Data
Official data in SubjectManager for the following academic year: 20242025
Course director

Pótó László
associate professor,
Institute of Bioanalysis 
Number of hours/semester
lectures: 14 hours
practices: 14 hours
seminars: 0 hours
total of: 28 hours
Subject data
 Code of subject: OSEMETT
 2 kredit
 Dentistry
 Elective modul
 autumn

Course headcount limitations
min. 5 – max. 200
Topic
As a first course in statistics it covers the following main blocks: Basic data handling and computer use. Exploring data by graphical and numerical characterization. Basic concepts of probability and statistical inference. The basic methods for statistical inference most frequently used in medicine. These are the traditional goals in all first course in statistics – in all university level of educations.
The second (main) goal of this course (over on the previous ones) to focus on the power of statistical thinking; that is new to students and increasingly important at medical field  not only in the science but also in everyday work at the bedside. So not only as a scientific background but as parts of the everyday work are indispensable the skills and competences which can be laid down and improved by practicing statistics. Most importantly are such the analytical and critical thinking (or: on this field the statistical thinking). Based on this second goal we introduce students to the basics of Medical Decision Making. This is actually the third goal of our course. Because of those second and third goal our course is covering much more than a traditional first statistical class. This course is building also fundamental skills and competences for the daily medical work. An excellent example is the 20202021 COVID pandemic. It is attached a ‘COVIDspecial’ block to every class material now. We study and analyze the data of the pandemic  based on the two new course goals. It demonstrates the power of data analysis to our professional and private life decisions. COVID pandemic – is a real hot issue, isn’t it?
New improvement is the plenty online study material. Another improvement is: there are separated Alevel blocks (first of all) for those students
 who are better prepared as to the knowledge and thinking skills (for studying statistics) and / or
 those students who are considering a potential research or university professor career in their future.
Lectures
 1. Introduction (Statistics in medicine, the 3 main goals of the course, how to learn). Probability and relative frequency.  Pótó László
 2. Variables, Discrete distributions (binomial and Poisson).  Pótó László
 3. Continuous variables. Histogram, relative frequency density and probability density function.  Pótó László
 4. Mean and standard deviation. The normal distribution.  Pótó László
 5. Distribution of the sample mean, standard error.  Pótó László
 6. Confidence interval for the expected value. The t distribution  Pótó László
 7. Principle of hypothesis testing. The one sample and the paired samples t tests. The sign test (preview).  Pótó László
 8. The confidence interval and the hypothesis testing. Type I and type II errors. MDM basics 1/1.  Pótó László
 9. The independent samples t test. The F test.  Pótó László
 10. Linear regression and correlation.  Pótó László
 11. Contingency tables 1. The chisquared test. Medical tests. Sensitivity and specificity predictive values. (Contingency tables 2/1). MDM basics 1/2.  Pótó László
 12. The nonparametric tests (sign test, Wilcoxon and MannWhitney tests).  Pótó László
 13. The principle of the ANOVA. Summary of the hypothesis testing methods.  Pótó László
 14. Medical tests. Sensitivity and specificity, predictive values. (Contingency tables 2/2). Multivariable methods. MDM basics 2. MDM basics 2. Summary.  Pótó László
Practices
 1. Probability examples 1. Relative frequency and probability.  Pótó László
 2. Probability examples 2  discrete (Binomial and Poisson) distributions.  Pótó László
 3. Exploring data by graphs. Continuous variables. Histogram.  Pótó László
 4. Exploring data by numbers  descriptive statistics  Pótó László
 5. Normal distribution. The distribution of the sample mean.  Pótó László
 6. Estimations. The confidence interval of the expected value.  Pótó László
 7. The hypothesis testing  the `five steps`. The one sample (and the paired samples) t tests. The sign test.  Pótó László
 8. Estimation and hypothesis testing. The Type one and Type two errors. Basics of MDM  Part 1  Pótó László
 9. The independent samples t test.  Pótó László
 10. The linear regression and correlation.  Pótó László
 11. Contingency tables  the chisquares test. Basics of MDM  Part 2  Pótó László
 12. Nonparametric tests (Sign test, Wilcoxon test, MannWhitney test)  Pótó László
 13. Summary  Part 1: One variable methods  Pótó László
 14. Summary  Part 2: Two (and more) variables. Integration of MDM basics  Pótó László
Seminars
Reading material
Obligatory literature
1, D.S. Moore: The Basic Practice of Statistics, 7th ed., 2015
Literature developed by the Department
Course material on the Moodle (continuously upgraded and copleted script, video, mp3, basic and advanced level exercises and solutions, ...)
Basic (B) and advanced (A) curriculum units are chosen separately. Level B material and requirements require a very limited weekly study time. Accordingly, however, their longterm usefulness and the skills (scope and level) that can be acquired are also highly limited. In contrast, level A represents a kind of elite training goal. This requires significantly more practice  but it brings significant longterm benefits to the students. Both in terms of their knowledge, skills and attitude. At the same time, the possibility to switch between the two levels is open throughout the course.
