e degree of association and
determination that it has with malaria, the frequency with which that
risk factor occurs in the community, and the possibility of preventing
or controlling it.

      The next task is to calculate the relative risk for each of the
risk factors that were found to be statistically significant.  As has
already been explained, the relative risk in this study is the ratio
of the risk of contracting malaria in those individuals who are exposed
to any of the risk factors studied to the risk in those who are not
exposed. 

      This ratio indicates how much greater the risk of contracting
malaria is in those who have the characteristic or risk factor than
it is in those who do not have it.

      Relative risk measures the degree of association between malaria
and each of the postulated risk factors.

      Both relative risk and attributable risk are measures of
association of the excess risk from exposure to or presence of a
specific risk factor.

      Attributable risk measures the excess risk of malaria that can
be attributed to exposure to a certain factor, for example, exposure
to housing that is not completely enclosed.

      Population attributable risk is a measure of association
influenced by the prevalence of the factor in the total population. 
Population attributable risk measures the percentage decline in the
number of cases of malaria that would occur if the causal factor were
totally eliminated or neutralized. 

      The formulas and calculations necessary for estimating relative risk
and attributable risk are the following:

RELATIVE RISK   =  Incidence in the population exposed to the factor  
Incidence in the population not exposed to the factor


ATTRIBUTABLE RISK IN  =     Incidence in the population exposed
THE POPULATION EXPOSED   -Incidence in the population not exposed     



PERCENTAGE OF               Incidence in the population exposed
ATTRIBUTABLE RISK IN  =   - Incidence in the population not exposed x 100
THE P