Bias refers to a systematic distortion of results or inferences due to some factor in the design or conduct of the study. Some common types of bias include: - Selection bias - Systematic differences between those selected for the study versus those who were not selected. - Information bias - Errors in measuring exposures or outcomes. For example, recall bias if cases remember past exposures differently than controls. - Confounding - The effect of an extraneous variable that is associated with both the exposure and the outcome of interest. - Observer bias - When observers or investigators influence the results through their expectations or preferences. - Attrition bias - Systematic differences between those lost to follow up versus those who completed the study.

1. Introduction to participatory
epidemiology
Barbara Wieland (ILRI)
Livestock and Fish participatory epidemiology and gender training
workshop, Addis Ababa, 15-19 June 2015

2. IFAD project (2014-2017), Livestock and
Fish gender initiative (2015), Africa RISING
Need to understand disease priorities and how that
affects individual members of households
Identify and test appropriate interventions
Scaling out, policy recommendations

3. Disease priorities and their impact
Outline of project activities
• Training in participatory epidemiology and gender
• Field work, collation of research findings and
preliminary analysis
• Follow-up training on data analysis and
interpretation of results
• Training on sero-surveillance and planning of
epidemiological sero-surveys
• Sero-prevalence survey on key livestock diseases
• Identify and plan interventions

4. Agenda for this week
Training in PE and gender
Monday Tuesday Wednesday Thursday Frida
PE intro Gender Gender Develop tools
fieldwork
Practice
fieldwork
PE tools
Ranking
scoring
PE tools
SSI
PE tools
Analysis
Running FGD
Practice
fieldwork
Logistics

5. Ball bearing
What is epidemiology?
What is participatory epidemiology?
What is surveillance?

6. Epidemiology
Epidemiology is the study of diseases in populations
and of factors that determine its occurrence.
Pathogen
EnvironmentHost

7. Questions answered with epidemiology
• How much disease is present in this
population?
• What are the factors that make disease more
likely to occur in the population?
• What measures could be taken to prevent
disease occurring in the population?
• How effective are these measures?
Causality and
impact

8. Participatory epidemiology
Use participatory approaches to improve
understanding of pattern of diseases in populations
- Listen, learn, respect  researcher = facilitator
- Understanding: people make rational decisions
- Existing knowledge
- Action oriented

9. Epidemiology – why bother?
• In your current job, were there situations
where you wished to know more about
epidemiology?
– Discuss with your seat neighbor examples from
every day work

10. Surveillance
Disease data are used to assess a status compared
to a predefined threshold and to initiate defined
actions
 Information for action

11. Surveillance in Ethiopia
Write down different surveillance activities in
livestock in Ethiopia

12. Surveillance system
= composed of several surveillance system components
Export
control
Survey
Diagnostic
laboratories
Slaughter-
house
Clinical signs
Surveillance system component: „A method of surveillance that may
include one or more component activities that generates information on
the health, disease or zoonosis status of animal populations.“
OIE Terrestrial Animal Health Code 2007
Passive
Surveillance

13. • How do you normally conduct epidemiological
studies or surveillance activities?
• What are the limiting factors?

14. What is participation?
The empowerment of people to find solutions to
their own development challenges
Both an attitude and philosophy
• Learning
• Discovery
• Flexibility
A response to past failures
! Different types of participation…

15. Moving away from this…

17. 17
Participatory Epidemiology
The use of participatory rural appraisal
techniques to collect epidemiological
knowledge and intelligence

18. Applications of PE
Needs Assessments
• Priorities and entry points
Participatory Epi Research
• Basic epi studies
• Disease modelling
• Risk assessment
Participatory Disease Surveillance
• Case finding
• Disease freedom
• RP, FMD, PPR, CSF and HPAI
Impact Assessment
Strategy and Policy Reform

19. Example 1: Timeline of outbreaks
constructed by PDS teams in Egypt
ousehold
arm
ousehold
arm
ousehold
arm
ousehold
arm
ousehold
arm
ousehold
arm
ousehold
J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D
confirmed farm outbreak confirmed household outbreak
unreported farm outbreak unreported household outbreak
2006 2007 2008
Outbreaks

20. PE and PDS in Ethiopia?
For which situations/diseases would PE tools be
useful in Ethiopia?

21. Part 2-4
At the end of the PE tool sessions participants
are able to select appropriate PE tools to answer
specific research questions

22. Part 2
PE tools ranking/scoring
At the end of this session participants:
- Can apply different ranking and scoring tools
- Can explain advantages and disadvantages of
each

23. Participatory tools
- Ranking and scoring
- Informal interviewing
- Visualisation

24. Ranking and scoring
Simple ranking
The process and explanations and arguments given
for ranking are more important than the final
agreed ranks
Group work:
- What are the main reasons that make delivery of
veterinary services difficult

25. Ranking and scoring
Pairwise ranking
Allows for deeper discussions and collection of
more details
Takes more time
Group work:
- Poultry disease problems

26. Ranking and scoring
Proportional piling
Gives relative scores
Group work
- Reasons why delivery of veterinary service in
Ethiopia is difficult

27. Ranking and scoring
Matrix scoring (series of proportional piling)
To better understand
• local characterization of livestock disease
• meanings of local names

28. Part 3:
PE tools: SSI
At the end of this session participants:
• Can explain the concepts of SSI
• Can plan and conduct good interviews

29. PE tools: Semi-structured interviews
What is an interview?
Conversation between two or more people.
2 types:
• Structured
• Semi-structured
• Checklist vs. questionnaire
• Open ended questions
• Non-leading questions

30. PE tools
Semi-structured interviews
• Interviewing is a specialized skill
• Bad interviewing technique yields poor
information and may create feelings of suspicion,
fear or even hostility
• What types of questions are you familiar with?
• Advantages and disadvantages?

