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Biomedical subjects

D J Boone

Publications and source records attributed to D J Boone.

16 recordsLinked to original sources

Toward optimal laboratory use. Problems in laboratory testing in primary care.

OBJECTIVE: To examine the frequency and characteristics of problems in laboratory testing in primary care physicians's offices and their impact on health care. DESIGN: Prospective descriptive study in which participating office-based primary care clinicians reported each occurrence of any laboratory incident during a 6-month study. Each identified problem was reported on a structured data collection instrument with an open-ended description of the problem. SETTING: Primary care physicians' offices in North America. PARTICIPANTS: One hundred twenty-four primary care clinicians in 49 practices of the Ambulatory Sentinel Practice Network (ASPN). MAIN RESULTS: A total of 180 problems were reported, yielding a crude rate of 1.1 problems per 1000 patient visits. Problems involving test ordering and specimen handling were the most common (56%), while those attributable to the test analysis itself accounted for 13% of the total. In the judgment of the practice staff, 27% of the reported problems had an impact on patient care. Of the 24 cases for which the specific impact was known and reported, half of the impacts were minor and about half were significant, as judged by whether or not the diagnosis and/or treatment of the patient was measurably affected. CONCLUSIONS: Clinically apparent problems with laboratory testing in primary care were found at a rate of 1.1 problems per 1000 patient visits. Of the laboratory problems that occurred in this study, 27% were judged by the physician to have an effect on patient care.

Clinical Laboratory Techniques↗

Indications and immediate patient outcomes of pathology intraoperative consultations. College of American Pathologists/Centers for Disease Control and Prevention Outcomes Working Group Study.

OBJECTIVE: To evaluate the reasons (indications) for and immediate intraoperative surgical results (outcomes) associated with pathology intraoperative consultation. DESIGN: In 1992 and 1993, surgeons collaborated with pathologists in 472 voluntarily participating institutions from the United States (462), Canada (7), Australia (2), and New Zealand (1) in a study jointly sponsored by the College of American Pathologists and the Centers for Disease Control and Prevention. Pathologists selected 20 consecutive intraoperative consultations and assembled a cover letter, a checklist questionnaire, and a copy of the corresponding surgical pathology report, all of which were sent to the surgeon(s) for retrospective evaluation. PARTICIPANTS: The study was distributed to participants in the College of American Pathologists voluntary Q-Probes quality improvement and Surgical Pathology Performance Improvement programs and to Canadian and Australian hospitals with more than 200 beds. RESULTS: Evaluation of 9164 cases established the five most common indications for intraoperative consultation: (1) establish or confirm diagnosis to determine type or extent of operation (51%), (2) confirm adequacy of margins (16%), (3) confirm nature of tissue to direct sampling for immediate culture or other laboratory study (10%), (4) expedite obtaining diagnosis to inform family or patient (8%), and (5) confirm sufficient tissue submitted to secure diagnosis in permanent section (8%). The information provided by the intraoperative consultation resulted in changed surgical procedures that were either modified, terminated, or newly initiated in 47%, 30%, 6%, 9%, and 28% of cases, corresponding respectively to each of the above five common indications. Rarely cited reasons for intraoperative consultation were to expedite obtaining diagnosis for surgeon's knowledge (3%), to facilitate patient management, other professional communication or discharge planning prior to permanent section availability (3%), academic protocol (< 1%), and consultation not needed or no reason for request (< 1%). CONCLUSIONS: This multi-institutional, interdisciplinary database confirms that pathology intraoperative consultations, regardless of the initial indications, influence immediate patient care decisions, resulting in changed surgical procedures in an average of 39% of all operative cases.

Australia↗

Transfusion medicine monitoring practices. A study of the College of American Pathologists/Centers for Disease Control and Prevention Outcomes Working Group.

OBJECTIVE: To survey transfusion medicine practices in 1990, to determine the distribution of defects in the transfusion process, to examine the relationship between defects and complications, and to recommend improvements in the transfusion process. DESIGN: A mail survey that divided the transfusion process into 24 risk-prone steps and gathered defect rates on each step, along with incidence data for eight known complications of transfusions and other demographic information. SETTINGS: Hospitals, independent laboratories, and blood centers that provide transfusion medicine services. OTHER PARTICIPANTS: Respondents were 1365 participants in the College of American Pathologists 1991 Blood Bank Quality Assurance Survey. RESULTS: While processing 6.2 million units of blood and blood products, respondents reported detecting over 88,000 defects: 41% in the preanalytic phase of testing, 55% in the postanalytic phase, and only 4% in the analytic phase, the phase to which most monitoring efforts were devoted. A median of eight steps were actively monitored by survey participants overall, whereas 96 facilities sought defects in all 24 steps. CONCLUSIONS: Analysis of the data showed several monitoring steps provide similar information. Although monitoring of the transfusion process could not be linked with prevention of the complications studied, active surveillance does focus attention on defect-prone steps and allows testing of strategies to improve the transfusion process. We describe how defect detection systems may be improved.

