{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Covid-19%2B+observational&page=2",
    "query": {
      "intervention": "Covid-19+ observational",
      "page": 2
    },
    "page_size": 10
  },
  "pagination": {
    "page": 2,
    "page_size": 10,
    "total_count": 110,
    "total_pages": 11,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Covid-19%2B+observational&page=3&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Covid-19%2B+observational&page=1&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-05T09:01:16.003Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT04323787",
      "title": "Viral Infection and Respiratory Illness Universal Study[VIRUS]: COVID-19 Registry",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Coronavirus"
      ],
      "interventions": [
        {
          "name": "observational",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Mayo Clinic",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "ALL",
        "summary": "Not listed"
      },
      "enrollment_count": 100000,
      "start_date": "2020-03-30",
      "completion_date": "2025-03-31",
      "has_results": false,
      "last_update_posted_date": "2025-04-27",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 4,
      "location_summary": "Scottsdale, Arizona • Jacksonville, Florida • Chicago, Illinois + 1 more",
      "locations": [
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Jacksonville",
          "state": "Florida"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Rochester",
          "state": "Minnesota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04323787"
    },
    {
      "nct_id": "NCT04471051",
      "title": "An Observational Cohort Trial of Outcomes and Antibody Responses Following Treatment With COVID19 Convalescent Plasma in Hospitalized COVID-19 Patients",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Covid19"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "University of Colorado, Denver",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 255,
      "start_date": "2020-04-30",
      "completion_date": "2020-08-20",
      "has_results": false,
      "last_update_posted_date": "2021-06-09",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 6,
      "location_summary": "Aurora, Colorado • Colorado Springs, Colorado • Denver, Colorado + 2 more",
      "locations": [
        {
          "city": "Aurora",
          "state": "Colorado"
        },
        {
          "city": "Aurora",
          "state": "Colorado"
        },
        {
          "city": "Colorado Springs",
          "state": "Colorado"
        },
        {
          "city": "Denver",
          "state": "Colorado"
        },
        {
          "city": "Fort Collins",
          "state": "Colorado"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04471051"
    },
    {
      "nct_id": "NCT04343898",
      "title": "Study of the Treatment and Outcomes in Critically Ill Patients With COVID-19",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Coronavirus Infection"
      ],
      "interventions": [
        {
          "name": "No intervention",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 5154,
      "start_date": "2020-04-01",
      "completion_date": "2023-07-01",
      "has_results": false,
      "last_update_posted_date": "2023-08-09",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04343898"
    },
    {
      "nct_id": "NCT07781501",
      "title": "Long-Term Study of COVID-19 Infection and Long COVID",
      "overall_status": "RECRUITING",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "SARS CoV-2 Post-Acute Sequelae"
      ],
      "interventions": [
        {
          "name": "This study is observational. Only patients who have previously tested positive for SARS-CoV-2 infection or are experiencing ongoing symptoms.",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "University of North Carolina, Chapel Hill",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "18 Years to 75 Years"
      },
      "enrollment_count": 500,
      "start_date": "2024-09-04",
      "completion_date": "2029-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-09-28",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Chapel Hill, North Carolina",
      "locations": [
        {
          "city": "Chapel Hill",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07781501"
    },
    {
      "nct_id": "NCT04837651",
      "title": "Humoral and T-Cell Responses to COVID-19 Vaccination in Multiple Sclerosis Patients Treated With Ocrelizumab Treated With Ocrelizumab or Natalizumab",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Multiple Sclerosis",
        "Demyelinating Autoimmune Diseases, CNS",
        "Autoimmune Diseases of the Nervous System",
        "Nervous System Diseases",
        "Demyelinating Diseases",
        "Autoimmune Diseases",
        "Immune System Diseases",
        "Pathologic Processes"
      ],
      "interventions": [
        {
          "name": "Elecsys semi-quantitative Anti-SARS-CoV-2 antibody test",
          "type": "DEVICE"
        },
        {
          "name": "T-Detect COVID T-cell blood test",
          "type": "DEVICE"
        }
      ],
      "intervention_types": [
        "DEVICE"
      ],
      "sponsor": "Dragonfly Research, LLC",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "55 Years",
        "sex": "ALL",
        "summary": "18 Years to 55 Years"
      },
      "enrollment_count": 48,
      "start_date": "2021-03-02",
