Psychometric validation is the term that psychologists give
to defining the perfomance characteristics of a measurement.
The methods used to evaluate the qualities of a test can be
used in a wide variety of circumstances, including for
defining the measurement properties of a questionnaire used
to capture patient outcomes.
By evaluating the different operating characteristics of a
questionnaire you will have the information that is
necessary to determine if the questionnaire is appropriate to answer you research questions.
You will also have the information necessary to estimate the
size of the study required to detect the change that you
expect.
Required
Performance Characteristics
-
Reliability
- test-retest
reliability
-
Validity
-
content validity
- construct
validity
- internal consistency
-
Responsiveness
-ability to detect meaningful change
-
Conditions of use
- specification of
target audience
Key Points in Evaluating a Questionnaire
-
What is the intended
use of the questionnaire
-
measure change over time
-
discriminate among different groups
-
diagnose diseased individuals
-
What are the characteristics of
the individuals who will complete the questionnaire
(age, disease-specific or general population, gender,
one language and cultural or international use where
data will be pooled)
-
Many performance characteristics
can be defined outside of a clinical trial