PHARMACEUTICAL
EPIDIMIOLOGY
,Contents
Learning objectives:.....................................................................................................................................3
Lecture 1: introduction................................................................................................................................4
Etiology and intervention VS diagnosis and prognosis:............................................................................5
Vaccine/drug development.....................................................................................................................5
Risk management plan (RMP):.............................................................................................................7
Experiments.........................................................................................................................................8
Drug classification systems..................................................................................................................9
Assignment............................................................................................................................................12
Lecture 2: Pharmacoeconomics.................................................................................................................12
Lecture 3....................................................................................................................................................14
Frequencies...........................................................................................................................................14
Association mainstem............................................................................................................................17
................................................................................................................................................................... 19
Lecture 4: Randomized Controlled Trials & Descriptive Studies................................................................21
Experimental Study:...............................................................................................................................21
Analytical studies designs..................................................................................................................21
Observational studies........................................................................................................................22
Lecture 5: Case-Control and Cohort Studies..............................................................................................25
Study Design..........................................................................................................................................25
The design of the research question..................................................................................................25
Data collection...................................................................................................................................28
Assingment............................................................................................................................................35
Lecture 6: Analytical studies......................................................................................................................36
Statistical models (regression analysis)..................................................................................................36
Conducting studies................................................................................................................................36
Types of errors.......................................................................................................................................37
Types of errors...................................................................................................................................37
Validity and precision.........................................................................................................................38
Kinds of Bias.......................................................................................................................................39
Effect modification.............................................................................................................................43
Lecture 7: Causality and Analysis...............................................................................................................44
, Four types of association.......................................................................................................................44
Causality................................................................................................................................................45
Causality criteria by Rothman............................................................................................................45
Validity analysis summary..................................................................................................................46
Precision............................................................................................................................................47
Tables.................................................................................................................................................48
College 8 – Systematic overview, meta-analysis, independent research...................................................51
Systematic reviews................................................................................................................................52
Meta-Analysis....................................................................................................................................52
College 9: statical methods in pharmacoepidemiology.............................................................................54
Additional information..............................................................................................................................55
,Learning objectives:
The student is able to reproduce and describe: the basic concepts of epidemiology (e.g. measures of
frequency and associations, research focus as etiology, diagnostics, prognostics and intervention,
main study designs, causality theory, validity and generalizability, basic data-analysis techniques,
systematic and random errors, effect modification, and basic pharmaco-economic concepts).
The student can evaluate the main research question, study design, study population, sources of
information, exposure and outcome, misclassification and types of biases (information bias,
selection bias and confounding) in a (pharmaco-)epidemiological study paper.
The student is able to calculate frequency measures, life-tables, association measures, standardized
effect measures (direct and indirect) and Mantel-Haenszel stratification measures.
The student can evaluate the pros and cons of different study designs (e.g. RCT, case-control,
cohort, prevalence study) and quality of measure instruments.
The student is able to calculate confidence intervals for different frequency measures and
association measures and to understand their value in relation to p-values.
The student is able to understand and judge elementary statistics such as statistical distributions and
statistical testing, and knows the basics of multivariate regression analysis such as linear, logistic and
Cox-regression analysis and can perform multivariate logistic regression.
The student has basic knowledge about data collection methods and can examine study data using a
statistical program and can interprete the statistical output.
The student is able to critically review a pharmaco-epidemiological study (article), to evaluate its
quality and present orally and in writing case-based studies.
The student has knowledge about basic concepts of pharmacoeconomics and regulations for drug
market access.
,Lecture 1:
introduction
What is epidemiology?
Epidemiology: is the science that studies the occurrence of a disease in large population of
people as a function of determinants.
Pharmaco-epidemiology is really about the scientific field that studies the contribution of
drugs in disease prevention and therapy in large populations.
Epidemiology is about binary situations
Left or right
What is meant with detriments?
Factors that help a disease to occur
E.g age in asthma
Why is it important to study epidemiology?
It is an essential science to conduct evidence-based medicine
How is epidemiology helps to conduct evidence based medicine?
In Pharmacoepidemiology there are 4 question to ask?
1-Diagnostics: say which disease the patient has
2- Etiology: المسبباتthe reason of the disease.
3- Prognosis: تنبؤfuture of disease.
4- Intervention تدخل: best treatment (therapy) or how to prevent the
disease (prevention).
Diagnosis
Intervention
Etiology Disease prognosis
No
Intervention
,Etiology and intervention
VS diagnosis and
prognosis:
What makes etiology and intervention characterized together?
Etiology and intervention: their studies are analytical studies, with causal associations
Why is it causal?
Since by removing the cause the disease vanishes
How to know that such data are causal associated?
These can be known after randomized control trials or case control studies.
