Concepts of Measurement: Validity & Reliability Flashcards
Reliability
Does it measure something consistently?
Reliability
How do I know that the test, the scale, the instrument works every time I use it?
Reliability
Represents the consistency of measure obtained
Validity
Does it measure what it is supposed to?
Validity
How do I know that the test, scale or instrument I use measures what it is supposed to?
Validity
The extent to which an instrument reflects the true measure being observed (accuracy)
Error in Physiological Assessment
Environment, User, Subject, Machine, Interpretation
Error in Physiological Assessment - Environment
Temperature - can affect the validity of the reading
Error in Physiological Assessment - User
A procedural error or interrater reliability
Error in Physiological Assessment - Subject
Needs to correlate to what the patient is feeling. If a patient is feeling anxious when having their BP taken their heart rate will automatically increase. This will affect the validity of their measurements.
Error in Physiological Assessment - Machine
Accuracy, Selectivity, Precision, Sensitivity
Error in Physiological Assessment - Subject
Patient or phenomena
Accuracy
Is the machine giving the result it should provide - is it reliable? Is it valid?
Selectivity
Is the correct equipment being used? The machinery is intended for a specific type of finding.
Precision
It provides results that are reliable and valid
Sensitivity
That the machine can pick up the deterioration of the patient, provides the actual reading, alerts of any alterations within findings.
Interpretation
How are the results interpreted? The nurse needs to have the right understanding and knowledge of the findings attained.
Impact of the environment on equipment validity and reliability
If the patient has cold clammy hands, this may not provide an accurate reading. This also includes if the fingers are moving and don’t remain still.
BP Validation
Checking that the pressure gauge of the monitor against a reference number
BP Calibration
The process of comparing the pressure gauge against a known accurate reference, and adjusting the pressure to have the same readings.
