{"id": 1103691, "name": "Average study length by phase", "unit": "days", "createdAt": "2025-08-18T15:51:56.000Z", "updatedAt": "2025-08-18T15:51:56.000Z", "coverage": "", "timespan": "1976-2025", "datasetId": 7190, "shortUnit": "days", "columnOrder": 0, "shortName": "avg_study_length_days", "catalogPath": "grapher/health/2025-07-28/clinical_trials/length_per_year#avg_study_length_days", "descriptionShort": "Median length of completed clinical trials by phase. The phase refers to the phase of drug development the drug is currently in ([early phase 1](#dod:early-phase-one-trial), [phase 1](#dod:phase-one-trial), [phase 2](#dod:phase-two-trial), [phase 3](#dod:phase-three-trial) or [phase 4](#dod:phase-four-trial)). The study length is the time from start date to completion date, given in days.\n", "descriptionProcessing": "- First we calculate the length of each trial by taking the difference between the start date and completion date of each trial.\n- Then we group the trials by phase and completion year, and calculate the [median](#dod:median) length of each group.", "type": "float", "grapherConfigIdETL": "0198bde1-4f4e-7ff4-8f50-28ca4cc543c7", "datasetName": "Clinical Trials (ClinicalTrials.gov)", "updatePeriodDays": 365, "datasetVersion": "2025-07-28", "nonRedistributable": false, "display": {"unit": "days", "shortUnit": "days", "numDecimalPlaces": 0}, "schemaVersion": 2, "processingLevel": "major", "presentation": {"topicTagsLinks": ["Medicine & Biotechnology"]}, "descriptionKey": ["Clinical trials are conducted in different phases of the development of a new treatment or intervention, such as [early phase 1](#dod:early-phase-one-trial), [phase 1](#dod:phase-one-trial), [phase 2](#dod:phase-two-trial), [phase 3](#dod:phase-three-trial), or [phase 4](#dod:phase-four-trial).", "Early phase 1 trials are exploratory trials that test the effect of an intervention on the human body, often with a small number of participants. Not every treatment has an early phase 1 trial.", "Phase 1 trials test the safety and dosage of a new treatment, phase 2 trials test the effectiveness and side effects, and phase 3 trials compare the new treatment to standard treatments.", "Phase 4 trials are conducted after a treatment has been approved and are used to monitor the long-term effects and side-effects of the treatment. Not every treatment has a phase 4 trial.", "\\\"Phase 1/phase 2\\\" trials are a combination of phase 1 and phase 2 trials, and \"phase 2/phase 3\" trials are a combination of phase 2 and phase 3 trials.", "The average length is calculated by taking the difference between the start date and completion date of each trial, grouped by phase and completion year.", "This data comes from the [ClinicalTrials.gov](#dod:clinical-trials-gov) database. It only includes [interventional clinical trials](#dod:interventional-trial) that are marked as \"completed\" and have a valid \"completion date\".", "Registration in the ClinicalTrials.gov database is mandatory for trials in the United States and for treatments that seek FDA approval, but voluntary for other trials conducted in other countries."], "dimensions": {"years": {"values": [{"id": 1976}, {"id": 1979}, {"id": 1980}, {"id": 1981}, {"id": 1982}, {"id": 1983}, {"id": 1985}, {"id": 1986}, {"id": 1987}, {"id": 1988}, {"id": 1989}, {"id": 1990}, {"id": 1991}, {"id": 1992}, {"id": 1993}, {"id": 1994}, {"id": 1995}, {"id": 1996}, {"id": 1997}, {"id": 1998}, {"id": 1999}, {"id": 2000}, {"id": 2001}, {"id": 2002}, {"id": 2003}, {"id": 2004}, {"id": 2005}, {"id": 2006}, {"id": 2007}, {"id": 2008}, {"id": 2009}, {"id": 2010}, {"id": 2011}, {"id": 2012}, {"id": 2013}, {"id": 2014}, {"id": 2015}, {"id": 2016}, {"id": 2017}, {"id": 2018}, {"id": 2019}, {"id": 2020}, {"id": 2021}, {"id": 2022}, {"id": 2023}, {"id": 2024}, {"id": 2025}]}, "entities": {"values": [{"id": 371906, "name": "Phase 3", "code": null}, {"id": 371910, "name": "Phase 4", "code": null}, {"id": 371909, "name": "Phase 2", "code": null}, {"id": 371905, "name": "Phase 1", "code": null}, {"id": 371907, "name": "Phase 2/3 (combined)", "code": null}, {"id": 371908, "name": "Phase 1/2 (combined)", "code": null}, {"id": 371911, "name": "Early phase 1", "code": null}]}}, "origins": [{"id": 7011, "title": "Clinical Trials (ClinicalTrials.gov)", "description": "ClinicalTrials.gov is a website and online database of clinical research studies and information about their results. The purpose of ClinicalTrials.gov is to provide information about clinical research studies to the public, researchers, and health care professionals.", "producer": "ClinicalTrials.gov", "citationFull": "National Library of Medicine (US), National Center for Biotechnology Information, ClinicalTrials.gov. U.S. National Institutes of Health, https://clinicaltrials.gov/ (2025)", "attributionShort": "NIH", "urlMain": "https://clinicaltrials.gov/about-site/trends-charts", "urlDownload": "https://clinicaltrials.gov/data-api/api", "dateAccessed": "2025-07-28", "datePublished": "2025", "license": {"url": "https://clinicaltrials.gov/about-site/terms-conditions", "name": "ClinicalTrials.gov Terms and Conditions"}}]}