Only one determinant is needed to determine them
confounding bias can occur. They are represented by explanatory statistical models.
What makes diagnosis and prognosis characterized together?
Diagnosis and prognosis: their studies are descriptive studies, with predictive associations.
Why is it predictive?
More than one determinant is needed to know them (age, other comorbidities, bad
habits and others. We need all of these to make, as much as possible, good predictions).
They are represented by predictive statistical models
No confounding bias can occur, since there are many factors
Summary
Vaccine/drug development
Vaccine/drug development always follows the following steps presented in the graph
,
Once the pharmaceutical industry gets the license to make the vaccine/drug, we go on to
the post
marketing phase where the pharmaceutical product is available for people to buy. This is the
postmarketing phase. During this phase the pharmacoepidemiologic research takes place
Epidemiological research happens here
How to make a research question related to epidemiology?
What is the use of drug X in patient Y and what is the variation between age and sex?
Drug A is the outcome in the study; the age and sex are the determinants of the
outcome and the patient Y is the study patient.
In this case; the use of drug X is the outcome. Patient Y is the study
domain/hypothetical student. Variation between age and sex: determinant of the
outcome. (We want to know something about the use of the drug X that is why it is
the outcome)
What is the effect of drug X in the treatment of disease Z on outcome Y
Drug X: is the determinant/exposure. Outcome Y: the outcome. Disease Z: the study
domain/hypothetical patient.
(Here is the effect of drug X important for us on the course of disease, that is why
drug X is the determinant that will determine the outcome Y).
,
Epidemiological questions to ask
1- What proportion of the population will take the drug.
2- What determinants predict the use of the drug.
3- Do drugs decrease the rate of mortality, and diseased cases or improve the quality of life.
4- The numbers and types of side effects of this drug?
Some time drug can be withdrawn form the market, what are the main reasons for withdrawing a
drug form the market?
1- clinical trials are not big as you think.
2- real world use of the drug differs; the trial group is mostly healthy group.
3- the short duration of trials.
4- off-label usage of the drug (e.g. the usage of an adult-drug by a child).
Children can NOT participate in clinical trials
How is interested in post marketing severance?
Medical agensy
Pharmaceutical industry
Patient
Health insurance
Risk management plan
(RMP):
What is RMP?
Documentary that contains the studies performed to increase the knowledge about the risks of
the drug.
, It is obligatory for pharmaceutical companies to have an RMP for ALL drugs released on the
market. That is done in order to detect the side effects that were not appeared during the
clinical trials.EMA and FDA should be stricter on pharmaceutical companies to give the RMP.
Black triangle on a drug means that this drug should be studied much more intensively. P.s.
direct-to-consumer advertising is prohibited in the first two years after registration
What does the black triangle mean?
Direct advertising to patient is not allowed for two years
Whom is the PMS relevant for?
1- Patient: he/she will get the drug and wants to know whether it is safe
and effective or not.
2- Physicians and pharmacists : they want to know whether the drug is effective and
safe or not, to
make a good decision whether the drug can be given to the patient or not.
3- Insurance company: they have to know it in order to make sure that there is
rational prescribing
with regard to costs.
4- Government: it is responsible for patient health.
5- Industry: need to know it in order to make better product, and sold it more!
Which sources can be used for PMS?
1- spontaneous reporting systems as LAREB (also patients can report).
2- Routine administrative database as GP databases or prescription databases.
3- Questionnaires or interviews (maybe internet based).
4- Cohort, physical testing or lab data
Experiments
, Descriptive studeis/cross sectioal
This mean that the experiment is done in one moment of time
The problem here we do not know which comes first
Outcome first or time first
Where is cross sectional used?
The diagnostic studies
Doctor I want to know what I have NOW
cohort studies
What is cohort study?
A cohort study is a type of observational study that follows a group of people who share a
common characteristic over time. Researchers collect data at different points in time to
understand how different factors affect the group’s health
Advantages of Cohorts:
1- fast.
2- large numbers.
3- Validation data → prevents recall bias.
4- You can get information about reference group or controls without disease.
5- Low costs.
6- Minimal effort done by the researcher.
Disadvantages of Cohorts:
1- Indication bias.
2- insufficient number of patients.
3- New drug (channeling).
4- No information about confounding bias.
5- Validity and completeness data dependent on the data source.
Leuk om te weten: ALUVIA anti-HIV drug which is used in China to treat corona nowadays.
Drug classification systems
ATC code
According ATC
This is maintain by WHO
ATC → Anatomical Therapeutic Chemical classification
system
7 positions; 5 hierarchical levels
- N1: 1 letter → Anatomical Main Group N
- N2: 2 digits → Therapeutic Main Group N 02
- N3: 1 letter → Therapeutic Subgroup N 02 B