Peter J. Howanitz

Errors in Laboratory Medicine Practical Lessons to Improve Patient Safety

CONTEXT Patient safety is influenced by the frequency and seriousness of errors that occur in the health care system. Error rates in laboratory practices are collected routinely for a variety of performance measures in all clinical pathology laboratories in the United States, but a list of critical performance measures has not yet been recommended. The most extensive databases describing error rates in pathology were developed and are maintained by the College of American Pathologists (CAP). These databases include the CAPs Q-Probes and Q-Tracks programs, which provide information on error rates from more than 130 interlaboratory studies. OBJECTIVES To define critical performance measures in laboratory medicine, describe error rates of these measures, and provide suggestions to decrease these errors, thereby ultimately improving patient safety. SETTING A review of experiences from Q-Probes and Q-Tracks studies supplemented with other studies cited in the literature. DESIGN Q-Probes studies are carried out as time-limited studies lasting 1 to 4 months and have been conducted since 1989. In contrast, Q-Tracks investigations are ongoing studies performed on a yearly basis and have been conducted only since 1998. Participants from institutions throughout the world simultaneously conducted these studies according to specified scientific designs. The CAP has collected and summarized data for participants about these performance measures, including the significance of errors, the magnitude of error rates, tactics for error reduction, and willingness to implement each of these performance measures. MAIN OUTCOME MEASURES A list of recommended performance measures, the frequency of errors when these performance measures were studied, and suggestions to improve patient safety by reducing these errors. RESULTS Error rates for preanalytic and postanalytic performance measures were higher than for analytic measures. Eight performance measures were identified, including customer satisfaction, test turnaround times, patient identification, specimen acceptability, proficiency testing, critical value reporting, blood product wastage, and blood culture contamination. Error rate benchmarks for these performance measures were cited and recommendations for improving patient safety presented. CONCLUSIONS Not only has each of the 8 performance measures proven practical, useful, and important for patient care, taken together, they also fulfill regulatory requirements. All laboratories should consider implementing these performance measures and standardizing their own scientific designs, data analysis, and error reduction strategies according to findings from these published studies.

Physician Satisfaction and Emergency Department Laboratory Test Turnaround Time

OBJECTIVES To determine the length of time for the components of the emergency department (ED) turnaround time (TAT) study in 1998 and to ascertain physician satisfaction concerning laboratory services to the ED. METHODS Using forms supplied by the College of American Pathologists Q-Probes program, participants conducted a self-directed study of ED TAT over a 4-week period. Data requested included various times of day associated with the ordering, specimen collection, laboratory receipt, and result-reporting stages of stat ED TATs for potassium and hemoglobin. Additionally, practice-related questions associated with the laboratory were asked. Participating laboratories also provided a physician satisfaction survey for up to 4 physicians who were users of ED services. Results of both the TAT study and the physician satisfaction survey were returned by mail. Participants were drawn from the 952 hospital laboratories enrolled in the 1998 College of American Pathologists Q-Probes study on ED TAT. The main outcome measures included the components of the ED TAT process, factors associated with decreases in ED TAT, and the results of the physician satisfaction survey. RESULTS Six hundred ninety hospital laboratories (72.4% response rate) returned data on up to 18 230 hemoglobin and 18 259 potassium specimens. Half of these laboratories responded that 90% of potassium tests were ordered and reported in 69 minutes or less, whereas the TAT for 90% of hemoglobin results was 55 minutes or less. Comparison of the components of TAT for both potassium and hemoglobin with similar studies done in 1990 and 1993 showed no change. Factors found to statistically contribute to faster TATs for both tests were laboratory control of specimen handling and rapid transport time. When whole blood specimens were used for potassium determination, TAT improved. Emergency department physicians chose the study-defined lower satisfaction categories of Often, Sometimes, Rarely, and Never for the questions concerning the laboratory being sensitive to stat testing needs (39.1%) and meeting physician needs (47.6%). Many of the physicians surveyed believed that laboratory TAT caused delayed ED treatment more than 50% of the time (42.9%) and increased ED length of stay more than 50% of the time (61.4%) when compared with other specialty users of the ED. CONCLUSIONS Laboratory ED TATs have remained unchanged for almost a decade. Emergency department physicians are not satisfied with laboratory services. Although it appears that one issue may relate to the other, the interaction between the laboratory and the ED is quite complex and has been evolving for at least 30 years. Improvement in interoperability between the departments is essential for operational efficiency and patient care. Effective communication channels need to be established to achieve these goals.

