• Reduced length of stay

• Reduced cost of stay

• Reduced turnaround time for diagnosis of infection

• Change to appropriate antimicrobial therapy

• Customer (physician or patient) satisfaction

Quality Program

Each laboratory must establish and maintain written policies and procedures that implement and monitor quality systems for all phases of the total testing process (preanalytic, analytic, and postanalytic) as well as general laboratory systems. The laboratory director is primarily responsible for the QC and QA programs. However, all laboratory personnel must actively participate in both programs. Federal guidelines (CLIA, 1988) are considered minimum standards and are superseded by higher standards imposed by states or private certifying agencies such as the College of American Pathologists (CAP) or The Joint Commission (TJC).

The basic elements of a QC program are described in the following sections.

Specimen Collection and Transport

The laboratory is responsible for providing written policies and procedures that ensure positive identification and optimum integrity of a patient’s specimen from the time of collection or receipt of the specimen through completion of testing and reporting of results.

These guidelines and instructions should be available to health care providers for use when specimens are collected. The written collection instructions should be in detail and include the following:

The collection instructions should include information on how a requisition should be filled out electronically or by hand, and the laboratory must include a statement indicating that the requisition must be filled out entirely. In addition to standard information, such as patient name, hospital or laboratory number, and ordering physician, other critical information includes (1) whether the patient is receiving antimicrobial therapy, (2) the suspect agent or syndrome, (3) immunization history (if applicable), and (4) travel history when certain microorganisms or parasites are suspected. The laboratory should also establish criteria for unacceptable specimens. Examples of unacceptable specimens include the following:

Sometimes, even though the specimen is not acceptable, the physician may ask that it be processed anyway. If this happens, a disclaimer should be put on the final report, indicating that the specimen was not collected properly and the results should be interpreted with caution.

Standard Operating Procedure Manual

The requirement for a Standard Operating Procedure Manual (SOPM) is considered part of the QC program. The SOPM should define test performance, tolerance limits, reagent preparation, required quality control, result reporting, and references. The SOPM should be written in the format of Clinical and Laboratory Standards Institute (CLSI), and must be reviewed and signed annually or bi-annually by the laboratory director who appears on the CLIA certificate; in addition, all changes must be approved and dated by the laboratory director. The SOPM should be available in the work areas. It is the definitive laboratory reference and is used often for questions relating to individual tests. Any obsolete procedure should be dated when removed from the SOPM and retained for at least 2 years.

Personnel

It is the laboratory director’s responsibility to employ sufficient qualified personnel for the volume and complexity of the work performed. For example, published studies regarding staffing of virology laboratories suggest one technologist per 500 to 1000 specimens per year. Technical on-the-job training must be documented, and the employee’s competency must be assessed twice in the first year and annually thereafter. Continuing education programs should be provided, and verification of attendance should be maintained in the employee’s personnel file. CLIA has improved the regulations associated with personnel competency (CLIA subpart K:493.1235). Laboratory employee competency assessment must include the following: (1) Direct observation of test performance, to include patient preparation (if applicable), specimen handling, processing, and testing; (2) monitoring the recording and reporting of test results; (3) review of intermediate test results or work sheets, QC results, patient results, and preventative maintenance records; (4) direct observation of performance or instrument maintenance and function checks; (5) assessment of test performance through testing previously analyzed specimens, internal blind testing of samples or external patients samples, and; (6) assessment of problem-solving skills. These competency assessments must be documented and completed by qualified personnel.

Reference Laboratories

Not all testing can be completed in one facility. A laboratory test that cannot be performed in-house and needs to be sent somewhere else is considered a reference laboratory test. The reference laboratory is a separate entity from the facility that collects and sends the specimen. It must be accredited or licensed. The referral laboratory’s name, address, and licensure numbers should be included on the patient’s final report.

Patient Reports

There should be an established system for supervisory review of all laboratory reports. This review involves checking the specimen workup to verify that the correct conclusions were drawn and no clerical errors were made in reporting results. Reports should be released only to individuals authorized by law to receive them (physicians and various midlevel practitioners). Clinicians should be notified about “panic values” immediately. Panic values are potential life-threatening results, for example, positive Gram stain for cerebrospinal fluid (CSF) or a positive blood culture. Reference ranges must be included on the report where appropriate. All patient records should be maintained for at least 2 years. In reality, records should be maintained for at least 10 years because they may be needed to support medical necessity in the event of a postpayment billing audit by the Centers for Medicare and Medicaid Services.

