Labelling 'unexpected' deaths on a neurology service

We wrote a list of descriptive phrases to dichotomize admissions to a neurology service by a priori perceptions of risk of death within 30 days as "higher than average" versus "lower than average." In 500 consecutive admissions, the higher-risk list carried a 17-fold relative risk of death for the 20% of admissions so classified. The list is a valid and informative predictor of 30-day outcome that supports a classification of deaths as "expected" or "unexpected."