31. Questions
What is an open-ended question?
• questions starting with why, when, how, what,
where, who?
What are closed-ended questions?
• a question where the answer is either yes or no
What is a leading question?
• a question that includes part of the answer
within the question  people want to give the
right answer

32. Questions: closed or open ended? Neutral
or leading? Appropriate questions?
Instead of… …better to ask
Do you have goats? What animals species do you
keep?
When did you last vaccinate
against FMD?
What do you do against FMD?
Do you keep ducks or not? What types of poultry do you
keep?
Do you eat dead animals? What do you do with animals
that die due to disease?

33. Differences between questionnaires and
checklists
Questionnaire Checklist
Using a list of questions to
be followed when collecting
data
Uses bullet points of topics
to guide the facilitator in
capturing the main points
during the interview
Fixed questions - not
changeable
Questions are not fixed, can
vary depending on the
situation
Not flexible in different
situations
Flexible and suitable for all
environments
Enumerators collect
information
Facilitators collect
information

34. Example of a checklist /interview guide
Objective: identification & prioritization of animal health issues
• Introductions
• Purpose of the visit – general!
• Livestock species kept
• Husbandry systems
• Grazing locations
• Problems facing livestock keeping
• If diseases mentioned – explore further (frequency, seasonality,
morbidity mortality, what do you do?….)
• Questions from participants?
• Give advice
• Thanks

35. What to consider before going to the field?
Content
• Objective of conducting interview
• Secondary information about area
• Talk to key informant
Context:
• Time and place of interview
• Duration interview
• Understand community culture and background

36. While in the field
• Group organization (interviewer, translator,
recorder, assistants)
• Do not disclose the disease your searching.
• Apply open ended questions (where, who,
what, how, when)
• Ordering questions from general to specifics
• Probe further the area of interest

37. While interviewing
• Use simple language
• Mind the body language
• Observe for non verbal communication
• Keep eye contacts where possible
• Include everybody
• Use appropriate PE tools to bring out
information

44. Pretty, N.J., Guijt, I., Thompson, J. and Scoones, I. (1995) A Trainer’s Guide for Participatory Learning and Action, IIED.

45. Group work – semi-structured interview
Divide into 3 groups:
come up with an objective for a semi-structured
interview and a checklist to answer this objective
AFTER THAT: role play!
Select one interviewer and one notetaker – the rest
are observers (to give feedback), interview a person
from another group
2 rounds

46. Part 4: PE tools
Visualisation
At the end of this session participants
- Can explain the use of different visualization
tools
- Can apply seasonal calendar and mapping in PE
studies

47. Part 4: PE tools
Visualisation
Participatory mapping
Useful at the beginning of an inquiry to define the
spatial boundary of the system under investigation.
It also acts as a good ice-breaker as many people
can be involved
If we are interested to map livestock resources
what kinds of things could we map?

48. Map examples
Can be at different scale

50. PE tools: visualization
Seasonal calendar
• Local perception of seasonality of disease,
farming practice, risk factors, etc.
• Seasonality of rainfall and festivals

51. PE tools: visualisation
Group work 1, aim: identify possible groups for field
work
• draw map of Ethiopia
• mark the project locations
• show ways how one can move from one location
to another
• estimate of time needed to move from one
location to another
• Maps should have a title, scale and key.

52. Group work 2: use calendar to relate seasons, key
events and disease incidence
• Select an area of your choice
• Map the seasons
• Estimate occurrence of major diseases
(proportional piling)

53. Group work 3: disease transmission
- Draw transmission pathways for a disease of
your choice
- For each pathway, indicate how much men,
women and youth are involved (proportional
piling)

54. Part 5:
Planning FGD and data analysis
• Define objectives of FGD
• Target audience
• Identify PE tools, ensure gender aspects are
covered appropriately

55. Data recording
• Needs to be carefully planned in advance!
• Prepare templates
• Poor recording leads to loss of information
• At least one person recording
• Consider using voice recorder

56. Example: recording of pairwise ranking
Factors
compared
Winning factor Reason
4x7 4 The capacity also includes the data recording system
4x8 4 If capacity is built they can work even in areas where
there is no private veterinary services
4x9 4 The first thing is improving capacity, then incentives
come later
4x10 4 If vets capacity is built, then they can create farmers
awareness as much as possible
4x11 11 The poor integration with other sectors has led to capacity
limitation
5x6 6 Work burden is not such much problem here

