Biomedical subjects

G S Cembrowski

Publications and source records attributed to G S Cembrowski.

9 recordsLinked to original sources

PubMed1992

Evaluation of capillary collection system for HbA1c specimens.

OBJECTIVE: We evaluated the accuracy and stability of a capillary HbA1c collection system for use with a high-performance liquid chromatography analyzer. RESEARCH DESIGN AND METHODS: The collection system requires that 5 ul blood is drawn into a calibrated capillary tube, which is then placed into a vial of stabilizing solution and sent for analysis. The study was conducted on simultaneously drawn capillary and venous blood specimens from 47 pediatric diabetes patients. Accuracy was determined by comparing the capillary to the venous HbA1c values. Stability was measured by analyzing 17 capillary specimens over 3 wk. RESULTS: There was excellent agreement between the capillary and venous HbA1c values (capillary 0.959, venous +0.494, R2 = 98.7%). The capillary HbA1c values were 0.2% higher than the venous HbA1c values and decreased gradually over time (0.1% HbA1c/week) when stored at room temperature. CONCLUSIONS: The Bio-Rad (Richmond, CA) collection system is accurate, stable, and simple to use.

Blood Specimen Collection↗

PubMed1992

Achieving the Health Care Financing Administration limits by quality improvement and quality control. A real-world example.

With the enactment of the Clinical Laboratory Improvement Amendments of 1988 (CLIA 88), the federal government is now using proficiency testing as the primary indicator of laboratory quality. Laboratories with proficiency test failures are now at risk of a variety of harsh penalties including large monetary fines and suspension of operations. To minimize the risk of failed proficiency testing, we initiated a continuous quality improvement program in our general chemistry laboratory in conjunction with the use of a new survey-validated quality control product. This article describes the quality improvement program and our success in reducing the long-term random error in general chemistry. Despite our improvement program, significant analytical errors (greater than 30% of the CLIA limits) still exist in analytes measured by our chemistry analyzer. These errors are present in nearly the same analytes measured by other common chemistry analyzers indicating the need for improvement in their design and manufacture.

Blood Chemical Analysis↗

PubMed1992

Emergency department stat test turnaround times. A College of American Pathologists' Q-Probes study for potassium and hemoglobin.

We report aggregate turnaround times (TATs) from phlebotomy to result reporting of emergency department patients' hemoglobin and potassium results for 722 subscribers to the College of American Pathologists Q-Probes program. Approximately 40,000 specimens were obtained for each analyte. Median interinstitutional TAT time of 25 minutes for hemoglobin and 36 minutes for potassium varied little by shift, weekdays, or weekends. The type of personnel collecting the specimen and the method of specimen transport were the most important factors affecting TATs. Specimen transit times accounted for approximately one third of the total TATs, but when couriers transported hemoglobin specimens, the median transit time was equivalent to the median intralaboratory test TAT. The influence of various measures used to improve test transit and TATs is presented.

Bloodletting↗

PubMed1991

Laboratory phlebotomy. College of American Pathologists Q-Probe study of patient satisfaction and complications in 23,783 patients.

Outpatients from 630 institutions participated in a phlebotomy module of Q-Probes, a quality assurance program of the College of American Pathologists, Northfield, Ill. This module assessed patient outcome measurements of complications, discomfort, and satisfaction with the phlebotomy procedure. Of the 29,700 ostensibly healthy individuals registered, 80.1% returned postcards containing measurements and assessments they made about the procedure and information recorded by the phlebotomist. The median time required for phlebotomy was 6 minutes, with 25% of patients requiring less than 5 minutes and 10% more than 21 minutes for completion of the procedure. The average number of phlebotomy attempts per patient was 1.03, with 95 patients (0.4%) experiencing three to 11 attempts. Ecchymoses occurred in 4048 (16.6%) attempts, with the median size of ecchymosis being 15.1 mm. On the average, an outstanding employee was identified by patients 46.6% of the time. The discomfort caused by the needle puncture was more than expected by 35.3% of patients. Although 98.6% of the patients were satisfied, 336 patients were dissatisfied with the procedure. We conclude that the technical skills of phlebotomists and patient satisfaction with phlebotomy are outstanding, but that patient discomfort from the procedure needs to be minimized.