Notes
L. Pótó: Biometrics. Workbook for the Practices, Pécs, 2020
Recommended literature
2, D.S. Moore, G.P. McCabe: Introduction to the Practice of Statistics, 5th ed., W.H. Freeman 2005
or:
D. Yates, D.S. Moore, D.S. Starnes: The Practice of Statistics (TI83/89 Graphing Calculator Enhanced) 2/e, 2003, W.H. Freeman
or
3, W.G. Rees: Essential Statistics, Chapman and Hall, 1992
Conditions for acceptance of the semester
As an optional subject, the exam materials are connected to an optional and nonmandatory exam for the purpose of 'selftest'. Active participation is enough to complete the course. Those who want to check their knowledge and skill development achieved through the course can do so in an optional exam.
Midterm exams
At least two tests can be completed during the semester, but the same is true for this as for the exam. It is optional, not a condition for completing the subject.
Making up for missed classes
Extra class
Exam topics/questions
On the optional semester exam: A written entry test, one data analysis problem solved by the SPSS and two theory questions from the below list. One of them is out of the MDM questions.
1. The main goals / potential results of learning biometrics/biostatistics
Why should we introduce a ‘new’ way of thinking when working in medicine? What is Statistics (as a field of science) in this context? The main points to learn in a first course of statistics.
Why is this a ‘skilloriented’ course? What should we develop and how to do it? Give some examples of this 2nd goal (analytical / statistical thinking) from the course, please.
How did we use all these for the 3rd goal (basics of MDM) – explain a few points to this using some examples, please!
What is your own conclusion then: Why was it worth to learn statistics for you – in 23 sentences?
(Mainly from the lectures 1, 3, and 678 and 1114.)
2. The key feature of the statistical thinking  the probability
Show this term  use a simple example, please. When can it be (and when cannot be) calculated? The relative frequency and probability: How did we proved that the probability can be ‘measured’ (estimated) by the relative frequency? Illustrate how both ways can be used in practical medical situations  by some examples.
(Mainly from the lectures 1, 2, 678 and 12)
3. The idea of the probability distribution  discrete distributions  1,
Demonstrate on the example of the binomial distribution how the probability calculations (games of chances case) can be used in real life situations. How can you illustrate a distribution (graphically). Trace its role on the decision making.
(Mainly from the lectures 2, 678 and 12)
4. The idea of the probability distribution  discrete distributions  2,
Contrast the binomial and the Poisson distributions: similarities and differences  demonstrated by some examples. Show the importance of discrete distributions trough examples. (Which hypothesis testing methods are based on this approximation?)
(Mainly from the lectures 2, 678 and 12)
5. The basic principles of statistical thinking  from the data to the decision
The way to the decision  and some pitfalls. (Size of the sample, representativity, lurking variables, probability decision, risk of errors,  and handling them)
(Mainly from the lectures 3 and 678)
6. Types of the data (variables) and displaying them with graphs
The three most frequent types of data and the methods for summarizing and displaying them.
Applications of some diagrams  strength and weaknesses. What specific info can be observed from a given type of graph? When to choose a given type?
(Mainly from the lecture 3 and 10)
7. The population and the sample
Explain both terms in case of some different types of data. How to characterize (by pictures or numbers) the sample and the population in these examples? Discuss the basic role of both terms in the statistical inference and decision making, please.
(Mainly from the lectures 2, 3, 678 and 12)
8. Numerical description of continuous data
Contrast the ‘five number’ and ‘three number’ descriptions. When to use one and when the other?
Prove and demonstrate by examples the basic role of the two description while selecting the appropriate decision making (or hypothesis testing) method.
(Mainly from the lectures 4, 678 and 12)
9. The idea of the probability distribution  continuous distributions
Symmetrical and skewed distributions. How the measures of the sample show (mirror) the shape of the distribution? Demonstrate them on the example of the normal and some skewed distributions. Prove the importance of distinction between them (think to the condition of the decision making methods).
(Mainly from the lectures 4, 678 and 12)
10. The normal distribution 1
Features. Why is it so frequently used in biology and medicine?
Application examples (reference range, ...).
How does the ?normal approximation? method demonstrate its importance (application examples) ... and how does the conditions of the hypothesis testing methods?
(Mainly from the lectures 4, 5, 678 and 12)
11. The normal distribution 2
How the ‘distribution of the mean’ shows its importance? Verify the basic role of the ‘distribution of the mean’ while statistical inference and decision making.
(Mainly from the lectures 4, 5, 678910)
12. Statistical inference
The statistical inference is the main goal (final step) of the statistical thinking. Contrast the point and the interval estimation from this point of view. Trace both methods (and the use of them) on the example of the confidence interval for the expected value (the p% CI of the expected value).
