Relationship between patient self-assessment of erectile dysfunction and the Sexual Health Inventory for Men

Background: The Sexual Health Inventory for Men (SHIM) has been shown to possess favorable statistical properties in diagnosing the presence and severity of erectile dysfunction (ED). However, the SHIM has not been compared with patient self-assessment of ED. Objective: This article describes an independent-validation study examining the correlation and agreement between the SHIM and patient self-assessment of ED with respect to the severity of ED at baseline and after treatment, and in terms of change from baseline. Methods: The study population consisted of 247 male outpatients with ED participating in a multicenter, double-blind, placebo-controlled, flexible-dose (25-100 mg/d) Phase IIIb clinical trial in which they were randomized equally to sildenafil citrate or placebo. Patients assessed their degree of ED as severe, moderate, minimal/mild, or no problem at baseline and after 12 weeks of treatment. They also responded to the 5 questions on the SHIM, after which their degree of ED was calculated based on the SHIM total score. Results: In general, the SHIM and the single-item self-assessment question produced similar descriptive profiles of the severity of ED. Kendall tau -b correlations were 0.66 (95% Cl, 0.58-0.74) at baseline, 0.86 (95% Cl, 0.82-0.90) after treatment, and 0.72 (95% Cl, 0.67-0.77) for change from baseline. Agreement between instruments, measured by the weighted kappa statistic, mirrored the correlations at baseline and after treatment. As expected, both measures correlated moderately with improvement in erections and treatment satisfaction of both patient and partner. Conclusion: The moderate-to-high correlation and agreement between the SHIM and patient self-assessment of ED validate the SHIM for use in the diagnostic classification of ED severity.