Value and Use of Urinalysis for Myoglobinuria.

CONTEXT.­: Urine myoglobin testing is primarily indicated for diagnosis and risk assessment of kidney injury in patients with rhabdomyolysis. However, its utility is limited by a lack of rapid and reliable results. Myoglobin reacts positively for blood by urine dipstick, which can serve as an indicator of myoglobinuria. OBJECTIVE.­: To evaluate the performance and value of blood and red cell measurements by urinalysis as a surrogate test for myoglobinuria in routine clinical practice. DESIGN.­: This study is a retrospective observational study involving analysis of hemoglobin and red blood cell results by urinalysis in patients tested for urine myoglobin. RESULTS.­: A total of 13 139 urine myoglobin results from 88 Veterans Affairs facilities during a 15-year period ending in October 2014 were evaluated. Among methods used by each laboratory, qualitative urine myoglobin tests declined from 25 of 53 (47.1%) in 2000 to 5 of 77 (6.4%) in 2013. Of 7311 tests (55.6%) performed by quantitative methods with concomitant urinalysis, 3915 (53.5%) showed negative to trace blood results, of which myoglobin was 1000 µg/L or greater in 17 (0.4%). Among 1875 (25.5%) with 3+ (large) blood results, urine myoglobin was ≥1000 µg/L in 273 of 1533 (17.8%) with hematuria (≥5 red blood cells per microliter) and 109 of 342 (31.9%) without hematuria. CONCLUSIONS.­: Urinalysis results reliably predicted the absence of myoglobinuria and could be used to avert overtesting for urine myoglobin while also providing useful diagnostic information when urine myoglobin test results are not immediately available.

A Q-Probes Study Involving Utilization of Free Prostate-Specific Antigen, Factor V Leiden, and Hepatitis A Serology Tests.

CONTEXT.­: Managing the utilization of laboratory tests is an important quality improvement activity that adds value to health care. OBJECTIVE.­: To examine utilization of 3 laboratory tests and identify factors that impact performance. DESIGN.­: Test utilization performance was evaluated by determining the frequency with which appropriate preconditions for testing were met. This included 30 testing episodes each involving (1) free prostate-specific antigen (PSA) when total PSA was within an appropriate interpretable range, (2) total anti-hepatitis A virus antibody when previous anti-hepatitis A virus antibody results were either negative or not done, and (3) factor V Leiden mutation when a previous result was not already available. Participants also provided information regarding some of their utilization policies and procedures for these 3 tests. RESULTS.­: The overall frequency with which testing criteria were met was 20.6% (163 of 790), 91.5% (649 of 709), and 95.2% (799 of 839) for free PSA, anti-hepatitis A virus antibody, and factor V Leiden, respectively. Utilization review was infrequent and done by 20.7% (6 of 29) of participants for factor V Leiden, 3.6% (1 of 28) for anti-hepatitis A virus antibody, and 3.6% (1 of 28) for free PSA. No practice or demographic characteristics were significantly associated with utilization performance for any test. CONCLUSIONS.­: Utilization review was infrequent for the 3 tests examined. Variable amounts of unnecessary testing were observed for all tests, most frequently for free PSA, for which reporting results carried the added risk of diagnostic error from misinterpretation of results.

Aluminum Toxicity: Evaluation of 16-Year Trend Among 14 919 Patients and 45 480 Results.

CONTEXT: - Annual monitoring with serum aluminum measurements is recommended for dialysis patients who are susceptible to toxic accumulation from contaminated dialysis fluid or from ingestion of aluminum-containing medications. OBJECTIVE: - To evaluate long-term trends in serum aluminum concentrations and frequency of chronic toxicity. DESIGN: - A retrospective observational study was conducted by analyzing serum aluminum results obtained from the Veterans Affairs corporate data warehouse. Serum aluminum concentrations of 60 µg/L or greater were considered false positives and not indicative of chronic toxicity if another specimen retested within 45 days had a concentration below 20 µg/L. RESULTS: - A total of 45 480 serum aluminum results involving 14 919 patients and 119 Veteran Affairs facilities during a 16-year period ending in October 2016 were evaluated. The percentage of elevated (≥20 µg/L) serum aluminum results declined from 31.5% in 2000 to 2.0% in 2015. Average testing intervals changed from every 159 days in 2000 to every 238 days in 2015. Of 529 patients with serum aluminum concentrations of 60 µg/L or greater, 216 (40.8%) were retested within 45 days (average = 21 days); of these, 83 (38.4%) had concentrations below 20 µg/L after repeated measurements. Retesting rates increased with higher initial serum aluminum concentrations. CONCLUSIONS: - Aluminum toxicity, as assessed by serum levels, has substantially declined over time and is now rare. Many serum aluminum concentrations in the toxic range were not confirmed after retesting. Patients with toxic serum aluminum concentrations should be retested with another specimen before undergoing treatment or investigating sources of exposure to verify abnormal results.

