01 RODRIGUEZ_INTRODUCTION Flashcards
basic science that utilizes the specialty of chemistry to study human beings in various stages of health and disease
Clinical Chemistry
an applied science when analyses are performed on body fluids or tissue specimens to provide important information for the diagnosis of treatment or disease
Clinical Chemistry
units of measurement may either be:
conventional or systeme internationale (SI) unit
unit of measure consisting of seven independent base units, and each unit is represented by a symbol
SI unit
unit of measure used because compounds react on a molar basis, and expression of amounts of substances in such terms allows for a better understanding of the relative proportion of compounds
SI unit
three classes of SI units:
base, derived, and SI units
seven base SI units
meter (m) kilogram (kg) second (s) mole (Mol) Ampere (A) Kelvin (K) Candela (cd)
unit of measurement recommended because compounds react on a molar basis, and expression of the concentration following that unit of measurement allows for a better understanding of the relative proportion of compounds, hence, it has been recommended that analytes be reported using moles of solute/volume of solution (mmol/L)
SI unit
enzymatic activity is measured using what unit
international unit per liter (IU/L or U/L) or katal unit per liter (KU/L)
T/F:
pH scale is retained for measurement of hydrogen ion concentrations
TRUE
reference volume under systeme international
Liter
Base SI Unit:
length
meter (m)
Base SI Unit:
mass
kilogram (kg)
Base SI Unit:
time
second (s)
Base SI Unit:
quantity of substance
mole (mol)
Base SI Unit:
electric current
Ampere (A)
Base SI Unit:
thermodynamic temperature
Kelvin (K)
Base SI Unit:
luminous intensity
Candela (cd)
system of ensuring accuracy and precision in the laboratory by including quality control reagents in every series of measurements.
Quality control
process of ensuring that analytical results are correct by testing known samples that resemble patient samples.
Quality control
involves the process of monitoring the characteristics of the analytical processes and detects analytical errors during testing, and ultimately prevent the reporting of inaccurate patient test results.
Quality control
ability of an analytical method to measure the smallest concentration of the analyte of interest
Sensitivity
ability of an analytical method to measure only the analyte of interest.
Specificity
nearness of closeness of the assayed value to the true or target value
Accuracy
Accuracy is estimated using 3 types of studies namely:
recovery
interference
patient sample comparison
type of study that determines how much of the analyte can be identified in the sample
recovery
type of study that determines if specific compounds affect laboratory tests like hemolysis, turbidity, and icteric
Interference
type of study that is used to assess presence of error (inaccuracy) in actual patient sample
patient sample comparison
ability of an analytical method to give repeated results on the same sample that agree with one another
Precision
degree by which a method is easily repeated
Practicability
ability of an analytical method to maintain accuracy and precision over an extended period of time during which equipment, reagents and personnel may change
Reliability
ability of the analytical method to detect the proportion of individuals with the disease.
Diagnostic sensitivity
indicates the ability of the test to generate more true-positive and fewer false-negative
Diagnostic sensitivity
T/F:
Screening tests require high sensitivity so that no case is missed.
TRUE
Sensitivity (%) formula:
[100 x number of diseased individuals with a positive test] / total number of diseased individuals tested
Specificity (%) formula:
[100 x number of individuals without disease with a negative test] / total number of individuals tested without the disease
ability of the analytical method to detect the proportion of individuals without the disease
Diagnostic specificity
reflects the ability of the method to detect true-negatives with very few false-positives
Diagnostic specificity
T/F:
Confirmatory tests require higher sensitivity than specificity.
FALSE
:Confirmatory tests require higher specificity to be certain of the diagnosis
T/F:
100% sensitivity and specificity indicate that the test or method detects every patient with the disease and that the test is negative for every patient without the disease
TRUE
