Assessment of health-related quality of life in acute in-patient settings: use of the BASES instrument in children undergoing bone marrow transplantation.

The Behavioral, Affective and Somatic Experiences Scale (BASES) represents a set of tools for assessing aspects of health-related quality of life (HRQL) in patients undergoing active, intensive therapy. Separate versions have been developed for parent, nurse and patient reports. The scales were constructed to be sensitive to change and appropriate for repeated measures in longitudinal designs. We report preliminary results with these measures from a sample of 105 children undergoing bone marrow transplantation (BMT). Adequate reliability of the instruments is documented through measures of both internal consistency and cross-informant consistency. Several analyses provide evidence of the clinical validity of the measures. Repeated-measures ANOVAs indicated reliable patterns of change over time, with trajectories that conformed to a priori predictions. Discriminative validity was demonstrated through detection of significant differences in the predicted direction between patients undergoing allogeneic and autologous BMT. Additional evidence for validity comes from the very similar symptom trajectories in parent, nurse and patient reports. Differences between the BASES and other measures of HRQL are identified and alternative uses of the instruments are discussed.