Delta Check Practices and Outcomes: A Q-Probes Study Involving 49 Health Care Facilities and 6541 Delta Check Alerts.

CONTEXT: - Delta checks serve as a patient-based quality control tool to detect testing problems. OBJECTIVE: - To evaluate delta check practices and outcomes. DESIGN: - Q-Probes participants provided information about delta check policies and procedures. Information about investigations, problems, and corrective actions was prospectively collected for up to 100 testing episodes involving delta check alerts. RESULTS: - Among 4505 testing episodes involving 6541 delta check alerts, the median frequencies of actions taken among 49 laboratories were clinical review, 38.0%; retest, 25.0%, or recheck, 20.2%; current specimen, nothing, 15.4%; analytical check, 5.0%; other; 2%; and retest or check previous specimen, 0%. Rates of any action taken by analyte ranged from 84 of 179 (46.9%) for glucose to 748 of 868 (86.2%) for hemoglobin and potassium. Among 4505 testing episodes, nontesting problems included physiologic causes (1472; 32.7%); treatment causes (1318; 19.2%); and transfusion causes (846; 9.9%). Testing problems included 77 interference (1.7%), 62 contamination (1.4%), 51 clotting (1.1%), 27 other (0.6%), 12 mislabeling (0.3%), and 5 analytical (0.1%). Testing problems by analyte ranged from 13 of 457 (2.8%) for blood urea nitrogen to 12 of 46 (26.1%) for mean corpuscular hemoglobin concentration. Using more delta check analytes was associated with detecting more testing problems (P = .04). More delta check alerts per testing episode resulted in more actions taken (P = .001) and more problems identified (P < .001). The most common outcome among 4500 testing episodes was reporting results without modifications or comments in 2512 (55.8%); results were not reported in 136 (3.0%). CONCLUSIONS: - Actions taken in response to delta check alerts varied widely, and most testing problems detected were preanalytical. Using a higher number of different analytes and evaluating previous specimens may improve delta check practices.

Point-of-Care Glucose Critical Values: A Q-Probes Study Involving 50 Health Care Facilities and 2349 Critical Results.

CONTEXT: Accuracy of blood glucose measurements in the critical value range is important for properly treating patients with severe hypoglycemia and hyperglycemia. OBJECTIVE: To evaluate the performance and reliability of point-of-care glucose (POCG) results in the critical value range among multiple facilities. DESIGN: Q-Probes participants retrospectively collected data from up to 50 POCG results in their critical value range including patient location, type of testing operator, repeat glucose results, and caregiver notification. A repeat measurement at 10 minutes or less that was within 15 mg/dL of initial critical low or 20% of initial critical high value was considered a confirmed result. RESULTS: Fifty facilities submitted data. Of 2349 critical POCG measurements, 1386 (59.0%) were retested. The median institutional retest rate was 56%. The retest rate was significantly higher when initial results were in the critical low range, P < .001. Although 30 of 50 facilities (60%) had written procedures for retesting, this was not associated with higher retest rates (P = .34). Among 35 facilities that routinely retested critical POCG results, 23 (65.7%) had criteria defined for interpreting results. The median institutional confirmation rate for retested specimens was 81.7%. The median institutional rate for caregiver notification of critical POCG results was 85.7%. Five hundred eighty-six of 1488 critical POCG notifications (39.4%) were done on patients in whom specimens were not retested. CONCLUSIONS: This study shows that POCG results in the critical range may be unreliable because of testing errors that are not recognized from lack of confirmatory testing. In addition, notification of critical POCG results is not consistently performed.

Seven Q-Tracks monitors of laboratory quality drive general performance improvement: experience from the College of American Pathologists Q-Tracks program 1999-2011.

