Nutritional Epidemiology and Biostatistics
A.Y. 2024/2025
Learning objectives
The course aims at providing knowledge of appropriate methodological tools to evaluate, also through the critical analysis of the literature, the appropriateness and validity of studies and tools to quantify how nutrition can influence the health of a population. Moreover, define the most suitable type of study to answer questions related to the relationship between nutrition and health in the general population and the related computational methods, provide knowledge on the main analysis tools in nutritional epidemiology, and how to critically evaluate a scientific article.
Expected learning outcomes
At the end of the course, the student will be able to recognize the various types of studies used in the nutritional field, evaluate the possible biases, design appropriate ones according to the nutritional research question and critically read the reference literature.
Lesson period: First semester
Assessment methods: Esame
Assessment result: voto verbalizzato in trentesimi
Single course
This course can be attended as a single course.
Course syllabus and organization
Single session
Responsible
Lesson period
First semester
Course syllabus
The course is divided into two parts: in the first one the typical methods of medical statistics are mentioned with particular attention to the analysis of dietary data; the second one illustrates the methods of epidemiology when applied to the study of how, in a population, nutrition can affect health.
Medical Statistics
Assessment of the reliability of the methods of collection and measurement of biomedical data
1. Illustrate the concept of sample, population, estimate and parameter
2. Provide examples of systematic errors and random errors
3. Quantitative and qualitative variables
4. Variability of quantitative variables within subject and between subjects
5. Graphical representations of a distribution
6. Position and dispersion indices, and shape of a distribution
7. Indexes of accuracy and precision of a measure
8. Quantiles (quartiles, centiles)
9. Correlation and Kappa statistic
Gaussian model
10. Describe the characteristics of the gaussian model of the distribution of measurement errors
11. Interpretation of population data using the Gaussian model
Sample estimate of population parameters and sampling distribution
12. Illustrate the concept of sample variability. Distinguish the concepts of sample and population
13. Distinguish the concepts of sample estimation of a parameter and population parameter
14. Illustrate the meaning of distribution of the sample estimates
15. Illustrate the meaning of standard error of a sample estimate
Confidence interval and its interpretation
16. Concept of confidence interval and its interpretation
17. Calculation of confidence interval
Hypothesis test
18. Type I and type II error, concept of statistical power of a test
19. Calculation of sample size
20. Difference between statistical significance and clinical relevance
Elements of multivariate statistics
21. Factorial analysis for the determination of nutritional patterns.
Nutritional Epidemiology
Epidemiology basics (applied to a nutritional context)
22. Cause-effect relationship
23. The meaning of "risk" in the medical / healthcare field: risk / protection factors; disease determinants
24. Study design: difference between observational and experimental studies; ecological studies, case-control studies, longitudinal or cohort studies, intervention and community trials; clinical trials: randomization, placebo, simple and double blindness, ethics committee.
25. The phases of clinical studies: from phase I to phase IV.
26. Typical measurement errors in the conduct of epidemiological studies in the nutritional field: selection, memory; ecological fallacy.
27. The concept of confounding.
28. Measures of occurrence in epidemiology and clinical epidemiology: prevalence, incidence, cumulative incidence
29. Measures of association between risk factor and disease: absolute risk, attributable risk, relative risk, odds ratio
Specific characteristics of nutritional epidemiology
30. Dietary assessment: 24h recall; food diaries; FFQ.
31. Levels of dietary analysis: food intakes; nutrient intakes; dietary biomarkers; nutrients versus foods
32. Data base for the conversion of food into nutrients
Interpretation of results
33. Validation and reproducibility of dietary information: internal validation versus external validation
34. Reading and evaluation of scientific articles
Medical Statistics
Assessment of the reliability of the methods of collection and measurement of biomedical data
1. Illustrate the concept of sample, population, estimate and parameter
2. Provide examples of systematic errors and random errors
3. Quantitative and qualitative variables
4. Variability of quantitative variables within subject and between subjects
5. Graphical representations of a distribution
6. Position and dispersion indices, and shape of a distribution
7. Indexes of accuracy and precision of a measure
8. Quantiles (quartiles, centiles)
9. Correlation and Kappa statistic
Gaussian model
10. Describe the characteristics of the gaussian model of the distribution of measurement errors
11. Interpretation of population data using the Gaussian model
Sample estimate of population parameters and sampling distribution
12. Illustrate the concept of sample variability. Distinguish the concepts of sample and population
13. Distinguish the concepts of sample estimation of a parameter and population parameter
14. Illustrate the meaning of distribution of the sample estimates
15. Illustrate the meaning of standard error of a sample estimate
Confidence interval and its interpretation
16. Concept of confidence interval and its interpretation
17. Calculation of confidence interval
Hypothesis test
18. Type I and type II error, concept of statistical power of a test
19. Calculation of sample size
20. Difference between statistical significance and clinical relevance
Elements of multivariate statistics
21. Factorial analysis for the determination of nutritional patterns.
Nutritional Epidemiology
Epidemiology basics (applied to a nutritional context)
22. Cause-effect relationship
23. The meaning of "risk" in the medical / healthcare field: risk / protection factors; disease determinants
24. Study design: difference between observational and experimental studies; ecological studies, case-control studies, longitudinal or cohort studies, intervention and community trials; clinical trials: randomization, placebo, simple and double blindness, ethics committee.
