Reference Intervals in Lab Results

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Which of the following is a factor to consider when evaluating the plausibility of lab results?

Physiological possibility (correct)

Analytical precision

Reference intervals

Population overlap

What is the percentage likelihood of a healthy patient sitting outside a three standard deviation limit?

0.26%

0.13% (correct)

3.51%

0.003%

When can using an analyser with poor precision be problematic?

When the cut-off value is low

When there is a large differentiation between two populations

When the reference interval is narrow

When there is a small differentiation between two populations (correct)

Which of the following factors can affect lab results?

Haemolysis, icterus, and lipemia Signup and view all the answers

What is a common recommendation for determining the reference interval for enzyme activities?

Multiples of the upper limit Signup and view all the answers

Why is it important to consider sensitivity and specificity when using diagnostic cut-offs?

To avoid false positives and false negatives Signup and view all the answers

Which of the following is true about the ideal reference interval generation?

It is based on a large group of clinically normal animals Signup and view all the answers

What is the definition of a reference interval?

The range of values that includes 95% of the healthy population Signup and view all the answers

How are abnormal results in profiles defined?

Results that sit outside of the reference interval Signup and view all the answers

What percentage of the healthy population have abnormal results?

5% Signup and view all the answers

What is the meaning of results slightly outside of the reference interval?

They could represent the small percentage of healthy animals Signup and view all the answers

What are the yellow lines in the normal distribution graph?

A single deviation from the mean Signup and view all the answers

What is the chance of getting just one result outside of the reference interval in a panel of 15 tests?

More than half of healthy animals will have one or more slightly abnormal results Signup and view all the answers

What is the statistical definition of the reference intervals?

Mean plus 2 standard deviations for normal distribution, 2.5th to 97.5th percentile for skewed distribution Signup and view all the answers

According to the text, what are the two routes to profile interpretation?

Step-by-step and pattern match Signup and view all the answers

What is the purpose of constructing a differential list for each abnormality in the step-by-step method?

To narrow down the list of potential causes Signup and view all the answers

What is the recommended approach to reviewing the results initially?

Review the results as if you haven't seen the case Signup and view all the answers

What is the significance of normal results in profile interpretation?

They rule out many possible causes of presentation Signup and view all the answers

What is the purpose of dividing the profile into sensible groups of tests?

To categorize the tests for easier interpretation Signup and view all the answers

What is the value of normal results in profile interpretation?

They help rule out many possible causes of presentation Signup and view all the answers

What should be considered when trying to explain the findings in profile interpretation?

The presence of comorbidities Signup and view all the answers