Denielle  Genesis  B.  Camato  

   III.  QUALITY  ASSESSMENT  &  MANAGEMENT  IN  THE  URINALYSIS  LABORATORY  ANALYSIS  OF  URINALYSIS  AND  BODY  FLUIDS  |  REVIEWER  

 

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QUALITY ASSESSMENT (QA) r refers to the overall process of guaranteeing quality patient

care and is regulated throughout the total testing system. r program includes:

ê testing controls also called Quality Control ê continual monitoring of the entire test ordering ê specimen collection through reporting ê interpreting results ê Essential to this program is having written

remedial actions mandating the steps to take when any part of the system fails.

QA

r PRE ANALYTICAL FACTORS r ANALYTICAL FACTORS r POST ANALYTICAL FACTORS

INCLUDED IN QA PROGRAME ARE:

ê procedure manuals ê internal quality control ê external quality control ê standardization ê proficiency testing (PT) ê record keeping ê Equipment maintenance ê Safety programs ê Training ê Education ê Competency assessment of personnel ê Documented and review process

URINALYSIS PROCEDURE MANUAL

ê A procedure manual containing all the procedures performed in the urinalysis section

ê must be available for reference in the working area ê must comply with the CLSI guidelines ê Whenever changes are made, the procedure should be

reviewed and signed by a person with designated authority LABORATORY PROCEDURE MANUAL

ê Title of the assay ê Principle of the procedure and statement of clinical

applications ê Protocol of specimen collection and storage ê QC information ê Reagents, supplies and equipment ê Procedural protocol ê “Normal” reference ranges ê Technical sources of error ê Limitations of the procedure ê Proper procedures for specimen collection and storage

PRE-ANALYTICAL FACTORS

ê test requests ê patient preparation ê specimen collection ê handling ê storage

r Good communication of departments and correct procedures,

r improves the Turn Around Time (TAT) of results , r avoids duplication of tests and ensures high

quality specimen.

SPECIMEN COLLECTION AND HANDLING ê The actual date and time of specimen collection ê Whether the specimen was refrigerated before transporting ê The time the specimen was received in laboratory and the

time it was performed ê Test requested ê An area of specific instructions that might affect the

results of the analysis ê Patient identification information

r Patient’s sex r Age r Date of birth r The source of specimen r Time must be documented.

PATIENT PREPARATION

ê Fasting or elimination of interfering medications ê Type of volume of specimen required ê Sterile or opaque container must be included in the specific

procedure ê urine specimens should be examined within 2 hours ê If this is not possible:

r written instructions for the preservation of the specimen

EXAMPLES OF PRE-ANALYTICAL ERRORS

ê Specimen obtained from wrong patient ê Specimen procured at the wrong time ê Specimen collected in the wrong tube or container ê Incorrect labeling of specimen ê Improper processing of specimen

POLICY FOR HANDLING OF MISLABELED SPECIMEN

ê Do NOT assume any information about the specimen or patient.

ê Do NOT relabel an incorrectly labeled specimen. ê Do NOT discard the specimen until investigation is complete. ê Leave specimen EXACTLY as you receive it; put in the

refrigerator for preservation until errors can be resolved. ê Notify floor, nursing station, doctor’s office, etc. of problem

and why it must be corrected for analysis to continue. ê Identify problem on specimen requisition with date, time, and

your initials. ê Make person responsible for specimen collection participate

in solution of problem(s). Any action taken should be documented on the requisition slip.

ê Report all mislabeled specimens to the quality assurance board.

ANALYTICAL ERRORS

ê Are the processes that directly affect the testing of specimens.

r Reagent and test performance r instrument calibration and maintenance r QC r personnel requirements r technical competence

Denielle  Genesis  B.  Camato  

   III.  QUALITY  ASSESSMENT  &  MANAGEMENT  IN  THE  URINALYSIS  LABORATORY  ANALYSIS  OF  URINALYSIS  AND  BODY  FLUIDS  |  REVIEWER  

 

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REAGENTS ê Manual should state the name and chemical formula of each

reagent used, instructions for preparation, company source of prepared materials storage requirements and procedures for reagent QC.

ê A bold type statement of any safety or health precautions associated with reagents should be present. E.g. the heat produced in Clinitest reaction

ê All reagent and reagent strips must be properly labeled with the date preparation or opening, purchase and received date, expiration date, and appropriate safety information.

ê Reagent strips should be checked against known negative and positive control solutions on each shift or at a minimum once a day, and whenever a new bottle is opened.

ê Reagents are checked daily or when tests requiring their use are requested.

