Behavioural Surveillance Surveys - The Wisdom of Whores

What is to be measured ?
Indicators must be chosen before the
survey process begins, so that questionnaires
can be checked to see that they do indeed
yield information that can be used to construct
the indicators selected. Standardized
indicators have been defined for several
sub-populations likely to be included in BSS.
It is recommended that standardized indicators
be used wherever possible. The use of
standard definitions and time reference
periods greatly increases the comparability of
data across time and in different populations,
and increases the cohesion of a national
surveillance and monitoring and evaluation
system for HIV.
Detailed definitions and explanations of
standard indicators can be found in Chapter 9
of these guidelines. There may, however, be
good reasons to include other indicators that
are more situation-specific. This may be linked
to behavioral patterns in a particular culture,
or may be derived from some aspect of the
national response. Use of a particular brand
of socially-marketed condom may be an
example. Survey designers must always bear
in mind, however, that BSS is not able to
evaluate the independent effects of individual
prevention projects.
Step 5 : operationalizing
definitions of populations of
interest
Once overall respondent groups have
been settled on, the sampling universe must
be defined. The universe is the population to
which results may be extrapolated. An example
of a respondent group might be sex workers,
and the sampling universe could be those
selling sex in the capital city of the country.
After defining the sampling universe,
the sampling domains must be identified.
A sampling domain is a specific population
segment or subset for which separate survey
estimates are desired. For example, sex
workers may be broken down into brothelbased
and freelance sex workers. Further,
brothel-based sex workers may be broken
down into urban and rural brothel-based sex
workers. In order to ensure that statistically
significant changes can be monitored over
time in particular sub-groups (or domains),
sample sizes are calculated per domain.
This means that it is very important to think
clearly beforehand one word about what
information the program really needs to
improve its prevention efforts. It is no good
calculating a sample size for all sex workers,
and then deciding afterwards that it would be
interesting to know whether changes have
occurred just in sex workers aged under 25.
Unless this is taken into account at the design
stage, it is very likely that the sample size will
be too small to calculate significant changes
in a subset of the group, such as younger
women only.
Operational definitions of survey domains
After deciding which groups and sub-groups
are of interest, survey designers must specify
exactly how they define a member of those
groups. The importance of clear operational
definitions of survey domains cannot be
over-emphasized ; it is often quite difficult to
achieve. In a culture with no overtly “gay”
identity, for example, how should men who
have sex with men be defined ? Where large
numbers of women supplement their income
with the occasional sale of sex, what constitutes
a sex worker ? Unless domains can be defined
in terms that are operationally useful for
sampling and fieldwork purposes, survey
estimates regarding such group’s behaviors
can be expected to be subject to considerable
error, and the group may have to be dropped
from BSS.
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C H A PTER 2 B EHAV I OR A L S U R V EI L L A NC E S U R V EY S