CHRONOMERGE: An Application for the Merging and Display of Multiple Time-Stamped Data Streams

Abstract

CHRONOMERGE is a database application that facilitates merging and display of multiple time-stamped data streams. Each stream is a table containing time-stamped values of one or more parameters (such as a panel of laboratory tests) for multiple patients, and is typically created by querying a clinical data respiratory. The data within a single stream therefore represent a pool of multiple time series. The merge operation is complex because of the numerous options to be considered, such as the granularity of the time interval for merge, and the choice of statistical aggregates. CHRONOMERGE combines multiple streams into a single stream based on patient and time, or time alone (if aggregates are to be computed across patients). It allows specification of various options through a graphical user interface and generates appropriate SQL code (or invokes procedural routines) to perform the merge. The resultant stream, or subsets of it, can then be displayed graphically. CHRONOMERGE is intended to facilitate the analysis of time-stamped data that have been extracted from repositories when standard tools (such as the time-series modules of statistics packages) are inadequate.