DEVELOPING AN OBJECTIVE MEASURE OF PARTICIPANT PERFORMANCE IN LONG-DURATION BED REST STUDIES

INTRODUCTION: Head-Down Bed Rest (HDBR) methodology has been used for over 20 years to study the effects of microgravity (Traon, Heer, Narici, Rittweger, & Vernikos, 2007). Although used primarily as an analog for studying physiological effects of spaceflight, HDBR produces psychological effects as well. Compared to the pre- and post- phases of HDBR, participants have exhibited increased levels of depression (Ishizaki et al., 2002; Styf, Hutchinson, Carlsson, & Hargens, 2001) and stress (Chouker et al., 2001) during the head-down phase. Thus, selecting participants who are capable of performing under the psychologically demanding conditions of HDBR is essential. METHODS: Candidates for participation in a NASA HDBR study are screened by a licensed clinical psychologist for the presence of psychological disorders or traits that could interfere with their successful completion of the study, and for positive characteristics that make them well-qualified to participate in a HDBR study (Seaton, Bowie, & Sipes, 2009). To validate and further improve the selection process, a standardized measure of participant performance that could be used by multiple raters was needed. Behaviorally Anchored Rating Scales (BARS; Smith & Kendall, 1963) were developed through the use of the critical incident technique (CIT; Flanagan, 1954), along with traditional BARS development procedures, and the use of focus groups. These methodologies yielded 86 usable critical incidents, which were used as anchors for the scales. DISCUSSION: The scale developed, the HDBR-BARS, is the first objective outcome measure designed to assess the performance of NASA HDBR participants. Current and future bed rest participants will be rated using the HDBR-BARS, and results of the analyses will help to validate and refine the selection process. In addition, the HDBR-BARS could serve as a model for the development of outcome measures for other spaceflight analogs.