The development of a multidimensional quality of life protocol to be used in a clinical trial of an LVAS was presented. The complexity of the new LVAS technology being evaluated added a unique dimension for HQL assessment. The rationale and procedures used in developing this protocol were described. Although we have elucidated the development of a protocol for a specific clinical trial, the principles and procedures employed are widely applicable. To summarize, these procedures are as follows: 1. Determine what quality of life domains are important to measure. This decision should be based upon the domains expected to be affected by treatment, those expected to change as a result of the natural course of the disease or condition, and those that may be affected by changes in the primary domains. 2. Once the domains are selected, identify specific measures for these domains. Where possible, the measures chosen should be standardized, well validated, and appropriate to the study population. Instrument length and mode of administration are additional considerations. 3. Consider any unique aspects of the study population or intervention and develop specific questions to address them. 4. Identify and measure important variables that may moderate or influence quality of life. 5. Test the protocol on an appropriate population for length, flow, and ease of administration. Copies of the complete HQL protocol are available by writing to: Dr. Nancy Avis, New England Research Institute, 9 Galen Street, Watertown, MA 02172.