CONTEXT: Many production systems employ standardized statistical monitors that measure defect rates and cycle times, as indices of performance quality. Clinical laboratory testing, a system that produces test results, is amenable to such monitoring. OBJECTIVE: To demonstrate patterns in clinical laboratory testing defect rates and cycle time using 7 College of American Pathologists Q-Tracks program monitors. DESIGN: Subscribers measured monthly rates of outpatient order-entry errors, identification band defects, and specimen rejections; median troponin order-to-report cycle times and rates of STAT test receipt-to-report turnaround time outliers; and critical values reporting event defects, and corrected reports. From these submissions Q-Tracks program staff produced quarterly and annual reports. These charted each subscriber's performance relative to other participating laboratories and aggregate and subgroup performance over time, dividing participants into best and median performers and performers with the most room to improve. Each monitor's patterns of change present percentile distributions of subscribers' performance in relation to monitoring durations and numbers of participating subscribers. Changes over time in defect frequencies and the cycle duration quantify effects on performance of monitor participation. RESULTS: All monitors showed significant decreases in defect rates as the 7 monitors ran variously for 6, 6, 7, 11, 12, 13, and 13 years. The most striking decreases occurred among performers who initially had the most room to improve and among subscribers who participated the longest. All 7 monitors registered significant improvement. Participation effects improved between 0.85% and 5.1% per quarter of participation. CONCLUSIONS: Using statistical quality measures, collecting data monthly, and receiving reports quarterly and yearly, subscribers to a comparative monitoring program documented significant decreases in defect rates and shortening of a cycle time for 6 to 13 years in all 7 ongoing clinical laboratory quality monitors.

Timeliness and accuracy of reporting preliminary blood culture results: a College of American Pathologists Q-probes study of 65 institutions.

CONTEXT: The speed and accuracy of preliminary blood culture reports impacts patient management and outcomes. OBJECTIVE: To evaluate the accuracy and timeliness of preliminary blood culture results among multiple laboratories. DESIGN: Q-Probes participants collected turnaround time (TAT) data on preliminary Gram stains, compared accuracy of up to 100 preliminary to final culture Gram stain results, and described blood culture laboratory practices. RESULTS: Sixty-four laboratories and 5031 blood cultures were evaluated. All participants used continuously monitoring blood culture systems. Median TAT from initial growth detection to notification of results was 45 minutes, with the longest component being preparation of Gram stains (median time = 25 minutes). Participants (N = 40) reporting a continuous schedule for processing blood cultures had significantly lower overall TAT (median= 37 minutes) compared with 15 participants with intermittent processing schedules (median= 124 minutes), P= .003. Time to complete Gram stain processing was lower (median time = 21 minutes) for 39 participants using continuous processing schedule compared with 14 others (median time= 67 minutes), P= .03. Goals for total TAT were used by 27 of 56 participants (48.2%). Having goals did not significantly affect TAT. A total of 4962 of 5021 Gram stain results (98.8%) agreed with final culture results. The highest discrepancy rates occurred among gram-positive bacilli (20 of 335; 6.0%) and mixed cultures (22 of 106; 20.8%). CONCLUSIONS: This study provides benchmarks for assessing blood culture quality performance. Timeliness and accuracy of preliminary blood culture reports were excellent. However, nearly one-third of laboratories did not process blood cultures continuously. This significantly prolonged reporting results, which could affect patient outcomes.

Reliability of point-of-care capillary blood glucose measurements in the critical value range.

CONTEXT: Point-of-care glucose (POCG) testing on capillary blood specimens is central to maintaining glycemic control in patients with diabetes. Although there are known performance issues with POCG methods, especially for maintaining tight glucose control, there is little information about the accuracy of results in the critical ranges that may involve life-threatening conditions. OBJECTIVES: To evaluate the reliability of POCG measurements in critical, high (>600 mg/dL) and low (<40 mg/dL) ranges. DESIGN: One-year retrospective analysis of POCG (ACCU-CHEK glucose meter, Roche Diagnostics Corporation, Indianapolis, Indiana) results for routine patient care were obtained. The frequency and accuracy of repeat testing after critical POCG results was analyzed. A convenience sample of noncritical capillary POCG measurements retested on venous blood specimens by another point-of-care device (RAPIDPoint 405 analyzer, Siemens Medical Solutions USA, Malvern, Pennsylvania) was also evaluated. RESULTS: Critical values were observed in 2.4 per 1000 POCG tests (256 of 105,928; 0.24%), with the highest rate (76 of 2289; 3.32%) from the emergency department. Twice as many critical high values as critical low values were seen. Nearly 80% of critical POCG tests (204 of 256) were repeated within 10 minutes. Of these 204 repeat measurements, 112 (54.9%) met accuracy criteria (±15 mg/dL of low and ±20% of high initial values). Accuracy was significantly higher when retesting was performed on the same meter or by the same operator (P ≤ .05). Comparison of capillary and venous POCG testing of noncritical results showed no significant difference (P = .95), with 89.8% (125 of 139) meeting accuracy criteria. CONCLUSIONS: POCG measurements in the critical range are frequently erroneous, which is likely caused by preanalytic factors associated with sampling capillary blood. POCG testing practices should include retesting to confirm critical results.

Q-tracks: a College of American Pathologists program of continuous laboratory monitoring and longitudinal 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 decade's 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.