Data Bases and Analysis Tools

Data Bases

Data base files include actual data plus the dictionaries (bounds files) and painted screen versions for data entry. The CCCT has data bases for all the studies. Data in the files include:

• Randomization record with eligibility and other information
• Baseline interview form, usually with blood pressures and other pertinent data
• Baseline lab and ECG records
• Follow-up visit interview forms, usually with blood pressures and other pertinent data (quarterly and extending for up to seven years)
• Follow-up labs (semi-annual or annual)
• Follow-up ECG's (biannually or less usually)
• Event data (hospitalizations and deaths)
• Event ECG's
• Other data for specific studies: 24-hour holter analysis in BHAT; detailed dietary logs in CARE; ancillary HCFA and Veterans Administration data in ALLHAT; etc.

New studies use Microsoft SQL Server data bases.

After completion of a study, the data is disseminated to the sponsor. To do this the CCCT often prepares an exportable version of the entire master file; in other cases, a subfile is extracted that the sponsor uses for submission to the Federal Drug Administration.

Customized Programs

The CCCT has thousands of programs and routines, mostly Fortran, which were written to manage the ISAM data bases, do data entry (commercial package enhancements), generate the randomizations, monitor and edit the data, and provide statistical data analyses.

SAS and STATA

SAS and STATA are used to perform statistical data analyses. This includes producing tabular data, Cox-regressions, life tables, t-tests, chi-square values, and graphs.

Crystal Reports

Crystal Reports is a reporting tool used to develop and design comprehensive reports, draw information from data bases, make tables and charts, and integrate with Visual Studio.NET applications. Drill-down reports and subreports are also set up using this tool.