Q-tracks: A College of American Pathologists program of continuous laboratory monitoring and longitudinal performance tracking

CONTEXT Continuous monitoring of key laboratory indicators of quality by hundreds of laboratories in a standardized measurement program affords an opportunity to document the influence of longitudinal tracking on performance improvement by participants focused on that outcome. OBJECTIVE To describe the results of the first 2 years of participation in a unique continuous performance assessment program for pathology and laboratory medicine. DESIGN Participants in any of 6 modules in the 1999 and 2000 College of American Pathologists (CAP) Q-Tracks program collected data according to defined methods and sampling intervals on standardized input forms. Data were submitted quarterly to CAP for statistical analysis. Interinstitutional comparison reports returned in 6 weeks provided each laboratory with its performance profile of key indicators and its percentile ranking compared with all participants in that quarter. This also included longitudinal comparisons of performance during previous cumulative quarters. Control charts graphically displayed data with flags identifying performance points that were out of statistical control. SETTING Hospital-based laboratories in the United States (98%), Canada, and Australia. PARTICIPANTS Voluntary subscriber laboratories in the CAP Q-Tracks performance measurement program: roughly 70% from hospitals of 300 occupied beds or fewer, 65% from private, nonprofit institutions, slightly more than half located in cities, one third from teaching hospitals, and 20% with pathology residency training programs. MAIN OUTCOME MEASURES Each module measured several major and additional minor quality indicators and unbenchmarked individualized data for internal use. RESULTS Participants in 4 of 6 Q-Tracks continuous monitors demonstrated statistically significant performance improvement trends in 1999 and 2000, which were most marked for laboratories that continued participation throughout both years. These monitors were wristband patient identification, laboratory specimen acceptability, blood product wastage, and intraoperative frozen section consultation. CONCLUSIONS Key continuous indicators chosen on the basis of a decades experience in the CAP Q-Probes quality improvement program are useful measurement and benchmarking tools for laboratories to improve performance. In general, measures in which there is a broad range of demonstrable performance initially are most optimal for subsequent improvement using continuous monitoring. These studies have shown that quality is not static, but rather is a moving benchmark of performance as seen in the redefinition of benchmarks over time by participants in the first 2 years of the CAP Q-Tracks program.

Laboratory Results Timeliness as a Quality Attribute and Strategy

Although timeliness of results reporting has not been a major focus in clinical laboratories, there is increasing pressure from clinicians to report results rapidly. Even though there are only sparse data, timeliness in reporting of laboratory results undoubtedly affects clinician and patient satisfaction as well as length of hospital stay. Improving turnaround time (TAT) is a complex task involving education, equipment acquisition, and planning. All the steps from test ordering to results reporting should be monitored and steps taken to improve the processes. Various strategies to improve TAT at each step in the testing process are discussed.

Intraoperative Testing for Parathyroid Hormone: A Comprehensive Review of the Use of the Assay and the Relevant Literature

