بسم الله الرحمن الرحيم
Correctness and reliability of test and for calibration effected by:
Human factors < accumulation and environmental condition tested and calibration methods and method validation equipment measuring tractability sampling and the handling of test and calibration items.
These factors will effect the uncertainty measurement.
The lab should take account of these factors:-
1- When developing test and calibration method and procedures.
2- In training and qualification of personnel.
3- In selection of lab quip
Lab staff should be qualified and competent, staff under going training should supervised.
Qualification means appropriate education training, experiment and skill.
Maintain werrent job description for lab, managerial, technical and key support personnel
Equipment should be calibrated before being put into service program and procedure for calibration of equipment should be stable. Any equipment calibration should be refit after suitable duration. Must be reading any roster appendage with equipment before using.
With lab is used auto analytical or semi analytical equipment it software should capable of achieving accuracy calibration or check calibration program before use.
With the lab is use manual should be positive electricity is stable and selection the suitable filter with examination and internal the mometer temperature to keeping reagents and samples.
Pipettes should be calibration by stable procedure and materials in suitable duration (week or month).
3- external quality control( EQC) and internal quality control (IQC):
Quality control is process for assessing the accuracy and reliability of test result and used to monitor the analytical method is asset of istuctions which describes the procedure, material and equipment measuring to obtain the result) and detection of any deviation ( accuracy precision error )during the analysis.
Quality control may be internal(IQC) or external (EQC)
EQC used to detect hidden problems ,to compare our performance with other improve quality and this type of quality control can be locally , natural or international .
IQC Internal quality control
Set of procedures undertaken by laboratory staff for the continuous monitoring of operation and the results of measurements in order to decide whether results are reliable enough to be released
is apertional technique and activity within production site that are used to fulfill .
We need to do internal quality control to ensure that test result are reliable and reproducible and control quality of daily routine work.
The aim of IQC to monitor the analytical method an detection of any deviation during the analysis.
Use in IQC different control sera like:
Pooled , commerationally prepared control sera and duplicate test on patient specimen.
Conditions where independent test results are obtained with the same method on identical
test items in the same laboratory by the same operator using the same equipment within
short intervals of time.
Material used for the purposes of internal quality control and subjected to the same or part
of the same measurement procedure as that used for test materials. Reference materials can
be used as control material. Ideal control materials are the certified ones.
4- During the analytical:
Adequate volume from the sample and reagent and adequate mix is important to having correct result and in addition to inturtion time and temperature due to there are many examination effect by the temperature and duration.
Run (analytical run:
Set of measurements performed under repeatability conditions
Range of circumstances that contribute to the quality of analytical data, including equipment, reagents, procedures, test materials, personnel, environment and quality,,,,
Two main categories of analytical error are recognised, namely random errors and systematic errors, which give rise to imprecision and bias respectively The importance of categorizing error in this way lies in the fact that they have different sources, remedies and consequences for the interpretation of data.
Random errors determine the precision of measurement. They cause random positive and negative deviations of results about the underlying mean value.
Systematic errors comprise displacement of the mean of many determinations from the true value. For the purposes of IQC two levels of systematic error are worth consideration.
(1) Persistent bias affects the analytical system (for a given type of test material) over a long period and affects all data. Such bias, if small in relation to random error, may be identifiable only after the analytical system has been in operation for a long time. It might be regarded as tolerable, provided it is kept within prescribed
(2) (2) The run effect is exemplified by a deviation of the analytical system during a particular run. This effect, where it is sufficiently large, will be identified by IQC at the time of occurrence as an out-of-control condition.
5- Reading the result:
Report results accuracy, clearly unambig usually objectively it include information necessary for it interpretation . Must be avoided in any deviation addition or exclusion from the result in the recording the result. And the result must be compliance with equipment .