{
  "id": "studies:danish-cohort-2011",
  "collection": "studies",
  "slug": "danish-cohort-2011",
  "name": "Danish cohort study of mobile subscribers (2011 update)",
  "summary": "A nationwide cohort using subscription records rather than recall found no elevated brain tumour incidence among long-term subscribers, including those with 13 or more years of subscription.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "authors": "Frei P, Poulsen AH, Johansen C, et al.",
    "year": 2011,
    "design": "cohort",
    "exposure": "Mobile phone subscription duration from operator records, Danish population",
    "finding": "No increased risk of tumours of the central nervous system among long-term subscribers.",
    "limitations": "Subscription is a crude proxy for use: corporate subscriptions were excluded and non-subscribing users misclassified, both of which dilute any true effect. No data on call time or on which side of the head was used.",
    "weight": "high",
    "url": "https://www.bmj.com/content/343/bmj.d6387",
    "related": [
      "studies:interphone-2010"
    ]
  },
  "sources": [
    {
      "id": "danish-cohort-2011",
      "title": "Use of mobile phones and risk of brain tumours: update of Danish cohort study",
      "publisher": "BMJ",
      "url": "https://www.bmj.com/content/343/bmj.d6387",
      "year": 2011,
      "kind": "peer-reviewed",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/studies/danish-cohort-2011",
    "html": "https://emfbase.com/studies/danish-cohort-2011",
    "markdown": "https://emfbase.com/studies/danish-cohort-2011.md",
    "collection": "https://emfbase.com/api/studies"
  }
}