Sexual function and quality of life: endpoints and outcomes.

Quality of sexual functioning and quality of life (QOL) are implacably interwoven phenomena. Therefore, realistic clinical trials of the efficacy of potential therapeutic agents for sexual dysfunction must include endpoints that reflect both sexual functioning and QOL. A review of design parameters in clinical trials demonstrates that the selection of well-developed psychological outcomes measures to define these endpoints can be an important factor in improving the sensitivity of clinical trials. The inclusion of well-designed and validated outcomes measures increases sensitivity through reductions in measurement of error and the deflection of additional variance associated with within-subjects variability. A brief list of recommended outcomes measures for both sexual functioning and relevant QOL domains is included. The roster of measures is not intended to be comprehensive; however, the instruments cited all have been well-designed, conform to the requirements of clinical trials, and have demonstrated sensitivity to therapeutic effects in previous investigations.