Sample size estimation: a glimpse beyond simple formulas.

نویسنده

  • John Eng
چکیده

Small increments in the complexity of clinical studies can readily take sample size estimation and statistical power analysis beyond the capabilities of simple mathematic formulas. In this article, the method of simulation is presented as a general technique with which sample size may be calculated for complex study designs. Applications of simulation for determining sample size requirements in studies involving correlated data and comparisons of receiver operating characteristic curves are discussed.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Comparing two Formulas of Sample Size Determination for Prevalence Studies

Background and purpose: Sample size and its determination is one of the most important problems in health researches. Calculating sample size for prevalence studies is one of the common questions of sample size topics. Minimum sample size with least complexity is desirable in order to achieve the basic goal of these studies. This study aims to compare two formulas of sample size calculation for...

متن کامل

آیا می‌خواهید مفهوم حجم نمونه و توان آزمون‌های آماری را عمیق‌تر درک نمایید؟

Sample size estimation is one of the crucial issues in the research methodology in medical sciences. It is an important issue for not only researchers but also readers of medical papers their frequent questions show how much they need to simple but accurate information. This paper presents the basic concepts of sample size calculation, and simplifies complicated issues using concrete example...

متن کامل

Estimation of the simple correlation coefficient.

This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applicati...

متن کامل

Sample size estimation for repeated measures analysis in randomized clinical trials with missing data.

In designing longitudinal studies, researchers must determine the number of subjects to randomize based on the power to detect a clinically meaningful treatment difference and a proposed analysis plan. In this paper, we present formulas for sample size estimation and an assessment of statistical power for a two-treatment repeated measures design allowing for subject attrition. These formulas ca...

متن کامل

تعیین حجم نمونه در داده های دوتایی برای دو گروه مستقل در مطالعات پزشکی

Backgound and Objectives: Nowadats, it is very common to investigate the effect of a new method or medicine by using a comparison between two independent groups in many clinical studies, but unfortunately the sample size part has not been done based on scientific formulas but on practical issues in some researches of this type of cinical studies, and this makes some unreliable results. Therefor...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Radiology

دوره 230 3  شماره 

صفحات  -

تاریخ انتشار 2004