Blood Banks↗

Conducting outcomes research: past experience and future directions.

The Centers for Disease Control and Prevention (CDC) was delegated authority to conduct the studies mandated in the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Since that time, the CDC has been planning and implementing a research program, Evaluation of Quality of Laboratory Practices and Standards (EQLPS), aimed at demonstrating a clear linkage between patient outcome and laboratory practices and standards such as proficiency testing, quality assurance, and personnel standards. The goal of EQLPS is to improve the quality of laboratory medicine by providing a scientific and technical basis for laboratory practices and standards. In October 1995, the CDC will sponsor an Institute entitled "Frontiers in Laboratory Practice Research," during which strategies for conducting laboratory practice research will be discussed. The Institute should help identify research strategies that will eventually provide the information necessary to develop appropriate practice guidelines for laboratory medicine.

Centers for Disease Control and Prevention, U.S.↗

Governmental perspectives on evaluating laboratory performance.

The quality of laboratory analytical performance required to support medical decision-making has been defined in four major ways: (a) by the analytical variance of the state of the practice; (b) by the total variance, including analytical and biological variability; (c) by the loss of diagnostic efficiency attributable to analytical error; and (d) by medical-usefulness criteria. From the federal government's perspective, the answer to the question "How good must a laboratory test result be to be medically relevant?" must take into account the clinical context of the test, with accompanying concerns about access, timeliness, and cost, as well as limits for precision and accuracy in the analytical process and the frequency and potential patient-care impact of error in the pre- and postanalytical steps of the total testing process. Therefore, medically relevant goals should encompass not only analytical precision and accuracy but also goals to provide access to clinically effective tests and to reduce errors in the total testing process that can lead to medically misleading information. Development of more appropriate regulatory requirements for laboratories, as well as any needed improvements in instrumentation and methodology, should focus on ensuring that goals for medically relevant results are met by appropriate design and management of the entire process of laboratory testing.

Chemistry, Clinical↗

Literature review of research related to the Clinical Laboratory Improvement Amendments of 1988.

In conjunction with a 1990 Report to Congress on the studies required by the Clinical Laboratory Improvement Amendments of 1988 (CLIA '88), the Centers for Disease Control, Atlanta, Ga, prepared a summary of the existing scientific literature related to the five studies listed in Section 4 of the Act. Over 800 articles were identified that, by title, seemed to deal with subjects that have been assumed to be associated with the quality of clinical laboratory testing. Although our search was not exhaustive, we believe that the articles included in our search are representative of the scientific evidence that exists. Most of the articles collected in our initial search were later eliminated from additional review because they were determined to be evaluations of laboratory analytic methods, contained only anecdotal evidence, were primarily descriptions of methods or programs, or were opinion articles without specific scientific data to support the opinions. This review reports the conclusions drawn by the research investigators of the 90 referenced articles; it does not analyze each article to assess the scientific validity of the research nor does it critique each article that is included. The review points to the need for additional research to answer questions raised by CLIA '88.

Humans↗

Evaluating laboratory performance. Historical and governmental perspectives.

Historically, the quality of laboratory performance that must be provided to adequately support medical decision-making has been defined in three major ways: by the analytical variance of the state of the practice; by the total variance, including the expected analytical and biological variability; and by medical-usefulness criteria. Quality goals defined by these approaches have influenced instrument manufacturers, professional societies, governmental agencies, and even the precision and accuracy of medical practice. Despite past efforts, a consensus has not emerged on a scientifically and medically supportable set of laboratory performance requirements. Medically relevant goals for analytic performance would help avoid costly and unnecessary regulatory requirements and permit steady improvement in instrumentation and methods.

Government Agencies↗

Analytical variance and definition of a reference change as a function of calcium concentration.

