Distribution Of Critical Values Research Articles

To Repeat or Not to Repeat: An Evaluation of Critical Values in Chemistry Laboratory Testing

Abstract It is common laboratory practice to repeat critical values before reporting the result. However, the benefits of repeat testing are unclear. There are slight differences in values whenever tests are repeated, owing to the inherent imprecision of instruments. Repeating critical values delays reporting of results and, ultimately, clinical intervention. Modern instruments have ultrasensitive level sensors, clot detectors, and better precision, making this practice costly and clinically inefficient. This study aimed to evaluate critical values pairs (original and repeats) to determine if repeats were necessary. Our instruments are programmed to automatically repeat critical values for several analytes. In total, 3,891 critical value pairs (potassium, n = 1111; sodium, n = 677; glucose, n = 987; calcium, n = 214; phosphorus, n = 86; magnesium, n = 399; and bicarbonate/CO2, n = 417) that were performed from April to July 2018 at our core laboratory were analyzed. Data were extracted using software developed to evaluate clinical laboratory data for quality assurance. Analysis of the distribution of critical values within and outside the analytical measurement range (AMR) for each of the analytes was performed. The repeat pairs were analyzed for significant differences (>CAP allowable error), mean absolute and percentage difference between the two determinations, and the number of results that were no longer critical on repeat testing. A cost-time analysis was also performed. For all critical values, a total of 49 (1.26%) showed significant differences between the initial and the repeated results. There were significant differences in 35 (0.92%) of the 3,800 repeats within and in 14 (15.38%) of the 91 repeats outside the AMR. For the 3,800 critical values within the AMR, the mean absolute difference and percent difference between the two testing determinations were: potassium, 0.02 mmol/L (0.42%); sodium, 0.19 mmol/L (0.13%); glucose, 0.44 mg/dL (0.16%); calcium, 0.01 mg/dL (0.14%); phosphorus, 0.01 mg/dL (0.16%); magnesium, 0.01 mg/dL (0.31%); and bicarbonate (CO2), 0.57 mEq/L (1.73%), respectively. A total of 254 (6.53%) initial critical values turned out to be noncritical when repeated, although most were just above or below the cutoff. During the study period, the analytical time for critical value repeats was around 355 hours and the cost was just over $1,300. Data from our study suggest that repeated testing is very similar to the original result and therefore redundant. A higher percentage of results had a significant difference when outside the AMR and repeating just these results can be considered. This study did not capture results that were just below or above the critical value cutoffs, and several of these would have likely been critical on repeat testing. Our analysis suggests that these chemistry critical values should not be routinely repeated, allowing for potential cost savings and improved patient care by reporting critical values sooner, resulting in faster clinical intervention.

Analysis of Laboratory Critical value Reporting Pattern at clinical biochemistry laboratory of Tertiary health care Center

Objectives: Objective of the study is to analyze critical value reporting data to find frequency of critical reporting, distribution of critical values across reportable range and across hospital segments and reasons for failure in critical reporting. Material & Method: The critical value reporting data for various analysts were collected from LIS for 1 year. The data were analyzed in computer spreadsheets. Result & Discussion: Of 548786 test results analyzed, about 10% results were critical. Total Billirubin (20.14 %), Indirect Billirubin (18 %), Glucose (18%) and Sodium (13.6 %),Potassium (11.8%) contributed most to the critical values. 29% of urea, 13.29 % of Glucose ,15.37% of Indirect Billirubin, 13.71% of Sodium, 13.29% of Glucose & 11.6 % of total analyzed potassium were critical. On a per test basis, inpatient tests were 3.6 times more likely to result in a critical callback than outpatient tests. The number of critical values per year per bed was 176.34 for ICU beds and 29.36 for non-ICU beds and 5.0 for Emergency Department. Conclusion: The high proportion of reported critical value of urea is due to practice of reflex testing in the laboratory whenever Creatinine is in abnormal range. The high proportion of reported critical value of Indirect Billirubin is due to present of PICU, NICU in Hospital. Major reasons for failure of notification of critical alert are incomplete detail on request form, transfer of patient to Ward or ICU, phone is engaged or phone not picked up by care giver.

Study on the application of critical laboratory values

Objective By analysing the historical data of critical laboratory values,the development of practicable critical values reporting system was investigated. Methods There were totally 63 794 critical values reported by the Department of Laboratory Medicine of the First Affiliated Hospital of Fujian Medical University from Nov,2008 to Oct,2012.We analysed the yearly incidence,the analytes and the distribution of critical values; we also compared the report timeliness and false rejection rate before and after the informationization and differential management of the critical values report; Meanwhile we compared the clinician response time before and after the implementation of the new out-patients critical values reporting flow. Results There were 15 000-18 000 critical values reports yearly accounting for 1.53% (63 794/4 166 267) of the total results.Most of the critical values reports were from in-patients (about 80%),and the top 3 analytes of critical values were PLT, K+ and APTT.The critical values reports were not uniformly distributed the ICU Department,Hematology Department,Emergence Department and Liver Center were concentrated distribution departments.It took 3-8 minutes (median:5 min) for staff in the Department of Laboratory Medicine to call the clinician/nurse after critical values were known and the false rejection rate was 7.53% (949/12 596).However,it just took 5-10 s to notify the clinician/nurse via the electronic alert system,and the false rejection rate was 0.There was a significant decrease of critical values reports about the in-patients in the Hematology Department and the Liver Center since the definition of critical values in these two departments was slightly modified,that was from 13.85% to 11.24% (the Hematology Department) and from 12.77% to 8.43% (the Liver Center),respectively.And since the new out-patients critical values reporting flow was adopted (different reporting flows during office hours and out of hours),the clinician response time decreased from 20 min to 7 min. Conclusions The informationization of the critical values report is helpful to improve work efficiency and the accuracy rate.And the hospital should make practicable critical values reporting system on the basis of individual institutional needs,especially the out-patient critical values reporting flow.(Chin J Lab Med,2013,36:565-568) Key words: Clinical laboratory information systems; Reference values; Reference standards; Hospital administration