Bloodletting↗

PubMed1979

Statistical analysis of method comparison data. Testing normality.

A Lilliefors test of normality has been applied to data from precision and accuracy studies. Most data sets tested as non-normal. Simulation studies showed that the test is extremely sensitive to the rounded, narrowly distributed data that are typical of method performance studies in clinical chemistry. The Lilliefors test can be modified to be applicable to rounded data so that it gives fewer indications of non-normality. The authors conclude that the selection of a test of normality requires careful study of the properties of the test. Otherwise, the subsequent choice between parametric and nonparametric statistics may not be meaningful.

Chemistry, Clinical↗

PubMed1978

Computer-controlled instrument system for sequential chemical testing III. Application to liver assessment.

We used the previously described [Clin. Chem. 19, 1114 (1973)] and evaluated [Clin. Chem. 19, 1122 (1973)] computer-controlled instrument system for sequential chemical testing to select and perform tests of hepatic status, to aid the clinician in the diagnosis of liver disease. Results for total bilirubin, aspartate aminotransferase, and alkaline phosphatase obtained from the continuous-flow analysis (SMA 12/60) admission screen were used by the instrument system to determine selectively the values for gamma-glutamyltransferase, alanine aminotransferase, creatine kinase, and total and direct bilirubin. Kit methods for the latter four tests were evaluated on the system; results were similar to manual procedures. A software, enzymatic ratemeter was found to be better than the previously described hardware ratemeter. The follow-up tests of serum prescribed by the system are compared to clinician-prescribed follow-up tests and discharge diagnoses. In 10 of 19 cases, the system and clinician ordered similar follow-up tests; in three cases follow-up differed, and in six cases, the system ordered follow-up tests and the clinician ordered none.

Adult↗

PubMed1976

Computer-assisted differential diagnosis of laboratory abnormalities and follow-up testing. Evaluation of the accuracy of a computer program.

An evaluation is made of a computer program which generates a differential diagnostic list given a set of input data obtained from an admission chemistry screening profile. The program is tested by supplying input data on patients for whom diseases are known. The laboratory data from 367 patients are examined. Accurate computer diagnosis is obtained in many disease categories. The original computer program is modified to suggest the follow-up tests indicated based on the diagnoses it makes. By using this program and some additional clinical input from the physician, the clinical pathologist can select the most appropriate computer diagnosis and begin the follow-up testing. Accelerated diagnosis and patient care should result.

Aged↗

PubMed1975

A versatile temperature-controlled reaction cuvet.

A thermostatted reaction cuvet, operating under computerized or manual temperature control in the ultraviolet or visible region, is described and evaluated. The cell was designed for use with the automated chemistry system described earlier [Clin. Chem. 19, 1114 (1973)], but can readily be adapted for other applications. The entire 3-ml cuvet assembly warms from ambient temperature to 37 degrees C in less than 10 min, with plus or minus 0.15 degrees C stability; the long-term stability is plus or minus 0.05 degrees C; temperature recovery time after washing or reagent addition is less than 3 min. The optical pathlength is 10.00 mm and the carryover volume is 18 mu-l.

Alanine Transaminase↗

PubMed1975

Trend detection in control data: optimization and interpretation of Trigg's technique for trend analysis.

A method for trend detection, Trigg's technique [Oper. Res. Q. 15, 271 (1964)], has been investigated for use in monitoring trends in control data produced by multitest continuous-flow analyzers. Simulated trend data were used to optimize the method. Actual control data were analyzed retrospectively to determine the frequency of trends and the accuracy of several parameters obtained from Trigg's method. The prospective use of the technique has successfully uncovered important trends. Criteria for the interpretation of the Trigg's trend data are suggested and an algorithm for the computer implementation of Trigg's calculations is included.

Autoanalysis↗