Proficiency Testing (PT)

Proficiency testing (PT) is a quality assurance measure used to monitor the laboratory’s analytic performance in comparison to its peers and reference standards. It provides an external validation tool and objective evidence of the laboratory competence for patients and accrediting and oversight agencies. Laboratories are required to participate in a PT program for each analyte (test) for which a program is available; the laboratory must maintain an average score of 80% to maintain licensure in any subspecialty area. The federal government no longer maintains a PT program, but some states, such as New York, as well as several private accrediting agencies, such as the College of American Pathologists (CAP), send out “blind unknowns.” These unknowns are to be treated exactly as patient specimens, from accessioning into the laboratory computer or manual logbook through workup and reporting of results. The testing personnel and laboratory director are required to sign a statement when the PT is completed attesting to the fact that the specimen was handled exactly like a patient specimen. In this way, PT specimens establish the accuracy and reproducibility of a laboratory’s day-to-day performance. The laboratory’s procedures, reagents, equipment, and personnel are all checked in the process. Furthermore, errors on PT help point out deficiencies, and the subsequent education of the staff can lead to overall improvements in laboratory quality. When grades (evaluations) come back, critiques (summaries) accompanying them should be discussed with the entire technical staff. Evidence of corrective action in the event of problems should be documented, including changes in procedures, retraining of personnel, or the purchase of alternative media and reagents.

Some laboratories have a system of internal PT in addition to those received from external agencies. When external audit is not available for a particular test method, laboratories are required by law to set up an internal program to revalidate the test at least semiannually. Internal PT samples can be set up by (1) seeding a simulated specimen and labeling it as an autopsy specimen so that no one panics if a pathogen is recovered, (2) splitting a routine specimen for workup by two different technologists, or (3) sending part of a specimen to a reference laboratory to compare and confirm the laboratory’s result.

Equipment logs should contain the following information:

Maintenance records should be retained in the laboratory for the life of the instrument. Specific guidelines regarding the periodicity of testing for autoclaves, biologic safety cabinets, centrifuges, incubators, microscopes, refrigerators, freezers, water baths, heat blocks, and other microbiology laboratory equipment can be found in a number of the references listed at the end of this chapter.

Antimicrobial Susceptibility Tests

The goal of quality control testing of antimicrobial susceptibility tests (ASTs) is to ensure the precision and accuracy of the supplies and microbiologists performing the test. The laboratory must check each lot number and shipment of antimicrobial agent(s) before, or concurrent with, initial use, using approved control organisms. Criteria regarding frequency of testing are the same regardless of the methodology, such as minimum inhibitory concentration (MIC) broth dilution or Kirby-Bauer (see Chapter 12). Each new shipment of microdilution trays or Mueller-Hinton plates should be tested with CLSI-approved American Type Culture Collection (ATCC [Rockville, Maryland]) reference strains.

Reference strains for MIC testing are selected for genetic stability and give MICs within the midrange of each antimicrobial agent tested. Reference strains for Kirby-Bauer testing have clearly defined mean diameters for the respective zone of inhibition for each antimicrobial tested. ATCC numbers of reference strains are different for various AST methods. Quality control MICs and zone diameters are annually updated and published by the CLSI Subcommittee on Antimicrobial Susceptibility Testing. New tables should be obtained from the CLSI regularly.

Each susceptibility test system must also be tested with use (usually daily) for 20 consecutive days. If three or fewer MICs or zone of inhibition diameters per drug-reference strain combination are outside the reference range during the 20-day testing period, laboratories may switch to weekly QC testing. Thereafter, aberrant results obtained during the weekly testing must be vigorously investigated. If a source of error, such as contamination, incorrect reference strain used, or incorrect atmosphere of incubation, is found, quality control testing may simply be repeated. However, if no source of error is uncovered, 5 consecutive days of retesting must be performed. If accuracy and precision are again acceptable, weekly QC testing may resume; if the problem drug/organism combinations are still outside the reference ranges, 20 days of consecutive testing must be reinitiated before weekly testing can be reinstated. Under no circumstances should any drug/organism combination be reported for a patient isolate if QC testing has failed.

Maintenance of QC Records

All QC results should be recorded and, when applicable, must include a review of the effectiveness of corrective actions taken to resolve problems, revision of policies and procedures necessary to prevent recurrence of problems, and discussion with appropriate staff. If temperature is adjusted or a biochemical test is repeated, the new readings within the tolerance limits should be listed. In many laboratories, the supervisor reviews and initials all forms weekly and the director then reviews each one monthly. QC records should be maintained for at least 2 years except those on equipment, which must be saved for the life of each instrument.

Maintenance of Reference QC Stocks

Stock organisms may be obtained from the ATCC, commercial vendors, or PT programs; well-defined clinical isolates may also be used. The laboratory should have enough organisms on hand to cover the full range of testing of all necessary materials such as media, kits, and reagents.

