Clinical application of prognostic factors for patients with organic causes of erectile dysfunction on 100 mg of sildenafil citrate

Abstract

There are still no clinical predictive factors to determine the response rate of erectile dysfunction (ED) patients to sildenefil citrate. The aim of the present study is to evaluate and stratify the risk factors and attempted to determine the prognostic factors in clinical practice to predict the response rate. This is important in improving cost effectiveness and avoiding side-effects. This is an open label prospective study including patients attending the andrology clinic in Tan Tock Seng Hospital, Singapore, over 2 years. The patients were evaluated and investigated for possible underlying causes and ED severity was assessed by five-items of the International Index of Erectile Function questionnaire (IIEF-5), together with the duration, degree and rigidity of erection. Psychogenic causes were excluded with a minimal follow up of 6 months. All patients were placed on 100 mg of sildenafil citrate and were reassessed at the end of 6 months. Logistic regression with univariate and multivariate was used as the method of statistical analysis. A total of 232 patients were in the cohort. The overall response rate was 43%, with the best response rate in veno-occlusive cases and the worst responses from neurogenic causes. Age, smoking, diabetes mellitus, hypertension, hyperlipidemia, pretreatment IIEF-5 score, interval to achieve erection and duration of erection were significant in univariate analysis, but only age, smoking and IIEF-5 score were significant in multivariate analysis. With a combination of these factors, a table was formed to determine the possible response rate in clinical practice. This will assist physicians in selecting patients with potentially favorable responses and avoid side-effects and an unnecessary wastage of time and cost. Possible factors could be determined and used clinically to predict the response rate to sildenafil citrate.