RESUMEN
Large-scale, multisite data sets offer the potential for exploring the public health benefits of biomedical interventions. Data harmonization is an emerging strategy to increase the comparability of research data collected across independent studies, enabling research questions to be addressed beyond the capacity of any individual study. The National Institute on Drug Abuse recently implemented this novel strategy to prospectively collect and harmonize data across 22 independent research studies developing and empirically testing interventions to effectively deliver an HIV continuum of care to diverse drug-abusing populations. We describe this data collection and harmonization effort, collectively known as the Seek, Test, Treat, and Retain Data Collection and Harmonization Initiative, which can serve as a model applicable to other research endeavors.