Defining outcome

The two Papers by Vogenthaler and colleagues, concerning long-term productivity and independent living outcomes of the brain-injured, are of considerable interest. Not only do they identify the features of late outcome in a large group of severely injured patients, but they also attempt to model the key factors which predict those outcomes. The Papers, while of interest in themselves (Who has a good outcome? Who does not fit a general trend? Is severity of injury important?), also serve as a succinct introduction to the problems and dilemmas facing anyone attempting to measure outcome after severe brain injury. The problems range from making an operational definition of outcome; to deciding on a study population; deciding on an appropriate follow-up; identifying appropriate and achievable methodologies; identifying important predictors; and judging the clinical significance and generalizability of the results.