Expressing observations from electronic medical record flowsheets in an i2b2 based clinical data repository to support research and quality improvement

Abstract

While nursing documentation in electronic medical record (EMR) flowsheets may represent the largest investment of clinician time with information systems, organizations lack tools to visualize and repurpose this data for research and quality improvement. Incorporating flowsheet documentation into a clinical data repository and methods to reduce the flowsheet ontology's redundancy are described. 411 million flowsheet observations, derived from an EMR predominantly used in inpatient, outpatient oncology, and emergency room settings, were incorporated into a repository using the i2b2 framework. The local flowsheet ontology contained 720 "templates" employing 5,379 groups (2,678 distinct), 37,836 measures (13,659 distinct) containing 226,666 choices for a total size of 270,641. Aggressive pruning and clustering resulted in 150 templates, 743 groups (615 distinct), 6,950 measures (4,066 distinct) with 22,497 choices, and size of 30,371. Making nursing data accessible within i2b2 provides a new perspective for contributing clinical organizations and heightens collaboration between the academic and clinical activities.

Figure 1:

Vital Signs Template of a Flowsheet within the Electronic Medical Record: a. denotes the template (includes vital signs, pain assessment, etc.), b. group (includes temp, temp source, etc), and c. an individual flowsheet measure (BP – blood pressure).

Figure 2.

Flowsheet data represented in i2b2 illustrating an “Airway” Template, “Tracheostomy Tube” Group, “Trach Site Appearance” Flowsheet Measure, and the Choices for the Measure (“Dry and Intact”, “Bloody”, etc.)

Figure 3.

Similarity of flowsheet measures within the Cancer Center’s Vital Signs Template (#920553), Vitals and Extended Vitals Groups (#9209769, #9209770) and the Obstetrics Maternal Vitals Template (#12001), Maternal Vitals Group (#12000).

Figure 4.

Cumulative frequency diagram for the 1000 most frequently documented flowsheet measures

Figure 5.

Portion of the clustering dendrogram at 0.5 similarity threshold illustrating group mergers of vital signs.

Figure 6:

Portion of the clustering dendrogram at 0.5 similarity threshold illustrating merger of pediatric templates.