QA and QC Flashcards
(50 cards)
What are pre-analytical errors
errors that affect specimens before the tests are performed
What analytes are effected by circadian and diurnal variation
electrolytes, glucose, urea, creatinine, uric acid, iron, cholesterol, albumin, total protein, AST, ALT and LD
What variables cause modifiable pre-analytical errors
circadian variation, menstrual cycle, fasting, alcohol, smoking, dietary supplements and drugs
What analytes are effected by eating before collection
glucose, GH, insulin, ionized calcium, triglycerides, total lipids, iron and LD are made higher
chloride, potassium and phosphate are lowered
What tests are effected by the ingestion of alcohol
blood glucose, GGT, lactate concentrations
What tests are effected by smoking tobacco
ammonia, blood gases, glucose and immunoglobulins
What is increased when collecting below an intravenous line
potassium and glucose
What tests are effected in ambulatory patients
albumin, calcium, lipoproteins, cholesterol, thyroxine, ALT, AST, amylase, and immunoglobulins A, G and M
What are the effects of prolonged venous occlusion
increased total protein, total lipids, iron, cholesterol, AST, and bilirubin
decreased potassium
What are the effects of fist pumping
accumulation of potassium, phosphate, lactate causing decreased blood pH and increased ionized calcium
What effects does hemolysis cause
increased LDH, potassium, magnesium, phosphate, asparate aminotransferase, total protein and ammonia
positive interference in cholesterol, triglyceride and creatine kinase assaus
negative interference in bilirubin, albumin and carotene assays
What specimens are photosensitive
serum bilirubin, carotene, methotrexate and urine bilirubin, urobilinogen and porphyrin
What specimens are temperature sensitive
ammonia, lactate and blood gases
What are delta checks
they can detect preanalytical errors comparing current value to previous values
Define accuracy
an estimate of non-random systematic error between samples of data. The agreement between the mean estimate of a quantity and its true value
Define central tendency
the value about which a population is centred. The mean, median and mode are all used to describe the central tendancy
Define coefficient of variance
a statistic that measures the distribution of data about the linear regression line
Define error
the difference between a single estimate of a quantity and its true value
Define mean
the arithmetic average of a data set
Define median
a middle value of the population
Define mode
the value of a population that occurs in the greatest frequency
Define precision
a descriptor of random variation in a population of data
Define proportional systematic error
an error that is always in one direction, the magnitude of which is a percentage of the concentration of the analyte
Define random analytical error
an error that cannot be predicted
