Construct validity of the PROMIS® sexual function and satisfaction measures in patients with cancer

BACKGROUND: With data from a diverse sample of patients either in treatment for cancer or post-treatment for cancer, we examine inter-domain and cross-domain correlations among the core domains of the Patient-Reported Outcomes Measurement Information System Sexual Function and Satisfaction measures (PROMIS® SexFS) and the corresponding domains from conceptually-similar measures of sexual function, the International Index of Erectile Function and the Female Sexual Function Index. FINDINGS: Men (N=389) and women (N=430) were recruited from a tumor registry, oncology clinics, and an internet panel. The PROMIS SexFS, International Index of Erectile Function, and Female Sexual Function Index were used to collect participants' self-reported sexual function. The domains shared among the measures include desire/interest in sexual activity, lubrication and vaginal discomfort/pain (women), erectile function (men), orgasm, and satisfaction. We examined correlations among different domains within the same instrument (discriminant validity) and correlations among similar domains measured by different instruments (convergent validity). Correlations demonstrating discriminant validity ranged from 0.38 to 0.73 for men and 0.48 to 0.74 for women, while correlations demonstrating convergent validity ranged from 0.62 to 0.83 for men and 0.71 to 0.92 for women. As expected, correlations demonstrating convergent validity were higher than correlations demonstrating discriminant validity, with one exception (orgasm for men). CONCLUSIONS: Construct validity was supported by convergent and discriminant validity in a diverse sample of patients with cancer. For patients with cancer who may or may not have sexual dysfunction, the PROMIS SexFS measures provide a comprehensive assessment of key domains of sexual function and satisfaction.