Page 443 - Encyclopedia of Nursing Research

410 n POPUlATIONS AND AGGReGATeS

monitoring, and improvement. Population facts about a sample drawn from that pop-
health research can be used to describe, to ulation or universe” (p. 89). In statistics, pop-
P explain, to predict, and to control. Keys for ulation characteristics are called parameters
effective study of the determinants of health and are denoted by Greek letters, and sample
include a conceptual framework and health characteristics, called statistics, are denoted
indicators that are valid, sensitive, specific, by Roman letters. According to Blalock, in
feasible, reliable, sustainable, understandable, inductive statistics “it is the population,
timely, comparable, and flexible. These keys rather than any particular sample, in which
are essential to accomplishing the ultimate we are really interested.” As a matter of con-
goal of population health research, which venience, a sample is selected but the goal is
is to translate knowledge gained from the “practically always to make inferences about
results of population health studies into pol- various population parameters on the basis
icy that can be used to prevent disease and of known, but intrinsically unimportant sam-
promote health. ple statistics” (p. 90). The underlying founda-
tion for making inferences from samples to
Sandra C. Garmon Bibb the population is the mathematical theory of
probability.
Within the health field, particularly in
public health and the disciplines of epidemi-
PoPulations anD ology and biostatistics, and the nursing spe-
cialization of public health nursing, the term
aggregates population usually refers to biological enti-
ties such as people, animals, or microorgan-
isms that hold characteristics in common.
The term population has come into the lan- Population has a very prominent position
guage of nursing by way of public health spe- in epidemiology. In discussing the classical
cialists and statisticians. It has importance understanding of epidemiology, J. N. Morris
because of its meaning to both researchers (1964) referred to it as “the study of the health
and practitioners. In a very broad sense, the and disease of populations” (p. 4). More
term population refers to a collection of enti- recently, Mausner and Kramer (1985) defined
ties that have one or more characteristics in epidemiology as “the study of the distribu-
common. The characteristic may be defined tion and determinants of diseases and inju-
in many ways, in terms of place, time, or a ries in human populations” (p. 1).
personal characteristic. According to Kendall Historically, public health specialists
and Buckland (1960), “in statistical usage the such as health officers focused on popula-
term ‘population’ is applied to any infinite tions and subpopulations as the target for
collection of individuals. It has displaced planning, service programming, and evalu-
the older term ‘universe’ … it is practically ation efforts. Although public health nurses
synonymous with ‘aggregate’ and does provided clinical services in public health
not necessarily refer to a collection of liv- programs directed to target populations such
ing organisms” (p. 223). The conception of as children younger than 6 years or prenatal
a population is basic to an understanding clients, their predominant focus was clini-
of inductive or inferential statistics. Stated cal, at the level of the patient or the family.
succinctly by Blalock (1960), “the purpose The idea of taking a population approach to
of statistical generalizations is to say some- the practice of public health nursing began
thing about various characteristics of the to appear in public health nursing discus-
populations studied on the basis of known sions and literature in the 1970s. In a 1977