User surveys are often used to estimate usage of online systems. We asked medical student to estimate their weekly use of KnowledgeMap, an online medical education system, during the previous semester. The information was validated against server log files. The average number of log-on days was significantly different across four categories of self-reported use. Self-reported frequency scales may be used to correctly segregate users into discrete ordinal usage groups.

Many authors have reported on the use of the Unified Medical Language System (UMLS) to match concepts in free text. Unmatched search strings may be due to misspellings, concepts not in the UMLS, or searches for words not expected to be in the UMLS (e.g., names of people or places). We mapped search strings from a full-text, concept-based curriculum database to UMLSconcepts and performed a failure analysis. The majority of unmatched text strings were medically related (71.7%).

A computerized tool designed to facilitate physician sign-out has been in use at Vanderbilt University Hospital and Children's Hospital for close to a decade. The authors produced descriptive statistics of sign-out tool use by hospital unit, user's professional role, and time of day. Results showed anticipated use by resident physicians and nurse practitioners to generate and print notes, as well as unanticipated use by nurses, case managers, and medical receptionists/care partners to print providers' notes.

Clinical documentation is often expressed in natural language text, yet providers often use common organizations that segment these notes in sections, such as history of present illness or physical examination. We developed a hierarchical section header terminology, supporting mappings to LOINC and other vocabularies; it contained 1109 concepts and 4332 synonyms. Physicians evaluated it compared to LOINC and the Evaluation and Management billing schema using a randomly selected corpus of history and physical notes.

Graduate medical students must demonstrate competency in clinical skills. Current tracking methods rely either on manual efforts or on simple electronic entry to record clinical experience. We evaluated automated methods to locate 10 institution-defined core clinical problems from three medical students' clinical notes (n=290). Each note was processed with section header identification algorithms and the KnowledgeMap concept identifier to locate Unified Medical Language System (UMLS) concepts.

Clinical notes, typically written in natural language, often contain substructure that divides them into sections, such as "History of Present Illness" or "Family Medical History." The authors designed and evaluated an algorithm ("SecTag") to identify both labeled and unlabeled (implied) note section headers in "history and physical examination" documents ("H&P notes").

Medication information is one of the most important types of clinical data in electronic medical records. It is critical for healthcare safety and quality, as well as for clinical research that uses electronic medical record data. However, medication data are often recorded in clinical notes as free-text. As such, they are not accessible to other computerized applications that rely on coded data. We describe a new natural language processing system (MedEx), which extracts medication information from clinical notes. MedEx was initially developed using discharge summaries.

Patients with hospital-acquired acute kidney injury (AKI) are at risk for increased mortality and further medical complications. Evaluating these patients with a prediction tool easily implemented within an electronic health record (EHR) would identify high-risk patients prior to the development of AKI and could prevent iatrogenically induced episodes of AKI and improve clinical management.

De-identified clinical data in standardized form (eg, diagnosis codes), derived from electronic medical records, are increasingly combined with research data (eg, DNA sequences) and disseminated to enable scientific investigations. This study examines whether released data can be linked with identified clinical records that are accessible via various resources to jeopardize patients' anonymity, and the ability of popular privacy protection methodologies to prevent such an attack.

We describe a two-stage analytical approach for characterizing morbidity profile dissimilarity among patient cohorts using electronic medical records. We capture morbidities using the International Statistical Classification of Diseases and Related Health Problems (ICD-9) codes. In the first stage of the approach separate logistic regression analyses for ICD-9 sections (e.g., "hypertensive disease" or "appendicitis") are conducted, and the odds ratios that describe adjusted differences in prevalence between two cohorts are displayed graphically.