Study Design in Neurosurgical Research: Considerations for Observational and Experimental Cohort Studies.

There is inadequate neurosurgical literature discussing appropriate clinical study design. Here, we explore considerations for 2 fundamental study designs of epidemiology: experimental and observational cohort studies, through examples of theoretical yet realistic neurosurgical research questions. By examining 2 common neurosurgical procedures-namely, subdural drains for evacuation of chronic subdural hematoma, and the utility of navigation for placing external ventricular drains-we characterize the framework of cohort study models for clinical research applications.