Establishment and Implementation of Standardized Sleep Laboratory Data Collection and Scoring Procedures

ABSTRACT To standardize data collection and processing procedures, three Veterans Administration sleep laboratories established standard procedures “on paper,” implemented them in a study, and assessed scoring agreement for sleep EEG‐EOG recordings. The first phase of the study resulted in a detailed written description of all basic procedures. For the second, each laboratory evaluated 6 mentally and physically healthy males on three consecutive nights. Overall scoring agreement was about 90%. It was at least 89% between pairs of laboratories for stage 0, 59% for stage 1, 95% for stage 1 REM, 92% for stage 2, and 80% for stages 3+4. Values for standard sleep EEG‐EOG parameters were generally similar among scoring laboratories, and interlaboratory scoring agreement compared favorably with one measure of intralaboratory agreement. The low agreement for stage 1 is attributable to the infrequent and sporadic occurrence of stage 1 and is considered to be trivial. That for stages 3+4 is more critical and is probably related to the subjective process involved in scoring these stages. These data indicated that these techniques produced a high degree of interlaboratory standardization, and consequently, concurrence in sleep stage scoring.