CLARK v1 is a machine-learning classification software created by NC TraCS and CoVar Applied Technologies to enable computable phenotyping in unstructured data. CLARK’s user-friendly interface makes natural language processing (NLP) an accessible option for searching free-text clinical notes. This page includes user instructions and technical documentation for CLARK v1.
For instructions on CLARK v2, go here.
For a conceptual guide to CLARK including research applications and interpretation of results, go here.
Both CLARK v1 and v2 are free and available for download here.
Getting Started
System Requirements
Installation
CLARK: Basic Steps
Navigation
Loading and Saving Progress
Key Concepts
Clinical Notes
Formatting
Metadata
Free Text
Regular Expressions
Basic Regular Expressions
Section Break
Clinical Examples
Training Corpus
Loading the Training Corpus
Troubleshooting
Features
Algorithm Setup
Training Corpus
Regular Expressions Library
Active Regular Expressions
Sectioning
Notes
Patients and Notes
Note with Additional Markup
Using the Notes Viewer
Algorithm
Algorithm Steps-Training Corpus
Algorithm Steps-Evaluation Corpus
Machine Learning Classifiers
Cross-Validation
Explore
Distribution by Labels
Confidence
Filtered Records
Evaluation Corpus Results
Exporting Results
Sensitivity and Specificity
Technical Appendix
Cross-validation
Algorithms in detail
General Troubleshooting
CLARK runs best on Windows machines with 16 GB of RAM, and does not require special infrastructure to operate. Processing may take longer with 8GB of RAM.