Page 495 - Encyclopedia of Nursing Research

462 n SeCOnDARy DATA AnAlySIS

Secondary information is an inexpensive The question of using clinical nursing
data source that facilitates the research pro- data sets for secondary analysis comes with
S cess in several ways. It is also useful for gen- the advent of clinical nursing information
erating hypotheses for further research. It is systems. The use of clinical databases as
useful in comparing findings from different research data sets must be examined care-
studies and examining trends. population fully. One difficulty is that restricted data
data sets, such as Bureau of the Census data, resources force clinicians to choose carefully
may be used to compare sample with pop- which data to collect. These data are usually
ulation characteristics to examine the repre- not identical with what the researcher needs.
sentativeness of the study sample. Beyond data restrictions, another major
The analysis of secondary information difficulty is that the sample biases of clinical
is a useful strategy for learning the research databases and research data sets for random-
process. The secondary data sets that have ized control studies are different. This differ-
used optimum sampling techniques provide ence in bias of the data from clinical databases
an optimum resource for students by virtue and randomized controlled trial research
of the quality of sampling and the time and data sets can be exploited as a strategy for
expense involved in data collection. given doing cross-design synthesis. however, this
that students are expected to understand, to special case aside, the issue is that of sam-
explain, and to defend the data set in terms ple representativeness. The research sample
of purpose, sample selection, methods, and is selected for a specific reason, with specific
instruments, only the real-life collection and delimitations in mind, to be representative
recording of data remain are not experienced of the general population. In contrast, the
by the student. Another advantage of using clinical population from which the clinical
secondary data analyses while learning to do data set is drawn is representative only of
research is that it protects the pool of poten- that type of patient or client on whom data
tial research participants and agencies for is being collected in that location and rarely,
participation in studies conducted by quali- if ever, typical of the general population or
fied researchers. even all persons with that clinical problem.
every research study is conducted with For example, patients with congestive heart
a specific purpose in mind. Delimitations are failure in Alabama are not necessarily rep-
specific to the original study and introduce resentative of patients with congestive heart
specific types of sampling and other bias failure in new england or California. The
into the original study. Operational defini- same is true of patients with congestive heart
tions may not be replicable in a second study. failure in a community hospital versus those
For learning purposes, differences in the in a teaching hospital in the same county.
original study and data set can be handled These caveats necessitate close evalu-
through careful critique processes by stu- ation of data sets to be used for secondary
dents. however, the biases and differences analysis. The information needed for such
that exist may be too extreme to permit a evaluation must be archived along with the
valid secondary analysis outside the practice data set. Such information includes study
situation. purpose; data collection details, such as
Archived data sets are rarely held in the who collected the data, when, and where;
form of raw data because the data are usu- sampling criteria and delimitations; known
ally summarized. The summarization may biases; operational definitions; and methods
or may not be appropriate for the research of data collection.
question under consideration for secondary Traditionally, nursing has not archived
analysis. To analyze such data further con- research data sets of its own for use in teach-
founds results beyond acceptable limits. ing or secondary analysis. nursing students