57. Data analysis
Only possible if data was recorded consistently

58. When do we carry out analysis?
• during the interview by probing (example!)
• summarizing the interview
• summary report for the village or area
• at central level

59. Triangulation is carried out:
• between questions and tools used with the same
informants
• between questions and tools repeated with multiple
informants
• between information collected from interviews and
tools with laboratory diagnostics
• between PE findings and secondary information

60. Field recording forms
Interview records
PE field study report

61. Analysis of simple ranking data
Group 1 result:
1. cow
2. goat
3. sheep
4. donkey
5. chickens
Group 2 result:
1. cow
2. goat
3. sheep
4. chickens
5. donkeys
Group 4 result:
1. cow
2. goat
3. chickens
4. sheep
5. donkeys
Group 5 result:
1. cow
2. goat
3. sheep
4. donkey
5. chickens
Group 3 result:
1. goat
2. cow
3. sheep
4. donkeys
5. chickens

62. Summary of interview results
Interview
Species 1 2 3 4 5 Total Rank
Cow 1 1 2 1 1 6 1
Goat 2 2 1 2 2 9 2
Sheep 3 3 3 4 3 16 3
Donkey 4 5 4 5 4 22 4
Chickens 5 4 5 3 5 22 4

63. However if there were a sixth group …
Group 6 result:
1.cow,
2.goat,
3.sheep,
4.chickens,
5.ducks

64. Interview
Species 1 2 3 4 5 6 Total Rank
?
Cow 1 1 2 1 1 1 7 2?
Goat 2 2 1 2 2 2 11 3?
Sheep 3 3 3 4 3 3 19 4?
Donkey 4 5 4 5 4 - 22 5?
Chickens 5 4 5 3 5 4 26 6?
Ducks 5 5 1?
This is not correct!

65. In this case the original ranks should be converted to
scores.
For each interview the species ranked 1 is given a score
of 6, species ranked 2 is given a score of 5, 3 = 4, 4=3, 5
= 2, and 6 =1.

66. Summary of interview results
Interview
Species 1 2 3 4 5 6 Total Rank
Cow 6 6 5 6 6 6 35 1
Goat 5 5 6 5 5 5 31 2
Sheep 4 4 4 3 4 4 23 3
Donkey 3 2 3 2 3 - 13 5
Chickens 2 3 2 4 2 3 16 4
Ducks - - - - - 2 2 6

67. Analysis of proportional piling data
Interviews
Species 1 2 3 4 Median Range
Cow 50 40 45 40
Goat 20 25 20 15
Sheep 15 20 20 15
Donkey 10 10 5 10
Chickens 5 5 10 15
Ducks 0 0 0 5
100 100 100 100

68. Median
• A measure of the center of the data
• The median is the middle value of a set that has
been put into rank order
The median, like the mode, is not generally affected
by one or two extreme values (outliers) which may
greatly affect the mean (average).
Example: Cattle: 52 – 42 – 45 – 40 – 48
Put in rank order: 40 – 42 – 45 – 48 – 52
Median: 45

69. Range
A measure of the dispersion of the data
Reports from the smallest value (minimum) to the
largest (the maximum)
Example:
Cattle: 52 – 42 – 45 – 40 – 48
Range: 40 – 52

70. Analysis of proportional piling data
Interviews
Species 1 2 3 4 Median Range
Cow 50 40 45 40 42.5 40 - 50
Goat 20 25 20 15 20 15 - 25
Sheep 15 20 20 15 17.5 15 – 20
Donkey 10 10 5 10 10 5 – 10
Chickens 5 5 10 15 7.5 5 – 15
Ducks 0 0 0 5 0 0 - 5
100 100 100 100

71. E.g. Use of income resulting from livestock
sales (results from men; n=14)

72. Discussion
Compare qualitative and quantitative epidemiology
- Advantages
- Disadvantages

73. Quantitative versus Qualitative
Epidemiology
Quantitative
• Objective
• Numerical estimates
• Data intensive
• Expensive
• Logistically complex
• Long-time frames
• Difficult to sustain
• Information gaps
Qualitative
• Subjective
• Flexible
• Rapid
• Discovery
• Simple
• Sensitive
• Skilled field personnel
• Analytical challenges

74. Qualitative data checking
Probing
• Internal consistency
Triangulation
• Multiple methods and sources
• Patterns and coherence
• Understanding bias
Understanding conflict of interest
On the spot analysis
• Evolving hypotheses and data collection
• Weighing of evidence

75. Bias
What do you understand under bias?
 Systematic deviation from reality, aligning to a
certain belief, ranking people in a population, being
selective, unjust, favouring one side over another
Q. What might be sources of bias in field work?

76. Some possible biases in PE studies…
• Spatial bias
• Project bias
• Personal bias
• Seasonal bias
• Diplomatic bias
• Professional bias
Important to understand our own biases!
How can you
minimize bias?

77. Questions?

78. The presentation has a Creative Commons license. You are free to re-use or distribute this work, provided credit is given to ILRI.
better lives through livestock
ilri.org
Special thanks to Saskia Hendrickx (ILRI) and PENAPH.net for slides