Related Experiment Video
Updated: Jan 28, 2026

Enhanced Reduced Representation Bisulfite Sequencing for Assessment of DNA Methylation at Base Pair Resolution
Published on: February 24, 2015
Enhancing the Representational Power of i2b2 through Referent Tracking
Jonathan C Blaisure1,2, Werner M Ceusters1,2
1Institute for Healthcare Informatics, University at Buffalo, Buffalo, New York, USA.
This study shows how the Informatics for Integrating Biology and the Bedside (i2b2) platform can identify patient cohorts based on disagreements in diagnostic assertions. This advances clinical data analysis by revealing hidden ambiguities in patient records.
Area of Science:
- Biomedical Informatics
- Clinical Data Management
- Health Data Analytics
Background:
- The Informatics for Integrating Biology and the Bedside (i2b2) platform effectively identifies patient cohorts using demographic, phenotypic, and genetic data.
- A limitation of current i2b2 applications is the inability to search based on characteristics of clinical assertions (e.g., diagnoses) themselves, rather than just the conditions observed.
Purpose of the Study:
- To explore the feasibility of using i2b2's modifier system to represent relationships between observations and their referents.
- To enable cohort identification based on disagreements among healthcare providers regarding patient diagnoses.
Main Methods:
- Utilized i2b2's modifier system to explicitly represent relationships between clinical observations and their referents (explicit or implied).
- Stored unique instance identifiers for observations and referents within i2b2's fact table.
- Leveraged i2b2's base functionality and implementation specifications.
Main Results:
- Demonstrated that i2b2's modifier system can represent complex relationships between observations and referents.
- Successfully stored unique identifiers for observations and referents, facilitating detailed data analysis.
- The proposed approach makes explicit previously undetected ambiguities and confusions in clinical assertions.
Conclusions:
- The i2b2 modifier system can be extended to capture nuanced information about clinical assertions, including provider disagreements.
- This method enhances the ability to identify specific patient cohorts by analyzing the characteristics of diagnostic assertions.
- The approach improves the transparency of clinical data by revealing underlying ambiguities.
Related Concept Videos
State Space Representation
Consider an RLC circuit, a...
Control Volume and System Representations
The control volume approach considers a stationary region in space through which fluid flows. This region is bounded by a control surface. For instance, in the case of water...
Graphical Representation of Inequalities
Vector Representation of Complex Numbers
Consider a function defined as the product of the complex factors in the numerator divided by the product of the complex factors in the...
Graphical and Analytic Representation of Sinusoids
The first step is measuring the peak-to-peak value, which is twice the amplitude of the sinusoid. This provides information about the maximum voltage swing of the waveform.
Secondly, the period and angular frequency are determined. The period is the time taken for one complete cycle of the waveform, while...
Inertial Frames of Reference

