Data quality strategies in cohort studies: lessons from a study on delirium in nursing home elders.

Data quality has a direct impact on reliability and validity; however, procedures are usually briefly summarized in the Methods section of reports. Sustaining data quality and integrity over time can pose serious challenges, prompting the development of a data quality program based on Donabedian's quality framework. Although many are familiar with the structure, process, and outcome components in health care quality, their application to a research project may be unfamiliar. This article summarizes the data quality program for a cohort study of nursing home elders with delirium by providing an "insider's view" of procedures and protocols followed for several years.