OBJECTIVE The rapid intraoperative parathyroid hormone assay is transforming the parathyroidectomy procedure. We present a review of the literature on the use of the assay as an adjunct to surgery. To our knowledge, this is the first review of the literature to encompass and compare all known primary studies of this assay in parathyroidectomy patients. DATA SOURCES Articles were collected by searching MEDLINE databases using relevant terminology. The references of these articles were reviewed for additional studies. Supplementary articles pertinent to the parathyroidectomy procedure, preoperative parathyroid localization studies, and intraoperative parathyroid hormone assay development also were examined. STUDY SELECTION AND DATA EXTRACTION One hundred sixty-five references were analyzed and categorized separately into groups. DATA SYNTHESIS The primary studies of intraoperative data on patients undergoing parathyroidectomy were compared when possible. Studies were analyzed by type of assay used, where performed, turnaround time, and efficiency of use. Reviews of the types of parathyroid surgery and preoperative localization were included for educational purposes.Conclusions.-The intraoperative parathyroid hormone assay is a useful adjunct to preoperative imaging and parathyroid surgery because of its unique ability to detect an occult residuum of hyperfunctioning parathyroid tissue. Use of this assay will obviate the need for frozen section in most routine cases. The test facilitates minimally invasive parathyroidectomy for single parathyroid adenomas, which, in turn, improves cost-effectiveness and cosmetic outcome. Its use in patients with known preoperative multiglandular disease is promising but requires further study.

The autopsy as a performance measurement tool--diagnostic discrepancies and unresolved clinical questions: a College of American Pathologists Q-Probes study of 2479 autopsies from 248 institutions.

OBJECTIVE To develop a multi-institutional reference database for quality improvement purposes using the autopsy to define clinical diagnostic discrepancies and resolve clinical questions. DESIGN Using the College of American Pathologists Q-Probes format, institutions prospectively assessed a maximum of 15 consecutive autopsies each, excluding forensic cases and stillborn infants, conducted over a 6-month period. They documented answers to clinical questions provided at autopsy and classified unexpected disease diagnoses according to a standardized system. SETTING AND PARTICIPANTS Hospital-based autopsies performed at 248 institutions participating in the 1993 College of American Pathologists Q-Probes Quality Improvement Program. MAIN OUTCOME MEASURES Percentages of clinical questions resolved by the autopsy and percentage of autopsies with unexpected findings of graded clinical impact. RESULTS In the aggregate database of 6427 questions from 2479 autopsies, overall 93.0% were answered by the autopsy. The 3 most common question categories were (1) identify pathology to account for clinical signs or symptoms (28.0%); (2) establish the cause of death (21.0%); and (3) confirm a clinical diagnosis (19.0%). At least one major unexpected disease finding that contributed to the patients death was discovered in 39.7% of the total number of autopsies. There were no differences in the percentages of autopsies with these major unexpected findings when the data were stratified by institutional demographics or decedent characteristics. CONCLUSION This multi-institutional study underscores the clinical relevance of postmortem examination in current medical practice by consistently providing answers to unresolved clinical questions and frequently revealing major unexpected findings that contributed to the patients death. It is our strong belief that this postmortem-derived clinicopathologic information is a key indicator of effectiveness of care. Integration of this information into institutional quality improvement programs will improve system processes and clinician performance.

Continuous Monitoring of Stat and Routine Outlier Turnaround Times: Two College of American Pathologists Q-Tracks Monitors in 291 Hospitals

CONTEXT The laboratory test turnaround times (TATs) that exceed the expectations of clinicians who order those tests, the so-called outlier test reporting rates, may be responsible for perceptions of inadequate laboratory service. OBJECTIVE To monitor outlier test reporting rates for emergency department stat potassium results and routine inpatient morning blood tests. DESIGN In 2 different monitors, each conducted for 2 years, laboratory personnel in institutions enrolled in the College of American Pathologists (CAP) Q-Tracks program tracked the percentages of emergency department stat potassium results and/or the percentages of morning rounds routine test results that were reported later than self-imposed reporting deadlines. SETTING A total of 291 hospitals participating in 2 CAP Q-Tracks monitors. RESULTS Participants monitored 225,140 stat emergency department potassium TATs, of which 33,402 (14.8%) were outliers, and 1,055040 routine morning test reporting times, of which 123,554 (11.7%) were outliers. For both monitors, there was a significant (P <.05) downward trend in the outlier rates as the number of quarters in which participants submitted data increased. CONCLUSION Outlier reporting rates for emergency department stat potassium and routine morning test results decreased during the 2-year period of continuous monitoring. The CAP Q-Tracks program provides an effective vehicle by which providers of laboratory services may improve the timeliness with which they deliver the results of laboratory tests.

