{
  "participant_id": {
    "Description": "Unique BIDS subject label"
  },
  "age": {
    "Description": "Age in years at time of scan"
  },
  "sex": {
    "Description": "Biological sex",
    "Levels": {
      "M": "Male",
      "F": "Female"
    }
  },
  "group": {
    "Description": "Study/cohort of origin",
    "Levels": {
      "IGN_CLBP": "Chronic low back pain patients, IGNITE study",
      "PBRCBD": "Chronic low back pain patients, CBD trial (pre-treatment scan)",
      "PBRKOA_KOA": "Knee osteoarthritis patients",
      "PBRKOA_HC": "Healthy controls"
    }
  },
  "pain_hc": {
    "Description": "Pain vs healthy-control status",
    "Levels": {
      "Pain": "Chronic pain patient (cLBP or KOA)",
      "HC": "Healthy control"
    }
  }
}