# Quick Reference Guide - ClinicalTrials.gov MCP Server
Common query patterns and use cases for the ClinicalTrials.gov MCP Server.
## Basic Searches
### Search by Condition
```
Tool: search_clinical_trials
Parameters:
query_cond: "Depression"
page_size: 20
```
**Common conditions:**
- Depression
- Type 2 Diabetes
- Breast Cancer
- Alzheimer's Disease
- COVID-19
- Hypertension
- Asthma
- PTSD
- Schizophrenia
- Multiple Sclerosis
### Search by Intervention/Drug
```
Tool: search_clinical_trials
Parameters:
query_intr: "Pembrolizumab"
page_size: 20
```
**Common interventions:**
- Pembrolizumab
- Nivolumab
- Cognitive Behavioral Therapy
- Ketamine
- Insulin
- Metformin
- SSRI
- Radiotherapy
### Combined Condition + Intervention
```
Tool: search_clinical_trials
Parameters:
query_cond: "Melanoma"
query_intr: "Pembrolizumab"
page_size: 20
```
## Filtering by Status
### Find Recruiting Trials
```
Tool: search_clinical_trials
Parameters:
query_cond: "Anxiety"
filter_overallStatus: ["RECRUITING"]
```
### Valid Status Values:
- `RECRUITING` - Currently enrolling participants
- `NOT_YET_RECRUITING` - Not yet open for enrollment
- `ACTIVE_NOT_RECRUITING` - Ongoing but not enrolling
- `COMPLETED` - Study has concluded
- `SUSPENDED` - Temporarily paused
- `TERMINATED` - Stopped early
- `WITHDRAWN` - Withdrawn before enrollment
- `ENROLLING_BY_INVITATION` - Only enrolling invited participants
### Multiple Statuses
```
Tool: search_clinical_trials
Parameters:
query_cond: "Depression"
filter_overallStatus: ["RECRUITING", "NOT_YET_RECRUITING"]
```
## Location-Based Searches
### Search by City/State
```
Tool: search_clinical_trials
Parameters:
query_locn: "Boston"
query_cond: "Cancer"
```
### Search by Institution
```
Tool: search_clinical_trials
Parameters:
query_locn: "Mayo Clinic"
```
### Geographic Radius Search
```
Tool: search_clinical_trials
Parameters:
query_cond: "Diabetes"
filter_geo: "distance(40.7128,-74.0060,50mi)"
```
Format: `distance(latitude,longitude,distance)`
- Distance can be in miles (mi) or kilometers (km)
- NYC coordinates: 40.7128, -74.0060
- LA coordinates: 34.0522, -118.2437
- Chicago coordinates: 41.8781, -87.6298
## Sponsor Searches
### Federal Agencies
```
Tool: search_clinical_trials
Parameters:
query_spons: "National Institute of Mental Health"
```
**Common federal sponsors:**
- National Institute of Mental Health (NIMH)
- National Cancer Institute (NCI)
- National Heart, Lung, and Blood Institute (NHLBI)
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- National Institute on Aging (NIA)
### Pharmaceutical Companies
```
Tool: search_clinical_trials
Parameters:
query_spons: "Pfizer"
```
### Academic Institutions
```
Tool: search_clinical_trials
Parameters:
query_lead: "Stanford University"
```
## Advanced Searches
### Phase-Specific Trials
```
Tool: search_clinical_trials
Parameters:
query_cond: "Alzheimer's Disease"
filter_advanced: "SEARCH[Study](AREA[Phase]PHASE3)"
```
### Recent Trials (Last 2 years)
```
Tool: search_clinical_trials
Parameters:
query_cond: "COVID-19"
filter_advanced: "SEARCH[Study](AREA[StartDate]RANGE[2023-01-01,MAX])"
```
### Large Trials (>500 participants)
```
Tool: search_clinical_trials
Parameters:
query_cond: "Cardiovascular Disease"
filter_advanced: "SEARCH[Study](AREA[EnrollmentCount]RANGE[500,MAX])"
```
## Pagination
### First Page
```
Tool: search_clinical_trials
Parameters:
query_cond: "Breast Cancer"
page_size: 50
count_total: true
```
### Next Page
Use the `nextPageToken` from the previous response:
```
Tool: search_clinical_trials
Parameters:
query_cond: "Breast Cancer"
page_size: 50
page_token: "abc123xyz..."
