Accessing data from external centralized sources to enhance analysis of a completed clinical trial

Mazen Abdellatif, Domenic J. Reda, David Williams, William C. Cushman, Barry J. Materson

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


After the data collection phase of a clinical trial has been completed, new hypotheses may surface which require additional data before they can be tested. In the Veterans Affairs Cooperative Study on Single Drug Therapy of Hypertension, we investigated the relationship between location of the participating center, race and ability to control blood pressure. The analysis indicated poorer blood pressure control among sites located in the 'stroke belt' (southeastern United States), especially among African- Americans. We sought to determine whether the effect was attributable to socioeconomic patterns; however, income data were not collected as part of the original study. Therefore, we accessed centralized data bases to obtain zipcode-level income information for the randomized study patients. This approach yielded estimates of income data for 94.3% of the patients and compared favorably to data acquisition rates for variables which were collected prospectively in the study.

Original languageEnglish (US)
Pages (from-to)183-188
Number of pages6
JournalJournal of Medical Systems
Issue number3
StatePublished - Nov 17 1999


  • Centralized data bases
  • Clinical trials
  • Data acquisition rates
  • Data collection
  • Hypertension
  • National VAMC Outpatient Care File
  • Socioeconomic patterns
  • Stroke belt

ASJC Scopus subject areas

  • Biophysics


Dive into the research topics of 'Accessing data from external centralized sources to enhance analysis of a completed clinical trial'. Together they form a unique fingerprint.

Cite this