Using observer methods in ems research

Emergency medical cares delivered under conditions that make assessment of certain performance aspects difficult by means other than direct observation. Concern that then use of observers may affect performance of those observed is reasonable, but on the evidence should not be paramount. Methodological issues in implementing an observer study include observer selection, training, deployment, monitoring, and data recording. The essential task of observer selection and training is to provide observers who can observe and record emergency medical care without self-involvement in that care. Because EMS data collected by observers is expensive, a tradeoff must be made between the representativness of the data and the efficiency of collection. It I s necessary to systematically monitor observers, particularly for problems of observer co-option, observer drift, and the effects of boredom. Validity and reliability issues and ethical and legal questions are also discussed.