Clinical laboratory quality control: a costly process now out of control

We studied laboratory internal quality control (QC) processes using the College of American Pathologists Q-Probes program. Over 500 institutions participated, providing practices based on approximately 710,000 cholesterol, 880,000 calcium, 400,000 digoxin, and 1,180,000 hemoglobin QC results. The costs of QC included participant median control samples rates comprising 9.1, 9.4, 37.0, and 6.8% for the four analytes respectively, repeat patient test rates of 0.36% for hemoglobin to 0.65% for digoxin, and median delays in reporting results when QC exceptions occurred of 15.8 min for calcium to 24.7 min for hemoglobin. Quality control practices were complex and highly variable among participants and frequently differed from internal laboratory protocols and from long-established quality guidelines. We conclude that QC is costly, and laboratorians frequently do not follow established QC practices, in part because they are complex. To improve compliance, we believe QC practices must be simplified.

Paraproteins are a common cause of interferences with automated chemistry methods.

CONTEXT Previous studies have shown that paraproteins caused spurious results on individual analytes including total bilirubin (TBIL), direct bilirubin (DBIL), or HDL-cholesterol (HDL-C). Studies demonstrating paraprotein interferences with multiple analytes measured by different analyzers have not been reported. OBJECTIVE To systemically investigate interferences of paraproteins on TBIL, DBIL, and HDL-C measured by the Roche MODULAR and the Olympus AU2700. DESIGN Eighty-eight serum specimens with monoclonal gammopathies were analyzed using the Roche MODULAR and the Olympus AU2700. Paraprotein interferences with the MODULAR and AU2700 were identified by abnormal absorbance curves and confirmed by results from the Ortho Vitros 950 or inconsistent laboratory information. RESULTS Spurious results occurred in 89 of 528 measurements; 29 specimens did not demonstrate any interferences whereas 26 specimens gave spurious results in 2 to 4 of the 6 assays. Paraprotein interferences caused spuriously high levels of TBIL in 4 sera measured by the MODULAR. In contrast, paraprotein interferences on DBIL were observed by at least 1 method in 44% (39/88) of sera assayed, occurring almost exclusively with the AU2700. Paraprotein interferences with HDL-C results were present in 35% of specimens assayed with the MODULAR and 16% of specimens assayed with the AU2700. In specimens with interferences, spuriously low AU2700 DBIL, MODULAR HDL-C, and AU2700 HDL-C results occurred with 28%, 90%, and 91% of specimens, respectively. CONCLUSIONS We demonstrated that paraprotein interferences with TBIL, DBIL, and HDL-C are relatively common and provided explanations why these interferences occurred. Although it is difficult to predict which specimens cause interferences, spurious results appeared method and concentration dependent.

Timeliness of automated routine laboratory tests: A College of American Pathologists Q-Probes study of 653 institutions

Benchmarks for timeliness of early morning routine clinical laboratory tests were developed from over 17,000 urea nitrogen and 16,000 white blood cell count measurements made for inpatients in 653 institutions participating in the College of American Pathologists Q-Probes program. Urea nitrogen and white blood cell counts were considered surrogates for routine chemistry and hematology tests. Laboratories at the 50th percentile reported median urea nitrogen and white blood cell counts by 09.04 and 08.51 h, respectively, whereas those at the 10th percentile reported these median measurements by 11.30 and 11.18 h, respectively. Results were available sooner in non-teaching than teaching institutions, and in smaller rather than larger institutions, with the degree of computerization affecting test availability. Timeliness also was affected by instrument type and mode of operation, but was unaffected by the percentage of stat testing. Based on modeling by regression analysis, there was little evidence that longer routine test turnaround times affect patient length of stay.