ê Results of all reagent checks are properly recorded. INSTRUMENTATION AND EQUIPMENT

ê Most frequently encountered instruments in urinalysis laboratory:

ê Refractometers ê Osmometers ê Automated reagent strip readers ê Automated microscopy instruments

CALIBRATION OF INSTRUMENT

ê REFRACTOMETERS are calibrated on each shifts against distilled water (1.000)

ê Known control } 5% saline (1.022 ±0.001) 9% sucrose (1.034 ±0.001)

ê Commercial control r Osmometer r Urine reagent strip test r hCG kit tests

CALIBRATION OF INSTRUMENT

ê Automated urinalysis systems and reagent strip readers are calibrated using manufacturer-supplied calibration materials following the protocol specified by he manufacturer.

ê Both positive and negative control values must be run and recorded

[ Failed QC test must be documented--- no patient’s testing may be performed until QC is acceptable.

TEST PROCEDURE

ê Detailed and concise testing instructions are written in a step-by-step manner.

ê It should begin with: þ specimen preparation þ the time and speed of centrifugation þ materials and types of glassware needed þ time limitations þ the stability of specimens and reagents þ calculation formula þ a sample calculation, health and safety precautions.

QUALITY CONTROL ê Quality control refers to the materials, procedures, and

techniques that monitor the accuracy, precision, and reliability of a laboratory test.

ê QC are performed to ensure that acceptable standards are met during the process of patient testing.

ê Must be done at the beginning of each shift

ê Is a process that monitors the accuracy and reproducibility of results through the use of control specimens.

ACCURACY ê Refers to how closely the measurement approaches the

true value of the substance being analyzed. ê Synonymous with CORRECTNESS

CALIBRATION

ê Is the comparison of an instrument measure or reading to a known physical constant.

CONTROL ê Represents a specimen with a known value that is similar in

composition. PRECISION

ê Synonymous with REPRODUCIBILITY and measures the inherent variability of the test.

STANDARDS

ê Are highly purified substance of a known composition. SPECIFICITY VS SENSITIVITY SPECIFICITY SENSITITIVITY * Test is defined as the proportion * Defines as the proportion of of cases with absence of specific cases with specific disease or disease or condition that gives condition that gives positive negative result. result. * represents what is being measured * increase sensitivity – amount * it don’t measure interfering or similar of assayed substance is substances. Measured. 6 WESTGARD RULES FOR ANALYSIS OF QUALITY CONTROL CHARTS

ê 1 point is outside 2 SD ê If 1 point is outside 2 SD, then reject when:

þ 1 point is outside 3 SD (13s) þ 2 consecutive points are outside 2 SD on the

same side of the center line (22s) þ Range of 2 points greater than 4 SD ( R4s) þ 4 consecutive points exceed 1 SD on the same

side of the center lin (41s) þ 10 consecutive points are above or below the

mean (10x)

Denielle  Genesis  B.  Camato  

   III.  QUALITY  ASSESSMENT  &  MANAGEMENT  IN  THE  URINALYSIS  LABORATORY  ANALYSIS  OF  URINALYSIS  AND  BODY  FLUIDS  |  REVIEWER  

 

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EXTERNAL QUALITY CONTROL MONITORING ê External quality controls are used to verify the accuracy

and precision of a test and are exposed to the same conditions as the patient samples.

ê Rel iabi l ity is the ability to maintain both precision and accuracy.

ê Control mean is the average of all data points ê Standard deviation (SD) is a measurement statistic that

describes the average distance each data point in a normal distribution is from the mean.

ê Coefficient of variation (CV) is the SD expressed as a percentage of the mean. CV indicates whether the distribution of values about the mean is in a narrow versus broad range and should be less than 5%. Confidence intervals are the limits between which the specified proportion or percentage of results will lie.

TREND

ê Changes in accuracy of results are indicated. Shift

ê That is an abrupt change in the mean ê Changes in precision are shown by a large amount of scatter

about the mean and an uneven distribution above and below the mean that are most often caused by errors in technique.

INTERNAL CONTROL MONITORING

ê Consist of internal monitoring system built in to the test system and may be called electronic, internal, or procedural controls.

ê Internal or procedural controls monitor the correct addition of a patient specimen or reagent, the instruments/reagents interaction, and test completion.

PROFIECIENCY TESTING

ê It is the testing if unknown samples received from an outside agency.

ê It provides unbiased validation of the quality of patient test results.

SUMMARY OF QUALITY ASSURANCE ERRORS PREANALYTICAL

Patient misidentification Wrong test ordered Incorrect urine specimen Type collected Insufficient urine volume Delayed transport of urine to the laboratory Incorrect storage or preservation of urine

ANALYTICAL

Sample misidentification Erroneous instrument calibration Reagent deterioration Poor testing technique Instrument malfunction Interfering substances present Misinterpretation of quality

POSTANALYTICAL

Patient misidentification Poor handwriting Transcription error Poor quality of instrument printer Failure to send report Failure to call critical values Inability to identify interfering substances