Evidence-Based Practice for Nurses

feelings. The VAS is a 100-mm line that is anchored on each end with words or
symbols. Subjects mark a line across the VAS to indicate the intensity of their
feelings or attitudes along the continuum represented. In nursing, VAS scales
are frequently used to collect data about pain, fatigue, quality of life, and health
status. This type of scale can be completed easily and quickly and is understood
by most people. To score the VAS, researchers measure the distance of the
mark from the end of the scale in millimeters. Usually the low end of the scale
is used as the zero point.

Physiological Measures

Physiological measures provide a wide range of biological, chemical, and
microbiological data. Measures of blood pressure, cardiac output, and weight
are examples of biological variables. Chemical measures include electrolytes,
hormones, and cholesterol, while microbiological measures include the bacte-
rial counts obtained from urine and blood cultures. There are many advantages
to using these objective measures because they tend to be accurate. Some

No pain Worst pain

Line length = 100 mm

FIGURE 10-3 Example of a VAS to Measure Pain

When several Likert scales are used in a question-

naire, the positive numbers or indicators should

consistently be in the same position, for example

1 = strongly disagree, 2 = disagree, 3 = neutral,

4 = agree, 5 = strongly agree.

FIGURE 10-2 Example of Likert-Type Scale

KEY TERM

physiological

measures: Data

obtained from

biological, chemical,

and microbiological

phenomena

A nurse researcher is interested in testing an intervention on the quality of life of individuals

with lung cancer. What methods do you think the nurse researcher should use to collect data?

CRITICAL THINKING EXERCISE 10-1

10.2 Collecting Quantitative Data 259