(Mainly from the lectures 5 and 6)
13. The confidence interval of the population mean
You can find the ?95% CI? on most of the SPSS output (that you learned). What is that and why can you meet it so frequently at statistical analysis? Give examples of results screens (methods): why is it included in the given method  what is the use of it there?
(Mainly from the lectures 5 and 6  and all the lectures from then)
14. The basic idea of hypothesis testing
Prove the relevance of the ?five steps? method  and demonstrate it on everyday and medical examples. What are the simple given steps of the ?five? and those that are require personal evaluation from case to case? Discuss these later ones on examples.
(Mainly from the lectures 7  and all the lectures from then)
15. The one sample and the paired t test
At what kind of data (structure) should you use this method? When hypothesis testing? Relate the two methods to each other. What can be done when the application conditions do not fit? Why not use these later methods at all the situations than?
(Mainly from the lectures 6789 and 12)
16. The confidence interval and the hypothesis testing
Contrast the two methods: similarities and differences  strength and weaknesses.
Demonstrate your evaluation on examples.
(Mainly from the lectures 678)
17. The risk of errors and the power of a test
Discuss the essential feature of the statistical decisions the risk of errors. How can you handle these risks? When should you handle these risks?
Explain on examples: when can you use the value of the risk of a certain error and when to use the power of the test? (Which questions call for this kind of answers?)
(Mainly from the lectures 8 and 9)
18. The two (independent) samples t test
Contrast the paired and independent samples t tests? What are the typical questions which call for the later method? What is the specific requirement (condition) of this method  and how can you handle this with the help of the F test?
(What should we pay for that solution? Why not to use always the solution which has less requirements?)
(Mainly from the lecture 9)
19. Connection between two variables  continuous variables
Contrast the one variable  two samples and the two variables  paired data (one sample) cases. What are the typical questions in the two cases?
Use examples to explain the method of the linear regression and correlation analysis. Stress the steps where there is an obvious role of statistical thinking.
Is this method a hypothesis test?
(Mainly from the lecture 10)
20. Connection between two variables  categorical variables
Relate to each other the two variables methods for continuous and categorical variables  similarities and differences. Which numbers are to be evaluated in the later case?
Which hypothesis testing method(s) are available for that? Explain the five steps on an example. What are the conditions for applying the method(s) and what to do when those conditions are not valid?
(Mainly from the lectures 11 and 12)
21. Evaluation of frequency data  1.
Why the chisquares test is not applicable in the medical practice frequently? What to do then? When to use the Fisher’s exact test  out of those cases? What the exact word means in the name?
(Mainly from the lectures 11 and 12)
22. Evaluation of frequency data  2.
How to qualify a diagnostic test? Which questions can be answered by the sensitivity, specificity and the predictive value(s) of the test? The special features / problems of the predictive values.
The confidence interval for the proportion. Explain (using the previous term) why the chisquares test gives ?not significant? result at evaluations of medical data frequently.
(Mainly from the lectures 11 and 12)
23. Nonparametric tests  1.
When to refuse the application of a t test  and when to apply the sign test instead? Demonstrate the ‘five steps’ on an example using the sign test. Contrast this method and the appropriate parametric one? What are the strength and weaknesses of this method?
(Mainly from the lectures 2, 7 and 12)
24. Nonparametric tests  2.
When to refuse the application of a t test  and when to apply the Wicoxon and the MannWhitney test instead? Demonstrate the application of both tests on examples. Contrast these methods and the appropriate parametric ones? What are the strength and weaknesses of these methods?
(Mainly from the lectures 2, 9 and 12)
25. The principle of the ANOVA
Demonstrate the application of the ANOVA method on an example
What is the basic idea of the evaluation? Illustrate it on the case of comparing several group means simultaneously.
What is the strength of this method in contrast to the several t tests for pairs of groups?
(Mainly from the lectures 2, 8, 9 and 13)
MDM1 Medical Decision Making  basic principles 1
Demonstrate please the application of statistical decision making terms and principles (Ho, Type1 and 2 error risks, change the alpha decision borderline, the evaluation of medical test results and symptoms; the 4 measures especially the issues of the positive and negative test predictive values in different test situations: at the clinic or screening tests, ...) to a simple medical or any everyday life decision making situation.
Use your calculation exam problem or select your own problem for demonstration.
(Mainly from the lecture 8 and 1112.)
MDM2 Medical Decision Making  basic principles 2
Demonstrate please the application of statistical decision making terms and principles (validities of examination results, clinical evidences, probabilities, treatment borderline, further examination options ...) to a simple medical decision making situation.
Use your calculation exam problem or select your own problem for demonstration.
(Mainly from the lectures 1112 and 14)
Examiners
Instructor / tutor of practices and seminars
 Pótó László