Transcript Rapid Community Needs Assessment

Public Health CBRN course
Rapid Community Needs
Assessment
Bonnie Henry, MD, FRCPC
Goals of Session
To learn the principles of rapid
community risk assessment using
modified cluster sampling methods
 To understand when this technique
may be useful in response or
recovery from a disaster

Goals of Rapid Needs Assessment
To rapidly obtain population-based
estimates of need in the early
aftermath of a disaster
 Should also be a way of reaching the
affected areas with information about
relief efforts and services

History

Based on methods developed by the WHO
for estimating immunization coverage in
the EPI program
 Used to estimate community impact of
Hurricane Andrew in South Florida in 1992
 Also used after the Sept 11, 2001 attacks
in NYC to assess needs in residents of
Lower Manhattan
Who would use the data
Government organizations
 Disaster relief organizations (Red
Cross etc)
 Provincial, regional and local public
health and healthcare organizations
 Law enforcement
 Utilities, (especially electricity, water)
 Media, etc.

Cluster Sampling Methods
 Systematic sampling
of 30 ‘clusters’
 Create a grid over the
area to be sampled
– ¼ mile squares on
street map
 Assign each square or
‘cluster’ a number
Cluster Sampling Methods
 Determine the interval you need to end up
with 30 clusters to sample
– For example if you have 120 squares in your
grid you will have an interval of 4 (120/30=4)
 Randomly determine where to start
– In this case pick a number between 1 and 4
– You can use a random number generator or
the serial number on a $5 bill
 Select your 30 clusters
Cluster Sampling Methods
 Go to the centre of the first cluster (i.e.
square or cluster 3 on your map)
 Determine your sampling unit
– Usually people or households
 Determine the number of units to be
sampled in each cluster (i.e. 10
households)
 Proceed in a randomly picked direction to
the first occupied household
Cluster Sampling Methods

Interview the first adult at the occupied
residence
 Then go consecutively to the next
occupied household until you have
reached 10 in that cluster
 If a multi-unit dwelling or apartment
building pick first occupied unit for
interview
 Move on to next selected cluster
Example: Systematic sampling
Source: D. Coulombier, Epicentre
Source: MSF
Sampling methods – organization of sampling units; Cegrane
camp, Cegrane, Macedonia - 1999
Source; B. Woodruff, US-CDC
Sampling interval = 12; Starting number = 3; Cycle = 3
1
2
19
37
3
4
20 21 22
38 39 ....
Source: EPIET
5
6
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10
23 24 25 26 27 28
11 12
29 30
13
31
14 15
32 33
16
34
17 18
35 36
Interview Methods
 Interview team usually 3-4 people
including an epidemiologist and volunteer
interviewers
– from medical schools, public health staff etc.
 Use a simple questionnaire
 Ensure team able to provide information
on:
– Location of medical treatment, supply
distribution sites
– Provide preventive health messages on food,
water safety, handwashing, injury prevention
etc.
Sample Questions

How many and what percentage of surveyed
households reported the following?
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–
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–
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–
–
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–
–
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Not enough food
No running water
No electricity
No heat/air conditioning (in temperature extremes)
No functioning toilet
No telephone
No car or truck
Injured resident(s)
Ill resident(s)
Resident(s) in need of medical care
Resident(s) unable to obtain needed medications
Resident(s) in need of counseling
Resident(s) with special needs
Displaced from home
Time frame for initiating study
After ground transportation is
restored
 Approximately 3 and 10 days after
the event for severely affected areas
 Assessments of less severely
affected areas phased in as possible

Benefits
 Practical and standardized methods allow
for rational assessment (not based on
rumours only)
 Gives a picture of what needs are and
helps direct relief operations
– E.g. switch from mass casualty trauma
services to primary care and preventive
services
 Can monitor over time
“Being roughly right is generally
more useful than being precisely
wrong”
Guha-Sapir, D. Rapid assessment of health needs in mass emergencies:
Review of current concepts and methods. World Health Stat Q. 1991;44:171-181.