POTENCY - THE VALIDATION OF INFORMATION FROM A SELF-ADMINISTERED QUESTIONNAIRE USING OBJECTIVE MEASUREMENTS OF NIGHTTIME ERECTIONS AND TEST-RETEST RELIABILITY

Objective To assess the validity and reliability of a questionnaire as sessing 'physiological potency', Patients and methods The study compri sed 89 patients with prostate cancer and 43 men without: the latter we re attending a consultation clinic because of problems with erection, All men answered three questions assessing erectile rigidity during se xual activity, morning and spontaneous erections, In the questionnaire , 'potency' was defined as erectile rigidity 'sufficient for intercour se most of the time' or better. 'Potency' in one or more of the three aspects of erection was defined as 'physiological potency', The patien ts with prostate cancer answered the questionnaire twice with a 3-week interval, The men attending the consultation clinic underwent two nig hts of erectile monitoring (using the RigiScan device) and the minimum criterion for RigiScan potency was defined as 55% rigidity at both ti p and base. Results The test-retest assessment showed 93% conformity i n the questionnaire diagnosis of 'physiological potency/impotence' bet ween the tests. The sensitivity and specificity of the questionnaire a ssessment compared with the RigiScan method were 40% and 100%, respect ively, when the question assessing sexually stimulated erectile rigidi ty was used alone, Using 'physiological potency', the sensitivity incr eased to about 60% without jeopardizing the specificity, and when men reporting depression were excluded from the analysis, the sensitivity increased to about 80%, Conclusions The test-retest reliability of the questionnaire was satisfactory, Using questions in a self-administere d questionnaire, 'physiological impotence' can be diagnosed with compl ete and 'physiological potency' with 60-80% sensitivity, The sensitivi ty of the self-assessment for 'potency' depended on the number of ques tions asked and the proportion of men reporting depression.