The last few decades have seen a marked increase in mean life expectancy in Central Europe. This has made elderly people and their quality of life a matter of ever-increasing medical concern. Available data from the United States and Scandinavia relating to erectile dysfunction (ED) do not enable us to draw valid conclusions about the current situation in Germany. The aim of the present study was to evaluate the epidemiology of male sexuality in Germany, and the proportion of men who need medical treatment because of increased suffering from this.A newly developed and validated questionnaire on male erectile dysfunction was mailed to a representative population sample of 8000 men, 30±80 y of age in the Cologne urban district.The response included 4489 evaluable replies (56.1%). The response rates in different age groups ranged from 49.2% to 68.4%. Regular sexual activity was reported by 96.0% (youngest age group) to 71.3% (oldest group). There were 31.5%±44% of responders who were dissatis®ed with their current sex life. The prevalence of ED was 19.2%, with a steep age-related increase (2.3± 53.4%) and a high co-morbidity of ED with hypertension, diabetes, pelvic surgery and`lower urinary tract symptoms'. When treatment need was de®ned by co-occurence of ED and dissatisfaction with sex life, 6.9% men required treatment for ED. Oral treatment of ED was preferred by 73.8% of respondents. There were 46.2% respondents who were willing to contribute more than DM 50 (25 Euro) per month for ED treatment.We conclude that regular sexual activity is a normal ®nding in advanced age. ED is a frequent disorder, contributing to dissatisfaction with sex life in a considerable proportion of men. The high burden of ED is re¯ected in willingness to pay for treatment. ED is frequently associated with chronic diseases. Therefore adequate diagnostic workup is essential, to offer patients individually adapted treatment. General non-reimbursability of treatment for ED appears to be unacceptable.

A method for group sequential trials that is based on the inverse normal method for combining the results of the separate stages is proposed. Without exaggerating the Type I error rate, this method enables data-driven sample size reassessments during the course of the study. It uses the stopping boundaries of the classical group sequential tests. Furthermore, exact test procedures may be derived for a wide range of applications. The procedure is compared with the classical designs in terms of power and expected sample size.

'Multistage testing with adaptive designs' was the title of an article by Peter Bauer that appeared 1989 in the German journal Biometrie und Informatik in Medizin und Biologie. The journal does not exist anymore but the methodology found widespread interest in the scientific community over the past 25 years. The use of such multistage adaptive designs raised many controversial discussions from the beginning on, especially after the publication by Bauer and Köhne 1994 in Biometrics: Broad enthusiasm about potential applications of such designs faced critical positions regarding their statistical efficiency. Despite, or possibly because of, this controversy, the methodology and its areas of applications grew steadily over the years, with significant contributions from statisticians working in academia, industry and agencies around the world. In the meantime, such type of adaptive designs have become the subject of two major regulatory guidance documents in the US and Europe and the field is still evolving. Developments are particularly noteworthy in the most important applications of adaptive designs, including sample size reassessment, treatment selection procedures, and population enrichment designs. In this article, we summarize the developments over the past 25 years from different perspectives. We provide a historical overview of the early days, review the key methodological concepts and summarize regulatory and industry perspectives on such designs. Then, we illustrate the application of adaptive designs with three case studies, including unblinded sample size reassessment, adaptive treatment selection, and adaptive endpoint selection. We also discuss the availability of software for evaluating and performing such designs. We conclude with a critical review of how expectations from the beginning were fulfilled, and -if not -discuss potential reasons why this did not happen.

No abstract

It is the policy of the EC Respiratory Health Survey to indicate that the results presented are from a local analysis, and any final international comparison may use a different form of analysis.

Our meta-analysis provides evidence that preoperative statin therapy exerts substantial clinical benefit on early postoperative adverse outcomes in cardiac surgery patients, but underscores the need for RCT trials.

In a recent paper, BROWNE (1995) investigated the use of a pilot sample for sample size calculation.Monte Carlo simulations indicated that using a 100 -(1y ) per cent upper one-sided confidence limit on the population van' ance 02 leads to a sample size that guarantees the pIanned power with a probability of at least 1y. The purpose of this paper is to get further insight into the results of BROWNE by analytical considerations. Furthermore, the expected power is investigated when applying the strategy and recommendations for the choice of the pilot sample size are given.

Objective: To identify parameters which predict individual growth response to recombinant human GH (rhGH) therapy and to combine these parameters in a prediction model. Design: Fifty-eight prepubertal patients with GH deficiency (17 females) participated in this prospective multicenter trial with 1 year of follow-up. Methods: Auxological measurements, parameters of GH status and markers of bone metabolism were measured at baseline and at 1, 3 and 6 months after the start of rhGH treatment. Correlations with height velocity during the first 12 months of treatment HV 12 were calculated. Prediction models were derived by multiple regression analysis. Results: The model which best predicted HV 12 combined the following parameters: pretreatment bone age retardation as a fraction of chronological age, pretreatment serum levels of IGF-I, urinary levels of deoxypyridinoline (a marker of bone resorption) after 1 month of treatment and height velocity after 3 months of treatment. This model explained 89% of the variation in HV 12 with a standard deviation of the residuals of 0.93 cm/year. Defining successful rhGH therapy as a doubling of pretreatment height velocity, the model had a specificity of 90% and a sensitivity of 100% in predicting therapeutic success. Conclusions: This model is an accurate and practicable tool to predict growth response in GH-deficient children. It may help to optimize rhGH therapy by individual dose adjustment and contribute to improved overall outcomes.European Journal of Endocrinology 144 13±20