Using data from the Centers for Disease Control (CDC) Proficiency Testing (PT) Surveys, we obtained estimates of repeatability (intralaboratory variability between results on the same material) and reproducibility (interlaboratory variability between results on the same material) for the Technicon SMA 6 (or 12/60) and SMAC 1 (or II) systems used with cresolphthalein complexone methodology to measure serum calcium. The two systems were comparable in terms of short-term (within-day) repeatability, long-term (three to six months) repeatability, short-term (one to two weeks) reproducibility, and long-term (three to six months) reproducibility. The long-term repeatability was essentially the same as the long-term reproducibility. Short-term repeatability, long-term repeatability, and long-term reproducibility increased linearly with increased calcium concentration over the range 1.75 to 2.95 mmol/L; short-term reproducibility showed no significant change over this range. The effect of analytical variance on the definition of a reference change in semiannual calcium measurements was demonstrated.

Analysis of Variance↗

Crisis in drug testing. Results of CDC blind study.

In response to questions about the reliability of the results of screening urine for drugs, we evaluated the performance of 13 laboratories, which serve a total of 262 methadone treatment facilities, by submitting prereferenced samples through the treatment facilities as patient samples (blind testing). Error rates for the 13 laboratories on samples containing barbiturates, amphetamines, methadone, cocaine, codeine, and morphine ranged from 11% to 94%, 19% to 100%, 0% to 33%, 0% to 100%, 0% to 100%, and 5% to 100%, respectively. Similarly, error rates on samples not containing these drugs (false-positives) ranged from 0% to 6%, 0% to 37%, 0% to 66%, 0% to 6%, 0% to 7%, and 0% to 10%, respectively. These blind tests indicate that greater care is taken with known evaluation samples than with routine samples, laboratories are often unable to detect drugs at concentrations called for by their contracts, and the observed underreporting of drugs may threaten the treatment process. Drug treatment facilities should monitor the performance of their contract laboratories with quality-control samples, preferably through blind testing.

Amphetamines↗

Results of a nationwide survey of analyses for creatine kinase and creatine kinase isoenzymes.

More than 300 laboratories participated in an interlaboratory survey of creatine kinase (CK, EC 2.7.3.2) determinations in which they analyzed seven lyophilized samples for total CK and CK isoenzymes and furnished information about their methodology. The samples were not necessarily intended to mimic typical patients' specimens but rather to determine the analytical ability of the laboratories to distinguish isoenzyme fraction CK-MB from CK-BB and to detect small but abnormal amounts of CK-BB. For total CK measurement, most laboratories used an NADP+ reduction method monitored at 340 nm (89%), and reported results in units per liter (U/L) (99%) at either 30 degrees C (34%) or 37 degrees C (60%). Despite the variety of analytical conditions, most laboratories (89%) correctly reported results within their normal range for all samples. The 287 laboratories that reported isoenzyme distributions in the samples used either cellulose acetate (37%) or agarose (44%) electrophoresis, ion-exchange chromatography (9%), or immunoinhibition (7%). Results from laboratories that used nonspecific CK-MB immunoinhibition techniques were biased when a significant amount of CK-BB isoenzyme was present.

Chemistry, Clinical↗

Laboratory evaluation and assistance efforts: mailed, on-site and blind proficiency testing surveys conducted by the Centers for Disease Control.

During the last three years, the Centers for Disease Control (CDC) has conducted: 1) on-site surveys in which trained personnel visited laboratories that had experienced performance problems in the quarterly mailed proficiency testing (PT) program, reviewing the laboratories' analytical procedures by using carefully referenced samples to determine sources of errors and providing assistance in correcting them; 2) special assistance surveys in which carefully referenced samples were mailed to laboratories that had performed unsatisfactorily in routine mailed PT surveys and then telephone consultations were conducted to correct the problems; and 3) blind surveys in which carefully referenced samples were sent through normal patient sample acquisition routes to assess the actual day-to-day performance capability of the laboratories. Results suggest that on-site surveys by trained laboratory surveyors and special mailed assistance surveys can be very effective in identifying the source of analytical errors in laboratories previously found, through mailed PT surveys, to have performance problems. Blind-survey results indicate that good performance in mailed PT does not necessarily imply good laboratory performance with routine patient specimens. Although difficult to conduct, blind surveys should be conducted whenever the logistics can be worked out by contractors for laboratory services, clinicians using laboratory services, and the laboratories themselves to assure the continuation of quality service.

Blood Chemical Analysis↗

Significance of gamma-glutamyl transferase (GGT) activity measurements in alcohol-induced hepatic injury.

Experimental evidence is presented that the determination of gamma-glutamyl transferase (GGT) activity in serum is useful in the assessment of alcohol-induced liver disease and for demonstrating to patients the toxic effects of their drinking habits on the liver. Serial measurements of GGT activity in serum have also proved valuable in monitoring the progress of therapy as well as alleged abstention from alcohol in the known alcoholic.

Adult↗