Urinalysis Flashcards
ASCP (19 cards)
Define Pre-examination and list some examples
anything that can occur prior to when the specimen is delivered to the lab
-patient prep
- specimen collection
- handling and storage
- ordering
- educate personnel
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Define Examination and give some examples
anything that occurs during testing in the lab
- instrumentation and equipment
- reagents
- proficiency testing
Define Post-examination and give some examples
process that affects reporting of results and correct interpretation of data
- reports
- result errors
Describe proficiency testing
- CAP and API are agencies that send samples with known results
- Techs treat specimen like patient specimen
- Results are returned to the agency and compared against other labs
Define Quality Control (QC)
- Materials, procedures, and techniques that monitor accuracy, precision, and reliability
- Performed to ensure the acceptable standards are met during the process of patient testing
Define accuracy
closeness of the measured results to the true value
Define precision
reproducibility of test results
Define reliability
ability to maintain both precision and accuracy
When should QC be ran?
- Scheduled time
- changing reagent
- instrument malfunction
- results are questioned by health-care provider
Describe External Quality Control
- used to verify accuracy and precision of test
- 2 control levels required
- Data obtained from repeated measurement then lab establishes value for each analyte, then calculate mean and Standard Deviations
Define control mean
average of all data points
Define Standard Deviation (SD)
a measurement statistic that describes the average distance between each data point in a in a normal distribution is from the mean
Define Coefficient of Variation (CV)
- SD expressed at a percentage of the mean
- indicates whether the distribution of values about the mean is a narrow vs. broad range and should be <5%
Define confidence interval
limits between which the specificized proportion or percentage of results will lie
How are control ranges determined?
- by setting confidence limits that are with in +/- 2SD and +/- 3SD of the mean which indicates 95.5% to 99.7% of values are expected to within to be within range
Define trend
gradual changing in the mean in one direction
- indicates issues with accuracy
Define shift
- abrupt change in mean
- indicates issues with accuracy
What indicates issues with precision?
shown by large amount of scatter about the mean and uneven distribution above and below the mean that are most often caused errors in technique
