Different analyses of recurrent events data, Applied Statistics

Assignment Help:

Different analyses of recurrent events data:

The bladder cancer data listed in Wei, Lin, and Weissfeld (1989) is used in Example 54.8/49.8 of SAS to  illustrate different analyses of  recurrent events data using different models. The data consist of 86 patients with superficial bladder tumors, which were removed when the patients entered the study. Of these patients, 48 were randomized into the placebo group, and 38 were randomized into the thiotepa group. Many patients had multiple recurrences of  tumors during the study, and new tumors were removed at each visit. The data set contains the first four recurrences of the tumor for each patient, and each recurrence time was measured from the patient's entry time into the study. The data consist of the following eight variables:

  • Trt, treatment group (1 =placebo and 2=thiotepa)
  • Time, follow-up time
  • Number, number of initial tumors
  • Size, initial tumor size
  • Tl, T2, T3, and T4, times of the four potential recurrences of the bladder tumor. A patient with only two recurrences has missing values in T3  and T4.

Write the formulae of the proportional intensity and the proportional mean models estimated using appropriate SAS procedures (define the relevant variables, functions, parameters and identify the formulas for two models) using the covariate x (x=O for placebo and x=l for thiotepa). What are the variance estimates for these two regression estimates (specify their numerical values and the names of the estimators )?

Interpret the main results of the analyses of bladder cancer data under these two models. Are the key modeling assumptions of these analyses are justified (provide relevant plots with explanations)?


Related Discussions:- Different analyses of recurrent events data

Simple regression, Simple Regression: The Teacher Preparation Researc...

Simple Regression: The Teacher Preparation Research Team conducted a study of college students who took the Praxis II-a teacher certification examination. Some variables from

Sampling, Sampling A  Population  is a collection of all the data point...

Sampling A  Population  is a collection of all the data points being studied. For example, if we are studying the annual incomes of all the people in India, then the population

Calculate the line of best fit, The manager of Pizza Hut provides a deliver...

The manager of Pizza Hut provides a delivery service for customers who telephone in an order. The manager would like to give callers an idea of the time it will take to deliver an

Probability distribution and sampling distribution , a 100 squash balls are...

a 100 squash balls are bounce from height of 100 inches with average height 30 inch with standard deviation 3/4 inch. a ball is fast if bounce above 32 inch. what is chance of gett

Data project, Dr. Jim Mirabella UNIT EIGHT: DATA ANALYSIS PROJECT All Excel...

Dr. Jim Mirabella UNIT EIGHT: DATA ANALYSIS PROJECT All Excel output should be copied into a single Word document where you must enter all of your responses to the questions below.

Conduct a hypothesis testing, Celia is a nurse in a geriatric ward.  She no...

Celia is a nurse in a geriatric ward.  She noticed that older persons in her care are having problems sleeping at night.  She decided to introduce non-pharmocologic ways of relaxat

Difference in goals between pca and fa, In PCA the eigknvalues must ultimat...

In PCA the eigknvalues must ultimately account for all of the variance. There is no probability,'no hypothesis, no test because strictly speaking PCA is not a statistical procedure

Box plots, This box plot displays the diversity wfood; the data ranges from...

This box plot displays the diversity wfood; the data ranges from 0.05710 being the minimum value and 0.78900 being the maximum value. The box plot is slightly positively skewed at

General algebraic and quantitative expressions, Read the following data on ...

Read the following data on the economy of Angoia and answer/respond to the questions/instructions that follow. Unless otherwise stated, the monetary figures are in real billions o

Data reduction, The PCA is amongst the oldest of the multivariate statistic...

The PCA is amongst the oldest of the multivariate statistical methods of data reduction. It is a technique for simplifying a dataset, by reducing multidimensional datasets to lower

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd