1. Study/Research protocol
Introduction to Intervention Epidemiology
Tunis, 4 November 2014
Presented by Dr Nada Ghosn
Ministry of Public Health - Lebanon

2. Sources
FEM WIKI
Writing a Study Protocol

3. Objectives
Overview of different elements to include in a research protocol
Understand the steps for writing a study protocol

4. The life cycle of an epidemiological study/investigation
Needs for data
Involving the programme
Study question
Recommendations
Study objective(s)
Conclusions
Analysis plan
Analyse data
Data collection instruments
Collect data 4

5. Protocol elements 1. Presentation 2. Background and justifications
3. Objectives
4. Methods
5. Ethical considerations
6. Project management
7. Timetable
8. Resources
9. References
10. Appendices

6. 1. Presentation Title Short, accurate, concise Authors: Investigators
Main centres
Steering committee (if present)
Summary of the protocol

7. 2. Background and justification
Statement of problem, study justification
Importance of subject area: magnitude, frequency …
Literature review: relevant ones, gaps in existing knowledge
Study question: Principal questions to be addressed
Expectation: contribution of results to existing knowledge, use of results,
Information for action

8. 3. Study objective(s) Study objective Formulate hypothesis
Should answer the study question
Formulate hypothesis

9. 3. Study objectives S.M.A.R.T. objective Number of objectives Specific
Measurable
Action oriented
Realistic
Time related
Number of objectives
One objective
or one principal + other secondary

10. 3. Study objectives: the verb
Written in epidemiological terms
Verb: one verb per objetive
“Determine” for hypothesis testing
“Determine whether a contaminated product from bakery A caused an hepatitis A outbreak”
“Estimate” for measuring indicator (s)
“Estimate the prevalence of TB”

11. 3. Study objectives: Hypotheses
Hypothesis: Translation of the objectives in terms that allow statistical testing
“Hospitalisations rates due to severe RV are lower in children vaccinated against RV than in unvaccinated children”

12. 3. Study objectives: SMART
Which one is SMART?
By the end of this study …
“To measure the effectiveness of rotavirus (RV) vaccine”
“To estimate the effectiveness of full course of RV vaccine in reducing rates of hospitalizations of severe RV gastroenteritis”

13. 3. Study objectives: SMART?
By the end of this study …
"To identify risk factors for HCV infection"
"To determine if sharing a haemodialysis machine with a HCV infected patient is a risk factor for HCV infection“
"To identify failures in procedures designed to prevent cross-infection via haemodialysis machines"
“The incidence of HCV infection in haemodialysis patients is higher in patients sharing machines with HCV infected patients than in patients not sharing machines with HCV infected patients”

14. 4. Methods The “Methods” section:
Describes specific details of the procedures to achieve the study objectives
What? And How?
Judging the validity of the proposal: rely on the methodology

15. 4. Methods Elements: Study design Study population
Sampling procedure and sample size
Definitions
Analysis plan
Data collection
Data handling
Pre-testing or pilot studies
Limitations

16. 4. Methods: a)Study design
Choose design according to objectives
Descriptive (cross-sectional …) or analytic (cohort, case control)
Brief justification

17. 4. Methods: b) Study population
Definition
By time, place and person
Ex: “children < 5 years residents in the catchment area of participating hospitals”
Selection
Criteria for inclusion and exclusion
Mechanisms of recruitment
Follow up (if needed)
Representativeness

18. 4. Methods: c)Sample design & size
Sampling design
Sampling unit
Frame: registry of all units of the population
Sampling schema /method: simple random sampling, systematic, stratified, cluster …
Randomisation procedures
Replacement procedures (in case of refusal)
Sample size
Sample size and power calculations

19. 4. Methods: d)Definitions
Exposures: risk factors, protective factors, confounding factors
Outcomes: case, control group

20. 4. Methods: d)Definitions
Cohort:
? "consumption of custard slices in June or July 1991, in South-West Wales “?
? "a person living in South-West Wales with a laboratory confirmed infection due to S. Enteritidis in June or July 1991“?

21. 4. Methods: d)Definitions
Case control
? “Persons reported from the weekly notifications from reference laboratory having S. Enteriditis infection”?
? “Persons living in SW Wales in same neighborhood as cases“
? Random selection of people using telephone directory ?

22. 4. Methods: e) Analysis plan
Structured based on the objectives
Descriptive and analytical
Dummy tables = expected tables with empty cells
Define indicators to be used
Statistical tests to be used

23. 4. Methods: e) Analysis plan
CONTENT:
Descriptive
Cases: nb, %, rates, ratio
Time, place, person
Disease, exposure
Analytical
Crude analysis: 1 exposure & 1 outcome
Stratified analysis: 2 exposures & 1 outcome
Multivariable analysis: several exposures

24. Multivariable analysis
4. Methods: e) Analysis plan - content
Descriptive
Data description
Generate / Recode
New variables
Descriptive analysis
Time, place, persons
Analytic
Crude (univariate)
analysis
Stratified analysis
Multivariable analysis

25. 4. Methods: e) Analysis plan – dummy tables
Dummy tables = expected tables with empty cells
Descriptive results
Comparison of groups (cohort, case control)
Dose response relationship for key exposures (if appropriate)
Stratification: possible confounding factors / effect modifiers (if appropriate)

26. Dummy table - Descriptive
Males
Females
Age
group
Total
Cases
AR%
< 10 y
10 – 19 y
> 19 y
Unknown

27. Dummy table – cohort studies
Food specific attack rates

28. Dummy table - Case control studies
Case control study risk factors for brucellosis in France, 1999 28

29. Dummy table – Dose response
Cheese cake
Total
Cases
AR% RR
Reference 1 2
>= 2
Unknown

30. Dummy table – Stratified analysis
Age
< 30 y
Cheese cake
Total
Cases
AR% RR
Yes No
> 30 y

31. 4. Methods – e) Analysis plan: Indicators
List indicators to be generated
Rates, ratio, proportions or quantitative variables
E.g.: RV vaccine coverage, food specific attack rates
Identify information to calculate indicators
Numerators and denominators
E.g.: children vaccinated / total children, eating cheese / total number of participants

32. 4. Methods – f) Data collection
How?
Interview (face to face, telephone …), observation, record review, lab sample
By whom?
Interviewers: selection, training
Supervision
Tools
Questionnaires, recording materials
If questionnaires: self or interviewer administered
Blind data collection?
Procedures for taking specimens

33. 4. Methods – f) Data collection
Identify variables needed to reflect the needed information
E.g.:
“RV vaccination status”,
“eat cheese Y/N”
Identify data collection method for each variable
Review vaccination cards or interview of the mother
Interview participants

34. 4. Methods – f) Data collection
D) Exposure
11. Cheese
1. Yes
2. No
11.
|__|
12. Ice cream
12.
13. Salad
13.
14. Cheese cake
14.

35. 4. Methods – g) Data handling
Coding
During data collection, afterwards?
By whom?
Processing
Software, hardware
Data entry
During the study, afterwards?
Single entry, double entry?
Validation and data cleaning

36. 4. Methods – h) Pilot / pre test
No study without pre-test
To assess the feasibility of sampling
To verify data collection methods and to test the questionnaire

37. 4. Methods – i) Limitations
Identification of potential sources of biases
Selection bias
Information bias
How to deal with them
Potential correction
Expected impact on the results

38. 5. Ethical considerations
Informed consent
Oral? written?
Translated in local language
Confidentiality
Coding data and entering data without identifier
Data storage and protection
Ethical committee

39. 6. Project management Participating institutions and persons
Responsibilities and tasks of each partner
Data ownership:
Who can access the data?
Who will provide clearance to publish the results?

40. 7. Timetable
Planning/organisation of the study of various activities and tasks:
Writing the protocol,
Permission,
Obtain funding,
Purchase of material,
Recruitment of needed resources,
Training staff,
Data collection,
Data entry,
Data validation and cleaning,
Data analysis,
Report, article …
Establishing milestones and deadlines

41. 7. Timetable

42. 8. Resources Resources: Human Equipment and material Laboratory tests
Information, training
Time
Specify
Available resources
Requested resources
Specify needed budget
Reasonable
Detailed
Well justified

43. 9. References Limit number of references to key articles
Follow recommended style
Vancouver

44. 10. Appendices Methodological appendices List of definitions
Questionnaires
Introductory letters to study participants
Forms for informed consent …

45. Introduction to Intervention Epidemiology
THANK YOU
Introduction to Intervention Epidemiology
Tunis, 4 November 2014
Presented by Dr Nada Ghosn
Ministry of Public Health - Lebanon