Clinicaltrials Find Eligible
clinicaltrials_find_eligibleMatch patient demographics and conditions to eligible recruiting clinical trials. Provide age, sex, conditions, and location to find studies with matching eligibility criteria, contact information, and recruiting locations. Results are re-ranked so studies whose own condition matches a requested condition surface above tangential matches from ClinicalTrials.gov's fuzzy condition search. Each candidate returns only the sites matching the requested location (capped by locationLimit), not the study's full registered site list — a large trial can register hundreds of sites worldwide. When none of a candidate's matched sites is recruiting, one recruiting site is added so an enrollable site is never hidden behind a closer closed one: the one nearest the matched sites by their published coordinates, in the requested country whenever a site there recruits, carrying distanceMi, or the first in match order when coordinates are missing. Fetch a study's complete record with clinicaltrials_get_study_record.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| age | Yes | Patient age in years. | |
| sex | Yes | Patient's biological sex. Use 'ALL' to include studies regardless of sex restrictions. | |
| location | Yes | Patient location as `{ country (required), state?, city? }`. Country is required; state/city narrow the match. For radius-based geographic search, use clinicaltrials_search_studies with geoFilter. | |
| conditions | Yes | Medical conditions or diagnoses, e.g. ["Type 2 Diabetes", "Hypertension"]. Each entry is matched as a condition (multi-word entries match as a phrase); multiple entries are combined with OR, so studies for any listed condition qualify. Returned studies are re-ranked so those whose own condition list names a requested condition rank above tangential matches the upstream fuzzy search pulls in via the MeSH umbrella. | |
| maxResults | No | Maximum results to return. | |
| locationLimit | No | Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, one recruiting site is added on top of it (the nearest to any matched site, measured before this cap, when coordinates allow — in the requested country whenever a site there recruits), so a candidate can carry one site more than this. Raise it to see more nearby sites, or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites. | |
| recruitingOnly | No | Only include actively recruiting studies. | |
| healthyVolunteer | No | Whether the patient is a healthy volunteer. When true, only studies accepting healthy volunteers are queried. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| error | No | Present when the call failed. Absent on success. | |
| funnel | No | Match counts at each filter stage. Shows where the funnel collapsed — e.g., conditionMatched=298 but demographicsMatched=2 means age/sex/status are the constraint. | |
| notice | No | Recovery guidance when no studies matched — identifies which filter stage collapsed and suggests how to broaden. Absent when results are returned. | |
| studies | No | Matching studies with eligibility and location fields. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, one added recruiting site — not the study's full registered site list. The added site is the one nearest any matched site by published coordinates, taken from the requested country whenever a site there recruits, and carries distanceMi (miles to that nearest matched site); when the matched or recruiting sites publish no coordinates it is the first in match order and carries no distanceMi. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added (the key keeps its name in the match-order fallback). Fetch a study's complete record and site list with clinicaltrials_get_study_record. | |
| totalCount | No | Total matching studies from the API. | |
| searchCriteria | No | Normalized search criteria applied to this eligibility query, including the exact upstream query strings needed to reproduce the full match set via clinicaltrials_search_studies (replay with includeUnknownEnrollment=true, which find_eligible always sets). |