Age-Specific Clinical Features of Erectile Dysfunction

Sexual health can be considered as a mirror of general health and, in turn, general health is a prerequisite for sexual heath. The aim of this study was to compare the different clinical features of erectile dysfunction (ED) in young and elderly males. From June 2011 to December 2011, 224 patients were included and divided into two groups. Elderly ED group consisted of 120 patients with ED and all were 61 - 90 years old, and young ED group consisted of 104 patients with ED and all were 21 - 45 years old. Questionnaires, physical examination, blood sample test, ultrasound monitor, time of achieving erection (TAE), intra-vaginal ejaculation latency time (IELT), ECG and penis-brachial blood pressure index (PBI) were investigated. There were significant differences between the two groups, regarding the top three complications, the body mass index (BMI), International Index of Erectile Function-5 (IIEF-5) scores, Self-rating Depression Scale (SDS) total scores, TAE, IELT and PBI. We concluded that clinical features of ED were age-specific, which will be helpful for treatment strategies and evaluation of the treatment efficacy.

Treatment of Unexplained Infertility by Acupuncture in Natural and Control Ovarian Hyperstimulation Cycles: A Prospective Analysis

Acupuncture is an important method of treatment in Chinese medicine. The objective of this study was to evaluate the efficacy of acupuncture as an adjuvant treatment for unexplained infertility. Here we conducted a prospective study, with data consisting of acupuncture group (38 cases) and control group (42 cases). Infertility evaluation workup consisted of semen analysis, ovulation assessment, hysterosalpingogram (HSG) and blood analysis. The patients in acupuncture group received 3 acupuncture sessions, and each at seven acupuncture points (EX-CA1, CV4, CV6, SP10, ST36, SP6, and KI3). The session started 12 days before menstruation and continued for 10 days. The patients in control group did not receive acupuncture. All patients tried 1 - 3 natural cycles 3 months after HSG test, if not pregnant, underwent 1 - 3 cycles of control ovarian hyperstimulation (COH) and timed intercourse. Pregnancy was evaluated by measurement of blood β human chorionic gonadotrophin (β-hCG) and subsequent trans-vaginal ultrasound. No significant difference of clinical pregnancy rate was found between the acupuncture group and the control group, however, numbers of COH cycles were significantly less and more pregnancies occurred in natural cycle in the acupuncture group. We concluded that acupuncture can be used as an adjuvant treatment for unexplained infertility. Although acupuncture did not increase the cumulative pregnancy rate, it decreased the number of COH cycles and more patients got pregnant in natural cycles after receiving acupuncture.

ANALYSIS OF THE IMPACT OF SAMPLE SIZE, ATTRIBUTE VARIANCE AND WITHIN-SAMPLE CHOICE DISTRIBUTION ON THE ESTIMATION ACCURACY OF MULTINOMIAL LOGIT MODELS USING SIMULATED DATA

Literature review indicates that sample size, attribute variance and within-sample choice distribution of alternatives are important considerations in the estimation of multinomial logit （MNL） models, but their impacts on the estimation accuracy have not been systematically studied. Therefore, the objective of this paper is to provide an empirical examination to the above issues through a set of simulated discrete choice preference and rank ordered preference datasets. In this paper, the utility coefficients, alternative specific constants （ASCs）, and the mean and standard deviation of the four attributes for a set of seven hypothetical alternatives are specified as a priori. Then, synthetic datasets, with varying sample size, attribute variance and within-sample choice distribution are simulated. Based on these datasets, the utility coefficients and ASCs of the specified MNLs are re-estimated and compared with the original values specified as the priori. It is found that （1） the estimation accuracy of utility parameters increases as the sample size increases; （2） the utility coefficients can be re-estimated with reasonable accuracy, but the estimates of the ASCs are confronted with much larger errors; （3） as the variances of the alternative attributes increase, the estimation accuracy improves significantly; and （4） as the distribution of chosen choices becomes more balanced across alternatives within sample datasets, the hit-ratio decreases. The results indicate that （a） under a similar setting presented in this paper, a large sample consisting of a few thousand observations （3000 - 4000） may be needed in order to provide reasonable estimates for utility coefficients, particularly for ASCs; （b） a larger, but realistic attribute space is preferred in the stated preference survey design; and （c） choice datasets with unbalanced ＂chosen＂ choice frequency distribution is preferred, in order to better capture the elasticity between the ＂perceived utility＂ associated with alternative＇s attributes.