Restricted mean survival time as a summary measure of time‐to‐event outcome

Many clinical research studies evaluate a time‐to‐event outcome, illustrate survival functions, and conventionally report estimated hazard ratios to express the magnitude of the treatment effect when comparing between groups. However, it may not be straightforward to interpret the hazard ratio clinically and statistically when the proportional hazards assumption is invalid. In some recent papers published in clinical journals, the use of restricted mean survival time (RMST) or τ ‐year mean survival time is discussed as one of the alternative summary measures for the time‐to‐event outcome. The RMST is defined as the expected value of time to event limited to a specific time point corresponding to the area under the survival curve up to the specific time point. This article summarizes the necessary information to conduct statistical analysis using the RMST, including the definition and statistical properties of the RMST, adjusted analysis methods, sample size calculation, information fraction for the RMST difference, and clinical and statistical meaning and interpretation. Additionally, we discuss how to set the specific time point to define the RMST from two main points of view. We also provide developed SAS codes to determine the sample size required to detect an expected RMST difference with appropriate power and reconstruct individual survival data to estimate an RMST reference value from a reported survival curve.     

Gender and physical punishment: the filipino children's experience

This paper reports selected findings from a doctoral dissertation on Filipino children's attitudes towards physical punishment. The findings of this research stem from a survey of 270 grade‐six students in Iloilo, Philippines. The results indicated that the majority (61.1%) had experienced physical punishment at home. The most common punishment children received was pinching (74.5%), followed by beatings (49.7%). The chi‐square analysis revealed that more boys than girls were physically punished (p < 0.05). Mothers were found to be the most frequent users of physical punishment. The prevalence of physical punishment at home may be attributed to Philippine law which ‘allows parents to physically punish their children as may be necessary for the formation of his good character’ as reflected in Article 45 of Presidential Decree No. 603, known as ‘The Child and Youth Welfare Code’ (Article 45, PD 603). The tendency of Filipino parents to punish sons more harshly than their daughters could be explained in relation to how boys and girls are regarded in society. Boys are expected to be tough and brave. By administering harsher discipline, parents may believe they are moulding their sons to be strong and to prepare them to be future pillars of society. Copyright © 2010 John Wiley & Sons, Ltd.     

Effects of dutasteride on lower urinary tract symptoms: a prospective analysis based on changes in testosterone/dihydrotestosterone levels and total prostatic volume reduction

This study analyzed the effects of dutasteride on lower urinary tract symptoms based on the association between changes in the total testosterone (TT)/dihydrotestosterone (DHT) levels and total prostate volume (TPV) reduction. Sixty participants diagnosed with benign prostatic hyperplasia were given 0.5?mg of dutasteride daily for 52 weeks. Measures of TT and DHT levels, TPV and uroflowmetry were obtained before and after dutasteride treatment. Forty-three patients demonstrated a TPV reduction of ≥5% (Group 1), whereas the remaining 17 patients demonstrated a TPV reduction of <5% (Group 2). DHT suppression and DHT/TT ratio at baseline were significantly higher in Group 1 than Group 2. International Prostate Symptom Scores (IPSS) and uroflowmetry were significantly improved in both groups. In Group 2, nine patients demonstrated some improvement in IPSS (Group 2A), whereas eight did not (Group 2B). The rate of TT increase and improvement in voiding symptoms were significantly higher in Group 2A than Group 2B. Dutasteride-induced TPV reduction is dependent on individual 5-α reductase inhibitor activity. Some patients demonstrating smaller dutasteride-induced TPV reduction may experience an improvement in voiding symptoms owing to an increased level of testosterone.