```
## Getting Study Details
### By NCT ID
```
Tool: get_clinical_trial
Parameters:
nct_id: "NCT04267848"
```
### Multiple Studies
Call the tool multiple times with different NCT IDs:
```
Tool: get_clinical_trial
Parameters:
nct_id: "NCT04267848"
Tool: get_clinical_trial
Parameters:
nct_id: "NCT03456789"
```
## Research Use Cases
### 1. Literature Review - Find All Trials for Condition
```
Tool: search_clinical_trials
Parameters:
query_cond: "Major Depressive Disorder"
page_size: 100
count_total: true
sort: ["LastUpdatePostDate:desc"]
```
### 2. Competitive Intelligence - Company's Trials
```
Tool: search_clinical_trials
Parameters:
query_spons: "Biogen"
filter_overallStatus: ["RECRUITING", "ACTIVE_NOT_RECRUITING"]
```
### 3. Site Feasibility - Local Recruiting Trials
```
Tool: search_clinical_trials
Parameters:
query_cond: "Rheumatoid Arthritis"
query_locn: "Philadelphia"
filter_overallStatus: ["RECRUITING"]
```
### 4. Patient Recruitment - Matching Criteria
```
# First, search broadly
Tool: search_clinical_trials
Parameters:
query_cond: "Type 2 Diabetes"
query_locn: "Seattle"
filter_overallStatus: ["RECRUITING"]
# Then get details for specific trials
Tool: get_clinical_trial
Parameters:
nct_id: "NCT[from search]"
```
### 5. Regulatory Intelligence - Recently Completed
```
Tool: search_clinical_trials
Parameters:
query_intr: "CAR-T"
filter_overallStatus: ["COMPLETED"]
sort: ["CompletionDate:desc"]
```
### 6. Market Research - Pipeline Analysis
```
Tool: search_clinical_trials
Parameters:
query_cond: "Alzheimer's Disease"
filter_overallStatus: ["RECRUITING", "ACTIVE_NOT_RECRUITING"]
sort: ["@relevance"]
page_size: 100
```
## Statistics
### Overall Trial Statistics
```
Tool: get_trial_statistics
Parameters: {}
```
### Status Distribution
```
Tool: get_trial_statistics
Parameters:
filter_overallStatus: ["RECRUITING"]
```
### Geographic Distribution
```
Tool: get_trial_statistics
Parameters:
filter_geo: "distance(40.7,-74,100mi)"
```
## Tips and Best Practices
### 1. Start Broad, Then Narrow
```
# Step 1: Broad search
query_cond: "Cancer"
# Step 2: Add specificity
query_cond: "Lung Cancer"
filter_overallStatus: ["RECRUITING"]
# Step 3: Add location
query_cond: "Lung Cancer"
filter_overallStatus: ["RECRUITING"]
query_locn: "California"
```
### 2. Use Alternative Terms
Try different terminology:
- "Depression" vs "Major Depressive Disorder" vs "MDD"
- "Heart Attack" vs "Myocardial Infarction" vs "MI"
- "Stroke" vs "Cerebrovascular Accident" vs "CVA"
### 3. Check Patient-Friendly Search
```
Tool: search_clinical_trials
Parameters:
query_patient: "heart disease"
```
### 4. Verify with Multiple Searches
Cross-reference results:
```
# Search 1: By condition
query_cond: "Parkinson's Disease"
# Search 2: By intervention
query_intr: "Levodopa"
# Search 3: By sponsor
query_spons: "Michael J Fox Foundation"
```
### 5. Use Page Tokens for Large Datasets
```
# Always set count_total on first request
count_total: true
page_size: 100
# Use returned page_token for subsequent requests
page_token: "[token from previous response]"
```
## Common Gotchas
1. **NCT IDs**: Must include "NCT" prefix (e.g., "NCT04267848", not "04267848")
2. **Status values**: Must be exact (e.g., "RECRUITING" not "recruiting")
3. **Geographic search**: Requires exact format `distance(lat,lon,distance)`
4. **Pagination**: Must use same search parameters when using page_token
5. **Timeout**: Default is 30 seconds - complex searches may timeout
6. **Result limits**: Maximum page_size is 1000
## Error Messages
### "No studies found"
- Try broader search terms
- Remove filters
- Check spelling
### "Invalid status value"
- Use exact status names from the list above
- Status values are case-sensitive
### "Invalid NCT ID"
- Must start with "NCT"
- Must be exactly 8 digits after NCT
- Example: NCT04267848
### "Geographic filter error"
- Check format: `distance(lat,lon,distance)`
- Latitude: -90 to 90
- Longitude: -180 to 180
- Distance must include unit (mi or km)
## Resources
- [ClinicalTrials.gov Search Tips](https://clinicaltrials.gov/search/about)
- [Study Record Structure](https://clinicaltrials.gov/data-api/about-api/study-data-structure)
- [Full API Documentation](https://clinicaltrials.gov/data-api/api)
