Quality in Haematology Flashcards
Define accreditation
It is the formal third party recognition of the competence of an organisation to
carry out specific tasks
It is a recognised mechanism for assuring the quality & competence of the
services & products provided by an organisation worldwide
Write about medical laboratory inspection
Most inspected healthcare professionals within the healthcare system
Irish national accreditation body (INAB) inspect annually
Certificate is valid for 5 year cycles
Write about ISO15189
The overall Goal of ISO 15189: Medical laboratories—particular requirements for quality and competence, is patient safety
The standard requires medical labs to implement a quality management system (QMS)
And to create standardised processes that ensure staff understand and
always follow correct procedures to produce consistent results each time a process is undertaken
QMS is a collection of business processes focused on achieving your quality policy and quality objectives — i.e. what your customer wants and needs
What is quality assurance
An overall management plan to guarantee the integrity of data
What is quality control
A series of analytical measurement used to assess the quality of the analytical data
What are some pre analytical variable
- Collected from right patient and labelled appropriately, mixed
appropriately - Not from a drip site, delivered to lab promptly
- No contamination from incorrect anticoagulant
- Storage above room temperature causes fragmentation of red cells –
false high platelet count - Coagulation factors V and VIII are labile (4hr max)
- Haemolysed samples (Incorrect Hb, Will activate coagulation factors)
- Clotted sample/Partially Clotted/Activated sample
Write about validation of methods
- Method must correlate to reference method
- The method must be suitable for the intended
use - Measure its performance characteristics
– Accuracy
– Precision
– Linearity
– Limit of detection
– Interfering substances
– Reference range
– Uncertainty of measurement
Define precision
How well a series of measurements
agree with each other: It is the
closeness of agreement between
independent test results obtained
under stipulated conditions
Define accuracy
How well a measurement agrees with
an accepted value: it is the closeness
of the agreement between the result
of a measurement and a true value
of the measurement
Write about haematology controls
Haematology controls tend to be fixed cells with 3 month storage at 4°C
Stable for a few hours at room temp.
Mix correctly before use
May need to be analysed through a special QC channel on instrument
Fixed cells may not perform the same as fresh cells in the automated cell analyser – beware using for calibration
Some labs also use a ‘Drift Control’ which is made locally or bought commercially without pre-assigned values
Lab assigns values by analysing the QC material 10 times and calculating
mean and SD
What are some FBC abnormalities
Cold agglutinins -> red cells clump at RT, high MCH
Lipaemia/Icteric sample -> falsely high Hb measured
Falsely low platelet count -> platelet agglutination, giant platelets
What are some FBC confirmatory test
Delta Checking: previous results
Manual white cell count using Haemocytometer
Spectrophotometric measurement of Hb using reference standard
Platelet count on flow cytometer using CD61/CD59
Blood film examination
Write about coagulation confirmatory tests
- Check pre-analytical variables NB clots
- Always repeat
- Sampling problems
- Bubbles in sample cup
- Clot in sample probe
- Sampling too close to interface
- Repeat with extended clot observation time
- Check clinical details eg. OAT / Heparin
Write about External Quality Assessment
- All reportable tests on the scope must be attached to an EQA Scheme/Inter-
Laboratory Comparison Programme - Specimens must be treated in the same way as patient samples
- Must have a documented procedure in place in the event of an EQA failure to
implement Corrective Action (CA) - Provides a comparison of results obtained on the same sample among different
Laboratories (peer group) - EQA Schemes: NEQAS (UK), IEQAS (Labquality- Finland), Qualiris (Stago-
Coagulation), ECAT (External quality Control of diagnostic Assays & Tests) with a
focus on Thrombosis & Haemostasis, Netherlands - Distributions/Surveys per year e.g. FBC: 12 per annum
Write about EQA report and evaluation of laboratory performance
The methods by which each scheme evaluates performance is variable
Individual results are assessed against a target value
Mean, SD & CV are calculated
Gaussian Distribution plot
Deviation Index/z-score is also calculated
Grading systems A-E in Coagulation
