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Quality assurance and sourcesof error in district laboratory

practiceDr. Hafez Alsumairy

Diagnostic & Molecular Microbiology2014-2015

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Quality assurance and sources of error in district laboratorypractice

• The purpose QA in laboratorypractice is to provide test resultsare:– relevant– reliable and reproducible– timely– interpreted correctly

• QA includes all those activitiesboth in and outside thelaboratory

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Quality assurance and sources of error in district laboratorypractice

• Implementing QA requires1. Preparation and use of SOPs

with details of QC2. System for monitoring

whether test results arereaching early

3. Policies of work

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Standard operating procedures (SOPs)

• Local laboratory bench manual1. To improve and maintain the quality of laboratory service to patients and

identify problems associated with poor work performance2. To provide laboratory staff with written instructions3. To prevent changes in the performance of tests4. To make clinical and epidemiological interpretations of test results easier5. To provide written standardized techniques for use in the training6. To facilitate the preparation of a list and inventory7. To promote safe laboratory practice

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Important features of SOPS

SOPs must be:1. Applicable and achievable in the laboratory in which they will be

used.2. Clearly written and easy to understand and follow.3. Kept up to date using appropriate valid technologies

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Important features ofSOPSPreparing SOPsA suggested layout for districtlaboratory SOPs and appendices

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Sources of errors in district laboratorypractice• Most errors are associated with:

1. – Misidentifying a patient2. – Collecting or storing a specimen incorrectly.3. – Technical imprecision and inaccuracy.4. – Reader variability.5. – Adverse laboratory working conditions.6. – Misinterpreting test reports.

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Sources of errors in district laboratorypractice1. Patient misidentification

a. Clerical errors or incomplete identification datab. Language difficultiesc. Specimen containers that are incorrectly labelled or when a specimen is

misidentified on a wardd. No reliable check-in system

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Sources of errors in district laboratorypractice2. Faulty specimens

i. A specimen is not correct, is inadequate, or collected at an incorrect timeii. The collection technique is not correctiii. A container has not been cleaned properlyiv. The container cap is loosev. A specimen is unsuitable for testingvi. Specimens, particularly blood films are not protectedvii. A specimen contains drugsviii. There is no inspection of specimens

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Sources of errors in district laboratorypractice3. Imprecision and inaccuracy

The Commonest causes of inconsistent random errorsi. Incorrect and variable pipetting and dispensingii. Inadequate mixing of sample with reagents.iii. Samples are not incubated consistently where incubation of tests is

required.iv. Glassware or plastic ware is not clean or dried completely before reuse.v. Equipment malfunctionvi. Incomplete removal of interfering substancesvii. Laboratory staff prepare a smear that is too thickviii. Incorrect reporting of microscopical preparations and lack of

standardization in reporting

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Sources of errors in district laboratorypractice3. Imprecision and inaccuracy

The commonest causes of consistent systematic errorsi. Incorrect or infrequent calibration of a test methodii. Using an automatic pipettor set at an incorrect volumeiii. Use of control sera that has been wrongly prepared, incorrectly storediv. Consistent calculation errorv. Incubating samples at an incorrect temperaturevi. Use of unsatisfactory reagentsvii. Staff reporting microscopical preparations incorrectly

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Mistakes made by laboratory staff due toadverse working conditions• The workload is too high or too low• The laboratory size and structure• Laboratory staff become professionally isolated• There are too many interruptions• When there are too many urgent test requests• District hospital laboratory staff become fatigued or sick

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EXTERNAL QUALITY ASSESSMENT (EQA)

• EQA for the district hospital laboratory• Not yet operating in most tropical and developing countries due to

1. Lack of commitment,2. Inadequate resourcing,3. Too few laboratory personnel trained in QA, and4. Difficulties in transporting and mailing pathological specimens.

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Communicating effectively

• Communication is the accurate passing on or sharing of information• – by writing

• – presented legibly and neatly,• – expressed clearly and simply.

• – by speaking• – clarity of speech and language used.• – tone of voice.• – ability to speak informatively.

• – by actions

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Thank youAny questions

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