BACKGROUND Only four out of 31 completed randomized controlled trials (RCTs) of HIV prevention strategies against sexual transmission have shown significant efficacy. Poor adherence may have contributed to the lack of effect in some of these trials. In this paper we explore the impact of various levels of adherence on measured efficacy within an RCT. ANALYSIS We used simple quantitative metho...

Variance estimators are derived for estimators of the average lead time and average benefit time due to screening in a randomized screening trial via influence functions. The influence functions demonstrate that these estimators are asymptotically equivalent to the mean difference, between the study and control case groups, in the survival times. For estimating benefit time, the survival time i...

THE EFFECT OF PRENATAL EXERCISES ON PRETERM CHILDBIRTH AND NEONATAL CONSEQUENCES OUTCOMES IN PRIMIPAROUS PREGNANT WOMEN: A RANDOMIZED CONTROLLED CLINICAL TRIAL STUDY

BACKGROUND A criticism of Randomized Controlled Trials (RCTs) in primary care is that they lack external validity, participants being unrepresentative of the wider population. Our aim was to determine whether published primary care-based RCTs report information about how the study sample is assembled, and whether this is associated with RCT characteristics. METHODS We reviewed RCTs published ...

Most discrete-event simulation models have stochastic elements that mimic the probabilistic nature of the system under consideration. A close match between the input model and the true underlying probabilistic mechanism associated with the system is required for successful input modeling. The general question considered here is how to model an element (e.g., arrival process, service times) in a...

Level 1 Evidence Level 1 evidence can come in one of 2 forms: a randomized clinical trial, which is associated with low study errors (low P value, confidence interval which excludes 1, or a ‘‘negative’’ result associated with a power of over 80%), or a meta-analysis. A meta-analysis refers to a study that statistically synthesizes the results of numerous ‘‘underpowered’’ randomized clinical tri...

T HE RANDOMIZED CLINICAL TRIAL IS THE GOLD standard for evaluating a therapy, providing the highest evidence for the practice of evidence-based medicine. However, not all randomized clinical trials are informative and the success of the trial in demonstrating a valid treatment or diagnostic effect will depend on the elements of the study design. The purpose of this report is to highlight the es...

Background: There is challenge to find an effective treatment for tinnitus. Few studies were done on the effects of acupuncture on tinnitus. This study evaluated the effect of acupuncture on chronic non-pulsatile tinnitus. Methods: This randomized double-blind clinical trial was conducted from December 2014 to September 2015. Patients suffering from chronic non-pulsatile tinnitus were randomly...