linelists

Linelists, or line lists, are tabular records used primarily in epidemiology and public health to track individuals affected by an outbreak or disease cluster. In a linelist, each row represents a single case or unit, and each column holds a variable such as demographics, clinical features, timing, laboratory results, and exposure information. Linelists support rapid, granular data collection and are used for surveillance, case management, and contact tracing.

Common fields include case_id, age, sex, residence or location, date_of_onset, date_of_report, date_of_specimen, disease or syndrome, symptoms, severity, hospitalization status, outcome, laboratory_result, test_date, exposure_history, travel_history, and known contacts. Linelists can also capture data quality indicators and data source notes.

Data are assembled from multiple sources, including field investigations, hospital and laboratory reports, and surveillance systems. Data quality concerns include missing values, inconsistent coding, duplicate records, reporting delays, and geographic misclassification. Standardizing variable definitions and using data dictionaries improves comparability. Privacy considerations emphasize de-identification, data minimization, access controls, and ethical approvals when sharing information.

Linelists are used to describe outbreak dynamics, crisis response, and resource allocation, and to support analyses such as time-to-event estimates and transmission clustering. They are distinct from aggregated statistics and are often a precursor to epidemiological curves and more formal analyses. Limitations include potential biases, incomplete coverage, and the absence of a population denominator.