25. The phases of clinical studies: from phase I to phase IV.
26. Typical measurement errors in the conduct of epidemiological studies in the nutritional field: selection, memory; ecological fallacy.
27. The concept of confounding.
28. Measures of occurrence in epidemiology and clinical epidemiology: prevalence, incidence, cumulative incidence
29. Measures of association between risk factor and disease: absolute risk, attributable risk, relative risk, odds ratio
Specific characteristics of nutritional epidemiology
30. Dietary assessment: 24h recall; food diaries; FFQ.
31. Levels of dietary analysis: food intakes; nutrient intakes; dietary biomarkers; nutrients versus foods
32. Data base for the conversion of food into nutrients
Interpretation of results
33. Validation and reproducibility of dietary information: internal validation versus external validation
34. Reading and evaluation of scientific articles
Prerequisites for admission
Basic knowledge of statistics, generally provided by the MED / 01 credits of the three-year-long degrees. In particular, basic concepts of descriptive statistics are supposed to be garanted. Furthermore, it is assumed that the students are able to read scientific articles published in English.
Teaching methods
The course (6 CFU total) includes hours of formal teaching (frontal lessons) and non-formal teaching (exercises).
All the material presented in class is stored on a specific ARIEL website. Furthermore, in ARIEL scientific articles in English are made available to the students to deepen the topics covered in class and additional exercises related to the various modules of the course are available too.
All the material presented in class is stored on a specific ARIEL website. Furthermore, in ARIEL scientific articles in English are made available to the students to deepen the topics covered in class and additional exercises related to the various modules of the course are available too.
Teaching Resources
During the course, articles and handouts in Italian and English will be made available to students in ARIEL.
W. Willett Nutritional Epidemiology Oxford press 2 ed.
W. Willett Nutritional Epidemiology Oxford press 2 ed.
Assessment methods and Criteria
The aim of the examination is to verify the theoretical / methodological knowledge acquired by the student, his/her ability to correctly apply descriptive and interpretative models to small sets of real data and finally to evaluate the results of a clinical, experimental or observational study, also through the critical analysis of the medical literature.
The exam is written and oral.
The written examination will take place in a computer room using the Moodle platform for online exams to which the browser SEB (Safe Exam Browser) is associated and consists of multiple choice questions. A score is assigned to each question; students will know the score given to them for each question, if the answer is correct. The sum of the scores gives the mark of the exam, expressed in thirtieths.
During the written test, the students will be allowed to use all the material they deem appropriate (books, course slides, or notes), but will not be allowed to use any electronic devices (mobile phones, iPads, etc.). It is also necessary to use a calculator to perform correctly the calculations.
The results of the written test are communicated to the students on the ARIEL website.
The oral exam will consist of an individual written report of analysis and interpretation of a scientific article, compulsorily agreed with the teacher, which deals with a topic of nutritional epidemiology. This article will be discussed in the oral exam.
The final mark is the arithmetic mean of the marks obtained in the two (i.e., written and oral) exams.
Students with DSA and disabilities are asked to contact the Teacher via email at least 15 days before the scheduled exam date to agree on any individualized measures. In the email addressed to the teacher it is necessary to CC the respective University Services: [email protected] (for students with DSA) and [email protected] (for students with disabilities)
The exam is written and oral.
The written examination will take place in a computer room using the Moodle platform for online exams to which the browser SEB (Safe Exam Browser) is associated and consists of multiple choice questions. A score is assigned to each question; students will know the score given to them for each question, if the answer is correct. The sum of the scores gives the mark of the exam, expressed in thirtieths.
During the written test, the students will be allowed to use all the material they deem appropriate (books, course slides, or notes), but will not be allowed to use any electronic devices (mobile phones, iPads, etc.). It is also necessary to use a calculator to perform correctly the calculations.
The results of the written test are communicated to the students on the ARIEL website.
The oral exam will consist of an individual written report of analysis and interpretation of a scientific article, compulsorily agreed with the teacher, which deals with a topic of nutritional epidemiology. This article will be discussed in the oral exam.
The final mark is the arithmetic mean of the marks obtained in the two (i.e., written and oral) exams.
Students with DSA and disabilities are asked to contact the Teacher via email at least 15 days before the scheduled exam date to agree on any individualized measures. In the email addressed to the teacher it is necessary to CC the respective University Services: [email protected] (for students with DSA) and [email protected] (for students with disabilities)
MED/01 - MEDICAL STATISTICS - University credits: 6
Practicals: 16 hours
Lessons: 40 hours
Lessons: 40 hours
Professors:
Edefonti Valeria Carla, Ferraroni Monica
Shifts:
Professor(s)
Reception:
For meetings, please write an email.
via Celoria, 22, 20133 Milano