|THE USE OF SCREENING TOOLS FOR THE ESTIMATION OF
TUBERCULOSIS CASE RATES IN A COMMUNITY
|AK Chakraborty: Indian J Public Health 1980, 24,
The problem in using simple tools e.g. chest symptoms
for epidemiological surveys, designed to quantify the problem is
that estimates from these simple surveys are considerable underestimates.
Recent research has, however, paved the way for the use of these
simpler tools for use in estimating tuberculosis case prevalence
rates in the community. A tool which is simple, convenient to use
and maintain, cheap but highly sensitive is called "screening
tool". Such tools are used for making initial selection of
the given population. Tuberculin test, X-ray & symptom elicitation
are the main screening tools used for epidemiological surveys and
TB Control Programme. In the programme, symptom elicitation and
X-ray examination are the screening tools of choice for Case-finding.
In the survey, tuberculin and X-ray are the only two tools used,
although tuberculin is not a good screening tool (40% population
infected). Use of symptom screening in surveys, however, is restricted
in the absence of adequate information on comparison of prevalence
rates obtained by this method of screening with the best estimate.
The performance of symptom screening with either culture or smear
microscopy have been attempted. They showed that by applying suitable
correction factors they may be rendered comparable to the best estimate.
The symptoms may be useful in the survey as a screening tool and
may give the rates as proximate to the true rates as possible. They
will enable considerable simplification of epidemiological studies
in tuberculosis without compromising on the precision of the estimates
|KEY WORDS: SCREENING TOOLS, ESTIMATES, CASE
RATE, SYMPTOMS, X-RAY, TUBERCULIN, SURVEY.