KLMED8008: Analysis of repeated measurements 2016

This course is aimed at PhD students of medicine and health sciences.

Language

The lectures, textbook and the exercises are in English.

Contents and credits

Most commonly employed statistical procedures require that observations are independent. In this course we will discuss problems, advantages, and strategies for analysis of repeated measurements on the same individual or group.
The course gives 5 study credits (studiepoeng).

Prerequisites (Forkunnskaper)

Basically, this course builds on KLMED8005. Knowledge of and experience in multiple linear regression will prove very helpful.

Course supervisor

Professor Eirik Skogvoll, MD PhD, Dept. of Anaesthesia and Intensive Care Medicine, St.Olav University Hospital
Phone +47 725 74549
e-mail: eirik.skogvoll@ntnu.no

Textbook

Rabe-Heskett & Skrondal: Multilevel and Longitudinal Modeling Using Stata, Stata Press, 3rd ed. (2012), Volume I: Continuous Responses.
We will cover chapters 2 to 5 with some exceptions. Supplementary material from the lectures.
(The second edition of this book (2008) may also be used, but since then some Stata code and commands have changed).

Curriculum, textbook 2.nd edition

Curriculum, textbook 3.rd edition

Software

Basically, we will follow the textbook and use Stata. It will therefore be very useful to run Stata from your own computer and/or laptop during the course. However, you may very well use your favourite software to solve the exercises and the exam as long as you can interpret the results and present them clearly.

Stata (the current release is Stata SE 13.1) is available for students at the Faculty of Medicine via Calcfarm. Students from other faculties can get temporary access to Stata via Calcfarm; please contact the course administrator (see below) to activate this.
Disregard any start-up messages about updating, this is done automatically.
It will be useful to create a shortcut (see below).

Data files and do-files

Data files in Stata format (*.dta) and relevant do-files (Stata command files) that come with the book may be downloaded from the Textbook's website:
http://www.stata-press.com/books/multilevel-longitudinal-modeling-stata

Installing add-ons for Stata

If you would like to install add-ons (which may be very useful; e.g. glamm), it is necessary to tell Stata where the program should save the files.
You need to create two directories under your home catalog (the full path is shown here, and please substitute your username); e.g.

\\home.ansatt.ntnu.no\your_username\stata-data\personal
\\home.ansatt.ntnu.no\your_username\stata-data\ado

and then run the following commands either via a do-file or from the Stata prompt:

sysdir set PERSONAL \\home.ansatt.ntnu.no\your_username\stata-data\personal
sysdir set PLUS \\home.ansatt.ntnu.no\your_username\stata-data\ado

This may be done automatically at startup if the abowe two commands are found in a file named "profile.do", located in the Stata working directory.
A simple way to ensure that Stata starts in the appropriate directory is to create a shortcut on your computer or TS desktop. Choose shortcut properties, and specify that Stata should start in the directory where "profile.do" is found, e.g.

\\home.ansatt.ntnu.no\your_username\stata-data 

Enrolment (Påmelding)

Via StudentWeb. Complete this before study start. Closing date is 15.02.2016.
For students not registered at NTNU (For studenter uten studierett ved NTNU): please fill in the relevant application form: http://www.ntnu.no/dmf/forskning/phd/emner

Course administrator

Svanhild Stokkan Haugen
Phone +47 (735)  98899
Visiting address: Håkon Jarls gate 11 (Øya Helsehus)
e-mail: svanhild.s.haugen@ntnu.no

Course schedule as of June 1.st 2016.

Time: Wednesdays at 1215 - 1400 in LS41 (most of the time) or LS 42 (March 16th). Both are in the Laboratory building.

