Research and Scholarly Activity Series -- 10/26/21 -- Live Biostatistics consultation with Janice Weinberg, Professor of Biostatistics, BU School of Public Health with Dr. Naina Limbekar, Assistant Professor of Neurology, BU School of Medicine, talking about a retrospective observational study design and statistical considerations in a study of treated and untreated obstructive sleep apnea impact on COVID-19 outcomes collected from the electronic health record. We discussed how a very well-defined study question, knowing your exposures and outcome variables, and thinking in advance about how your data needs to be cleaned and managed before being analyzed are keys to ensuring success and avoiding surprises.