Introduction: No validated questionnaires to assess the subjective aspects of premature ejaculation (PE) are currently in use. Clinical trials have generally only considered time, measured by ejaculatory latency, as an indicator of efficacy, but ejaculatory control, sexual satisfaction, and distress are important aspects of PE, which impact both the patient and his partner. The objective of this study was to develop and validate a new questionnaire to measure the overall experience of PE.
Methods: The questionnaire was developed using four stages: item pool development, initial psychometric analyses, patient interviews, and final psychometric analyses.
Results: An item pool of 17 was generated and reduced to 10 items through the initial psychometric analyses. Patient interviews did not require addition of further items and resulted in only minor modifications to item wording for clarity. Final psychometric analyses of the 10-item measure confirmed a three-factor solution: sexual satisfaction, control, and distress. Reliability was good, both internal consistency and test-retest reliability. Convergent validity using intravaginal ejaculatory latency time was excellent: control domain (0.75), sexual satisfaction domain (0.60), and distress domain (0.68). Known-groups validity was very good, all domain mean scores being statistically significantly worse in men with PE compared with the men reporting no PE problems.
Conclusion: The Index of Premature Ejaculation is a reliable and valid questionnaire for the assessment of control over ejaculation, satisfaction with sex life, and distress in men with PE. This tool has the potential to add value to interpretations of improvements in ejaculation latency resulting from new treatments of PE.