR",
      "short": "Reporting Odds Ratio: a second way of measuring the same disproportionate reporting that the PRR describes.",
      "note": "Reported alongside the PRR because the two can disagree on sparse data."
    },
    {
      "id": "disproportionality",
      "match": ["disproportionality analysis", "disproportionality"],
      "term": "Disproportionality analysis",
      "short": "Comparing how often an event is reported for one product against the background of every other product in the database.",
      "note": "It is a screening tool for finding things to study, not a measure of risk."
    },
    {
      "id": "background-rate",
      "match": ["background rate", "expected rate"],
      "term": "Background rate",
      "short": "How often a condition occurs anyway in a population, with no exposure involved.",
      "note": "Without it, a raw count of reports cannot be judged high or low."
    },
    {
      "id": "causality-assessment",
      "match": ["causality assessment"],
      "term": "Causality assessment",
      "short": "A structured judgement of whether an exposure plausibly caused an event, weighing timing, dose, biology, alternative explanations and the wider literature.",
      "note": "The judgement is about evidence in populations, not about any one person's case."
    },
    {
      "id": "bradford-hill",
      "match": ["Bradford Hill", "Bradford Hill criteria", "Bradford Hill viewpoints"],
      "term": "Bradford Hill viewpoints",
      "short": "Nine considerations — strength, consistency, specificity, temporality, dose-response, plausibility, coherence, experiment and analogy — used to weigh whether an association is causal.",
      "note": "They are viewpoints to reason through, not a checklist that proves causation."
    },
    {
      "id": "lot",
      "match": ["lot number", "batch number", "lot/batch"],
      "_no_match": "A bare \"lot\" is deliberately not matched: it wrecks ordinary prose (\"a lot of uncertainty\").",
      "term": "Lot (batch)",
      "short": "One manufacturing run of a vaccine, identified by a code printed on the vial.",
      "note": "Report counts per lot are not comparable unless you know how many doses that lot contained."
    },
    {
      "id": "aefi",
      "match": ["AEFI", "adverse event following immunisation", "adverse event following immunization"],
      "term": "AEFI",
      "short": "Adverse Event Following Immunisation: any health problem reported after a vaccination, whether or not the vaccine caused it.",
      "note": "The name describes timing only, which is why causality has to be assessed separately."
    },
    {
      "id": "rct",
      "match": ["randomised controlled trial", "randomized controlled trial", "RCT"],
      "term": "Randomised controlled trial",
      "short": "A study that assigns participants to treatment or control by chance, so the groups differ only in the treatment.",
      "note": "Randomisation is what lets a trial support a causal claim."
    },
    {
      "id": "observational",
      "match": ["observational study"],
      "term": "Observational study",
      "short": "A study that watches what happens in real-world care without assigning who gets what.",
      "note": "Useful for rare or long-term effects, but open to confounding."
    },
    {
      "id": "confounding",
      "match": ["confounding", "confounder"],
      "term": "Confounding",
      "short": "When a third factor is tied to both the exposure and the outcome, creating an association that is not cause and effect.",
      "note": "Example: sicker patients get a drug more often, so the drug looks harmful."
    },
    {
      "id": "druggable-target",
      "match": ["druggable target"],
      "term": "Druggable target",
      "short": "A protein or pathway in the body whose behaviour a medicine could realistically change.",
      "note": "Being druggable says nothing about whether altering it helps patients."
    },
    {
      "id": "repurposing",
      "match": ["drug repurposing", "repurposing"],
      "term": "Drug repurposing",
      "short": "Using a medicine already approved for one condition to treat a different one.",
      "note": "The safety record carries over; the evidence of benefit does not."
    },
    {
      "id": "preprint",
      "match": ["preprint"],
      "term": "Preprint",
      "short": "A research paper published by its authors before independent peer review.",
      "note": "Findings may change or fail review entirely."
    },
    {
      "id": "data-quality-grade",
      "match": ["data-quality grade", "data quality grade"],
      "term": "Data-quality grade",
      "short": "This site's A-to-D rating of how complete and current a country's reported vaccination data is.",
      "note": "A low grade describes the reporting, not the country's vaccination programme."
    }
  ]
}