Study data were collected and managed using REDCap electronic data capture tools hosted in the Biostatistics Division of Washington University School of Medicine. REDCap (Research Electronic Data Capture) is a secure, web-based application designed to support data capture for research studies, providing: 1) an intuitive interface for validated data entry; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for importing data from external sources.

Data Dictionary 

  • CSV format
  • The Data Dictionary is a specifically formatted spreadsheet in CSV format containing the metadata used to construct data collection instruments and fields.

Codebook of Variables 

  • PDF format
  • The Codebook includes variable names, variable descriptions, and field attributes (field type, validation, choices, calculations, etc.). It contains all the information given in the data dictionary, but is more user friendly and easier to read and interpret.

Data File**

**You will be prompted to submit your name, email and institutional affiliation prior to downloading. While we do not wish to restrict access to this dataset, we are curious to know who is taking interest. This information will not be used for any purpose other than tracking, but we may wish to contact you in the future to follow up. Thank you for your interest in the project data!