Behavioural Surveillance Surveys - The Wisdom of Whores

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Once data have been collected, they must be analyzed to calculate
chosen indicators, to assess changes in indicators over time, and to explore
relationships between variables. The probability sampling methods explained
in Chapter 4 produce representative and replicable samples, and they also
permit us to use statistical methods for analysis so that the statistical significance
and accuracy of the data can be assessed.
Analysis and
Interpretation of Results
This chapter presents recommended
methods of statistical analysis of data from
repeated surveys of HIV-related risk behaviors.
It describes which statistical tests are most
appropriate in different settings, and gives
formulas and worked examples for the most
common tests. Interpretation of statistical
analyses is discussed, and common sources of
bias in the data are outlined.
There are numerous existing statistical
analysis computer packages such as Epi-Info,
SPSS, SAS, and STATA which can be used to
analyze behavioral data. These packages ease
the analysis process by conducting statistical
tests using standardized formulas. However,
they should be used by researchers who fully
understand these tests and their assumptions
and limitations. The discussion below provides
some basic information regarding these
statistical tests. For explanatory purposes,
some hand calculations of these statistical tests
are provided in Appendix 5.
B EHAV I OR A L S U R V EI L L A NC E SURV EY S CHAPTER 7
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