      "completion_date": "2021-07-01",
      "has_results": false,
      "last_update_posted_date": "2021-08-02",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Wellesley, Massachusetts",
      "locations": [
        {
          "city": "Wellesley",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04837651"
    },
    {
      "nct_id": "NCT04847596",
      "title": "A Multicenter Study to Assess Response to COVID-19 Vaccine in Multiple Sclerosis Participants Treated With Ofatumumab",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Relapsing Multiple Sclerosis"
      ],
      "interventions": [
        {
          "name": "Ofatumumab",
          "type": "OTHER"
        },
        {
          "name": "Covid-19 vaccine",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Novartis Pharmaceuticals",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "55 Years",
        "sex": "ALL",
        "summary": "18 Years to 55 Years"
      },
      "enrollment_count": 25,
      "start_date": "2021-05-21",
      "completion_date": "2022-02-18",
      "has_results": false,
      "last_update_posted_date": "2023-01-25",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 4,
      "location_summary": "Phoenix, Arizona • Owosso, Michigan • St Louis, Missouri + 1 more",
      "locations": [
        {
          "city": "Phoenix",
          "state": "Arizona"
        },
        {
          "city": "Owosso",
          "state": "Michigan"
        },
        {
          "city": "St Louis",
          "state": "Missouri"
        },
        {
          "city": "Plainview",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04847596"
    },
    {
      "nct_id": "NCT04545047",
      "title": "Observational Study of Convalescent Plasma for Treatment of Veterans With COVID-19",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Coronavirus Disease 2019 (COVID-19)"
      ],
      "interventions": [
        {
          "name": "COVID-19 convalescent plasma",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "VA Office of Research and Development",
      "sponsor_class": "FED",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "21 Years",
        "maximum_age": "80 Years",
        "sex": "ALL",
        "summary": "21 Years to 80 Years"
      },
      "enrollment_count": 5044,
      "start_date": "2020-05-01",
      "completion_date": "2021-10-01",
      "has_results": true,
      "last_update_posted_date": "2024-04-04",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 2,
      "location_summary": "Boston, Massachusetts • Seattle, Washington",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        },
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04545047"
    },
    {
      "nct_id": "NCT04379544",
      "title": "Prognostic Value of Point of Care Cardiac and Lung Ultrasound in COVID-19",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Coronavirus",
        "Respiratory Failure"
      ],
      "interventions": [
        {
          "name": "Observation only",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "University of Pennsylvania",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "100 Years",
        "sex": "ALL",
        "summary": "18 Years to 100 Years"
      },
      "enrollment_count": 125,
      "start_date": "2020-04-23",
      "completion_date": "2021-12-01",
      "has_results": false,
      "last_update_posted_date": "2023-09-21",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04379544"
    },
    {
      "nct_id": "NCT05063812",
      "title": "Performance of a Remote Monitoring Program for Patients Diagnosed With COVID-19",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Covid19",
        "Infectious Disease",
        "SARS-CoV Infection"
      ],
      "interventions": [
        {
          "name": "Observational",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "George Washington University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "100 Years",
        "sex": "ALL",
        "summary": "18 Years to 100 Years"
      },
      "enrollment_count": 18,
      "start_date": "2020-09-21",
      "completion_date": "2023-12-31",
      "has_results": false,
      "last_update_posted_date": "2024-03-01",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Washington D.C., District of Columbia",
      "locations": [
        {
          "city": "Washington D.C.",
          "state": "District of Columbia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05063812"
    },
    {
      "nct_id": "NCT05022446",
      "title": "The Impact of COVID-19 on Pulmonary Procedures",
      "overall_status": "RECRUITING",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "COVID-19 Infection",
        "Hematopoietic and Lymphoid Cell Neoplasm",
        "Malignant Solid Neoplasm"
      ],
      "interventions": [
        {
          "name": "Survey Administration",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "M.D. Anderson Cancer Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "ALL",
        "summary": "Not listed"
      },
      "enrollment_count": 250,
      "start_date": "2020-11-11",
      "completion_date": "2027-02-02",
      "has_results": false,
      "last_update_posted_date": "2026-08-10",
      "last_synced_at": "2026-10-05T09:01:16.003Z",
      "location_count": 1,
      "location_summary": "Houston, Texas",
      "locations": [
        {
          "city": "Houston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05022446"
    }
  ]
}