QA Program

Because QA is the method by which the overall process of infectious disease diagnosis is reviewed, any of the steps involved in the diagnosis of an infectious disease may be studied. These steps include the following:

Analytic testing (the work actually done in the microbiology laboratory) is now seen as only one part of a continuing spectrum of steps that begins when the physician orders the test and ends when he or she receives the results and treats the patient.

QA audits are planned and conducted by examining the three stages of testing. The goal is to look at the proficiency with which the patient is served by the whole facility, including the laboratory. The outcome is to look at the consequences to the patient of the work that has been performed. QA audits involve the analysis of how the system works and how it can be improved.

Q-Probes

One way to conduct a QA audit is to subscribe to the Q-Probes program, which is a national interlaboratory QA program developed and administered by CAP. CAP selects topics to be audited and provides instructions and worksheets for the collection of data as well as data entry forms. Data are collected for a specified period and then returned to CAP for analysis. CAP returns a summary of the institution’s performance as well as a comparison with other facilities of similar size and scope of service. That way, an individual facility can compare its results with those of its peers, a process called benchmarking. Q-Probes are designed for all areas of laboratory medicine. Since inception of the program, microbiology Q-Probe audits have included areas such as (1) blood culture utilization, (2) health care–associated (formerly nosocomial or hospital-acquired) infections, (3) cumulative susceptibility results, (4) antibiotic usage, (5) turnaround time of CSF Gram stains, (6) viral hepatitis test utilization, (7) laboratory diagnosis of tuberculosis, (8) blood culture contamination rates, (9) appropriateness of the ordering of stools for microbiology testing, and (10) sputum quality. Other laboratory-wide audits are also applicable to the microbiology laboratory, including error reporting, quality of reference laboratories, and effects of laboratory computer downtime.

In-House QA Audits

A facility that does not subscribe to the Q-Probe program may select topics for audits through suggestions from the medical, nursing, or pharmacy staff; complaints from the medical or nursing staff; or deficiency or observations noted in the laboratory.

Physicians may suggest an audit to measure the transcription accuracy of their orders by nursing unit clerical personnel. Nursing administrators may suggest an audit of contaminated urine cultures to access the compliance of the nursing staff in instructing patients about proper urine culture collection techniques. Pharmacists may notice improper antibiotic utilization by the clinical staff—for example, a patient was not placed on the appropriate therapy after the pathogen was reported or the patient remains on antibiotic therapy to which his or her organism is resistant after the susceptibility report has been charted. Complaints from the medical or nursing staff can involve failure of the laboratory to conduct all the tests requested on the requisition, performance of the wrong test, or an unexpected delay in turnaround time of test results. All complaints to the laboratory must be documented. Corrective action and follow-up with the laboratory, medical, and nursing staff must also be documented.

Deficiencies or problems in the laboratory performance should also be documented. If, for example, the laboratory notices a dramatic rise in the number of positive respiratory syncytial virus (RSV) direct antigen tests in the summer (not RSV season) and the problem is traced back to a quality control problem that a new employee did not recognize, a QA audit might be indicated to study the outcome of the patients, including inappropriate treatment for RSV and failure to institute treatment for the true causative agent. Alternatively, microbiologists may notice they are receiving many ova and parasite (O&P) examinations and stool cultures on patients hospitalized for more than 3 days. Because current cost containment guidelines suggest that this is inappropriate, the microbiology laboratory personnel could undertake a study to determine the percentage of positive results and the number of patients who tested positive for Clostridium difficile cytotoxin, which is the more likely cause of diarrhea in patients hospitalized for more than 3 days. If the audit showed that none of the stool cultures or O&P examinations tested positive and no stools were analyzed for C. difficile cytotoxin, then these findings would be presented to the medical staff. Some months following the medical staff in-service, the number of stool culture and O&P requests on patients hospitalized longer than 3 days would be reevaluated. It is hoped this would result in a dramatic decrease in numbers of inappropriate tests.

Conducting a QA Audit

Box 78-1 is an example of how an in-house QA audit may be conducted.

Continuous Daily Monitoring

Daily activities of microbiologists and supervisory personnel ensure that patients get the best quality care. These activities include (1) comparing results of morphotypes seen on direct examinations with what grows on the culture to ensure that all organisms have been recovered, (2) checking antimicrobial susceptibility reports to verify that profiles match those expected from a particular species, and (3) studying culture and susceptibility reports for clusters of patients with unusual infections or multiple-drug–resistant organisms. These and many other processes result in continual improvement to all test systems, ultimately resulting in quality patient care.