Week no.	Subject	Date and place	Lecturer	Literature
9	Day 1. Introduction. Problems and advantages with dependent observations. Review of variance, standard deviation, covariance and correlation. Brief introduction to Stata. Summary measures (mean, median, area under curve (AUC), slope coefficient, min/ max value) Review of multiple linear regression.	02.03.2016 LS41 1215-1400	Eirik Skogvoll	Slides Do-file Rabe-Heskett & Skrondal: Chapter 1 Matthews et al. (1990) Bland & Altman (1995) Rosner_6 Section 5.6: covariance and correlation Data sets (Stata format): X67 X67s gtube gtube_l
10	Day 2. Comparing groups with adjustment for baseline. Power and sample size determination. Brief discussion of ANOVA, repeated measurements ANOVA and Friedman's non-parametric test.	09.03.2016 LS41 1215-1400	Eirik Skogvoll	Slides Do-file Vickers & Altman (2001) Kinnear & Gray: Chapter 9 Rosner_6: section 12.6 Data sets (Stata format): Vickers lwiner winer wwiner
11	Day 3. Robust variance estimation in linear regression. Review of statistical models in general. Variance components.	16.03.2016 LS42 1215-1400	Eirik Skogvoll	Slides Do-file Rabe-Heskett & Skrondal: Chapter 2 Rosner_6: sections 12.8, 12.9
12	Day 4. Excercise no. 1. Voluntary, no hand-in. Lecturer present.	30.03.2016 LS41 1215-1400	Eirik Skogvoll	Exercise 1
13	Day 5. Review of exercise no 1. Power and sample size determination with clustered design. Linear mixed effect models. Random intercept models with covariates.	06.04.2016 LS41 1215-1400	Eirik Skogvoll	Slides Rabe-Heskett & Skrondal: Chapter 3 Gueorguieva, R. and J. H. Krystal (2004). Stata manual [XT] (pdf, comes with the program)
15	Day 6. Random coefficient models. Brief discussion of Generalized Estimating Equations (GEE).	13.04.2016 LS41 1215-1400	Stian Lydersen	Notes MixedModSPSS Rabe-Heskett & Skrondal: Chapter 4
16	Day 7. Excercise no. 2. Voluntary, no hand-in. Lecturer present.	20.04.2016 LS41 1215-1400	Turid Follestad	Do-file1 Do-file2 Exercise 2
17	Day 8. Review of exercise 2. Longitudinal models.	27.04.2016 LS41 1215-1400	Turid Follestad	Rabe-Heskett & Skrondal: Chapter 5 Notes Do-file1
18	Day 9. Longitudinal models (cont’d). Power and sample size determination. Presentation and discussion of students' own projects. Summing up, questions.	04.05.2016 LS41 1215-1500	Eirik Skogvoll Turid Follestad	Rabe-Heskett & Skrondal: Chapter 6 Do-file1 Do-file2 Do-file3 Notes

Suggested literature in addition to the textbook:

• Matthews, J. N., D. G. Altman, et al. (1990). Analysis of serial measurements in medical research. BMJ 300: 230-235.
• Bland JM, Altman DG. Calculating correlation coefficients with repeated observations: Part 1- correlation within subjects. BMJ 1995;310:446
• Rosner, B. Fundamentals of Biostatistics (5ht, 6th or 7th edition). Relevant sections on variance, standard deviation, covariance, correlation, and variance components.
• Gueorguieva, R. and J. H. Krystal (2004). Move over ANOVA: progress in analyzing repeated-measures data and its reflection in papers published in the Archives of General Psychiatry. Arch Gen Psychiatry 61(3): 310-7
• Detry, M. A. and Y. Ma (2016). Analyzing Repeated Measurements Using Mixed Models. JAMA 315(4): 407-408.
  
• Kinnear P, Gray C: SPSS 14 Made Simple (2006) Psychology Press
• Vickers, A. J. and D. G. Altman (2001). Statistics notes: Analysing controlled trials with baseline and follow up measurements. BMJ 323: 1123-4.
• Veierød, Lydersen & Laake (ed.) Medical Statistics in clinical and epidemiological research. Chapters 7 and 8. Oslo: Gyldendal 2012.

Exam

A "take home" exam referring to a dataset was handed out on June 1.st. Candidates should turn up in person at the Department of Community Medicine, Øya Helsehus. The dataset to be analyzed is no longer available.  Contact person: course administrator Svanhild Stokkan Haugen (stand-in Anne-Britt Hofstad), phone +47  (735)  97567.

If you are unable to attend, please contact Svanhild (stand-in Anne Britt Hofstad) and arrange for an e-mail with the exam instead.

The exam is to be analyzed and returned in 3 (three) copies within one week.