Evidence-Based Practice for Nurses

Epidemiologic principles provide the foundation for public health and are

useful for supporting evidence-based practice. Principles of epidemiology are

used to determine the effect and extent of disease in a population. Knowing

these determinations is important for decision making regarding prevention,

treatment, control, and research of disease in populations. Epidemiology is used

to describe the natural history of disease and to identify the etiology, or cause

of disease. Epidemiology is used in surveillance of disease. Disease surveillance

is used to monitor the distribution of disease and evaluate the effectiveness of

prevention and control programs.

There are two types of epidemiologic investigations: descriptive and analytic.

Descriptive epidemiology examines the distribution of disease in a population

in terms of person, place, and time. The purpose of descriptive epidemiology

is to identify subgroups that may have the highest risk of disease or the out-

come of interest. Epidemiologists also use this approach to find clues about the

potential causes of disease and to generate hypotheses about the relationship

between exposures and outcomes. Analytic epidemiology is used to investigate

the determinants of disease. Differing from descriptive epidemiology, analytic

epidemiology is hypothesis testing and is used to determine the etiology of

disease or health-related outcomes. Special types of statistics are used to de-

termine associations among determinants of disease.

Epidemiology is an exciting field by which nurses use CSI-like skills to inves-

tigate patterns of disease to best determine contributing factors with the goal

of improving health outcomes. For example, a nurse in the pediatric intensive

care unit might ask, “What factors are contributing to the increase in gunshot

wounds in September as compared to March?” A family nurse practitioner might

ask, “Why are more children affected by asthma in one county as compared

with children in a neighboring county?” A nurse scientist might ask, “Why are

women who cook over open flames more at risk for upper respiratory infections

as compared to women who cook with gas or electricity?” By understanding

findings from epidemiologic studies that result from questions such as these,

nurses can identify strategies to improve health outcomes. Nurses can then

implement various strategies to determine best practice.

KEY TERMS

epidemiology: The

study of distribution

and determinants

of disease in human

populations

distribution: The

pattern of disease

occurrence in and

among populations

or subgroups

determinants:

Factors that are

capable of bringing

a change in health

etiology: The cause

of disease

descriptive

epidemiology:

Examination of

the distribution

of disease in a

population in terms

of person, place,

and time

analytic

epidemiology:

Investigation of the

determinants of

disease

Indicate whether the following statements are true or false:

1. Epidemiology is the study of disease in populations rather than in individuals.


2. Descriptive epidemiology is used to investigate the determinants of disease.

TEST YOUR KNOWLEDGE 8-1

How did you do? 1. T; 2. F

194 CHAPTER 8 Epidemiologic Designs: Using Data to Understand Populations