How To... - Interpret Data
What health indicators are public health problems?
To identify health problems in your program:
Examine the prevalence of the health indicators
of your population included in the PedNSS and PNSS tables by looking at the Summary of Health
Indicator Tables (PedNSS Table 2C and PNSS Table 2C) that describe
the overall prevalence of all health indicators collected by these systems.
Compare the prevalence of your health indicators to other populations
within PedNSS and PNSS as well as to the general population prevalences or
Healthy People 2010 objectives to determine if the specific health
indicators are health problems.
Definition: Prevalence indicates the proportion of individuals
in a population with a given health indicator at a given time or over a
specified period of time. For more, see
Comparison of PedNSS and PNSS Data to Other Data
Although the PedNSS and PNSS data are predominately from
low-income women, infants, and children participating in public health
programs, it is appropriate to compare the PedNSS or PNSS prevalence of
health indicators to national health objectives, other surveys, or
surveillance systems of the U.S. population of women, infants, and
children to identify public health problems.
Data that can be used for comparison include:
The Healthy People 2010 objectives,
Reference population expected rates,
U.S. population-based surveys such as the National Health and Nutrition
Examination Survey (NHANES).
A discussion of each of these data sources follows.
Examples of Data to Use for Comparison
Healthy People 2010 Objectives
Healthy People 2010 objectives were designed to serve as goals for
monitoring progress towards improving the health status of the nation.
Although, the 2010 Objectives were established for the general population,
they are also appropriate for the low-income populations included in PedNSS and PNSS. In fact, some objectives are specific to low income
population groups. Additionally, several Healthy People 2010 objectives
can be monitored using PedNSS and PNSS.
Reference Population Expected Rates
A reference population is the standard against which a population that is
being studied can be compared. Reference populations were used to develop
two common screening tools in the United States:
These screening tools are not only used to determine an individual's risk
for a health problem but they are also used to determine if a population
has a greater prevalence of a health indicator than expected when compared
to the reference population, often referred to as the reference population
U.S. Population Surveys and Surveillance
Data from surveys, such as NHANES, are representative of the U.S.
population and can be used for comparing the program-based data from
PedNSS and PNSS, as long as the differences in the populations that each
represent are understood.
The primary difference between U.S. population-based surveys or
surveillance systems and the PedNSS and PNSS are as follows:
- PedNSS and PNSS were not developed to provide data representative of the
general population of women and children in the state, but rather to
provide information about the women and children served by public health
- PedNSS and PNSS are referred to as program-based surveillance systems
because they are based on data routinely collected for women and children
participating in public health programs serving low income populations.
- These data are not representative of all low income women and children
in the country or in a state. However, the PedNSS and PNSS are
representative of the population served by the state WIC program when all
WIC clinics in a state collect PedNSS and PNSS data. This surveillance
information is used for planning and evaluating the public health program.
Comparisons of Populations Within PedNSS and PNSS
PedNSS and PNSS data can be used to make comparisons among participating
public health programs within each surveillance system.
- One geographic area can be compared to a larger geographic area to which
it belongs, for example state to nation or county to state.
- Comparisons of populations within PedNSS and PNSS can be made from one
geographic area to another geographic area such as one state to the
neighboring states or one county to another county.
For each health indicator, several comparisons of prevalence data can be
made using the PedNSS and PNSS tables.
- The Summary of Health Indicators tables can be used to examine the
overall prevalence. These tables also can be used to compare the prevalence of a
health indicator of one geographic area to another within the state,
between states, or between the state and the nation.
- The Health Indicator by Demographic Variables tables can be used to
determine if the prevalence of a health indicator differs by age,
race/ethnic, and education groups. These tables provide age, race/ethnic,
or education specific prevalence for a health indicator and can also be used to
compare one geographic area to another within the state, between states,
or between the state and the nation.
- The Summary of Demographic Indicators tables can be used in conjunction
with Summary of Health Indicators tables to determine if the age,
race/ethnic, or education distributions are similar or different when
comparing one geographic area to another.
- When one specific demographic characteristic (age, race/ethnic, or
education) is very different in one population compared to another, the
prevalence of the health indicator can be affected. For example, if the
prevalence of overweight in your state is the same as the national
PedNSS prevalence, yet, the national PedNSS has a much higher proportion
of Hispanic children you may want to conduct an additional analysis to
determine if the differences in distribution of Hispanic children
affected the prevalence of overweight. Standardization is a technique
used to make the populations more comparable for a specific demographic
characteristic thus, making the prevalence of the health indicator of
interest also comparable.
Learn how to calculate standardized rates using
an example of standardization of state prevalence to national race/ethnic
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Page last reviewed: October 29, 2009
Page last updated: October 29, 2009
Content Source: Division of Nutrition, Physical Activity and Obesity,
National Center for Chronic Disease
Prevention and Health Promotion