Assessment of operator performance during oocyte retrievals: residents’ learning curve and continuous monitoring of senior physicians

Background The learning curve cumulative summation test (LC CUSUM test) allows to define an individualized learning curve and determine the moment when clinical proficiency is attained. After acquisition of the skills, the cumulative summation test (CUSUM test) allows to monitor the maintenance of the required level over time. The LC CUSUM test has been frequently used in the field of Obstetrics and Gynecology (Ob/Gyn) for several procedures, but only once for OR. Methods We performed a retrospective study at Angers university hospital between May 2017 and September 2018. Seven Ob/Gyn residents and 5 senior physicians were included, and all OR performed during that time (n = 690) were analyzed. The performance index assessed was the oocyte retrieval rate (ORR), defined as the ratio of oocytes retrieved to follicles aspirated. We used the LC CUSUM test to analyze the learning curves of residents, and the CUSUM test to monitor the performance of senior physicians. An ORR ≥50% in 60% of retrievals was defined as the threshold for clinical proficiency. Results Six hundred seventy-four oocyte retrieval (OR) were included: 315 were performed by residents, 220 by senior physicians, and 139 by both residents and physicians (mixed retrievals). Four residents (57%) reached the threshold after aspirating 82, 67, 53 and 46 ovaries, respectively. The mean number of ovaries aspirated in order to reach clinical proficiency was 62, and the mean number of weeks needed was 21. The duration of the learning period varied between 26 and 80 days. Two senior physicians (40%) remained proficient across the duration of the study, while two physicians (40%) had one statistically “suboptimal” OR, and one physician (20%) had two suboptimal retrievals. Conclusion There is a large variability in the duration of the learning period and the number of procedures needed for a resident to master OR. Senior physicians maintain an adequate performance.

Quantitative and individualized assessment of the learning curve in preoperative planning of the acetabular cup size in primary total hip arthroplasty

Introduction The aim of the present study was to investigate the learning curves of 2 trainees with different experience levels to reach proficiency in preoperative planning of the cup size based on learning curve cumulative summation (LC-CUSUM) statistics and a cumulative summation (CUSUM) test. Materials and methods One-hundred-twenty patients who had undergone primary total hip arthroplasty with a cementless cup were selected. Preoperative planning was performed by an experienced orthopedic surgeon. Trainee 1 (student) and trainee 2 (resident) planned the cup size. The trainees were blinded to the preoperative plan and the definitive cup size. Only after a cup size was chosen, the trainees were unblinded to the preoperative plan of the surgeon. LC-CUSUM was applied to both trainees to determine when proficiency in determining the appropriate cup size was reached. A CUSUM test was applied to ensure retention of proficiency. Results With reference to the preoperative plan of the surgeon, LC-CUSUM indicated proficiency after 94 planning attempts for trainee 1 and proficiency after 66 attempts for trainee 2, respectively. Trainee 1 and 2 maintained proficiency thereafter. With reference to the definitive cup size, LC-CUSUM did not signal competency within the first 120 planning attempts for trainee 1. Trainee 2 was declared competent after 103 attempts and retained competency thereafter. Conclusions LC-CUSUM/CUSUM allow for an individualized, quantitative and continuous assessment of planning quality. Based on LC-CUSUM statistics, the two trainees of this study gain proficiency in planning of the acetabular cup size after 50–100 attempts when an immediate feedback is provided. Previous experience positively influences the performance. The study serves as basis for the medical education of students and residents in joint replacement procedures.

Comparison between bone alkaline phosphatase immunoassay and electrophoresis technique in hemodialysis patients

Summary Background Problem of the variability between the different methods using for bone alkaline phosphatase (bALP) determination greately influences the clinical significance of bALP as direct marker of bone metabolism. The aim of this study was to compare immunoassay with electrophoresis technique for bALP determination. Methods We measured bALP in 71 patients on hemodialysis with agar gel electrophoresis (ISO-PAL, SEBIA) and immunoassay (OSTASE, Beckman Coulter). Results The analyzed methods showed significant correlation (Spearman’s rho: 0.776, P < 0.01), but we found statistically significant (P < 0.01) positive bias (27%) for the results measured by immunoassay. In support of this, using electrophoresis technique we have detected presence of the intestinal isoenzymes of alkaline phosphatase in 55% of patients with median value of 30% of the total alkaline phoshatase and presence of liver-2 alkaline phosphatase isoform in 42% of patients with median value of 16.6%. The Kendall’s W of 0.787 (P<0.0001) revealed significant concordance between two analysed methods. Cusum test showed no significant deviation from linearity (P=0.850). Conclusions Despite good agreement between immunoassay methods and electrophoresis technique for bALP determination, interchangeability between these two methods is questionable. Although immunoassays are increasingly used, as fully automated methods, in a large number of laboratories and become routine methods for bALP determination, it should be beared in mind, besides various interferences, also the heterogeneity of the bALP itself, especially in patients on hemodialysis.

Analytical evaluation of the new Seal Autoanalyzer 3 High Resolution for urinary iodine determination

Introduction: The aim of the study was to evaluate the analytical performance of the new colorimetric, automatic analyser, Seal AutoAnalyzer 3 High Resolution (Seal AA3 HR) (Seal Analytical, Wisconsin, USA) for urinary iodine measurement. Materials and methods: This study included testing of several analytical features of the method involving: imprecision (within-run %CVr, between- run %CVb and total laboratory precision %CVl), measurement uncertainty, carryover, linearity and method comparison, with 70 urine samples including the measuring range (20 - 700 μg/L). Results: Within-run, %CVb and %CVl of two control levels were 2.03% and 3.04%, 0.51% and 2.61%, and 2.09% and 4.01%, respectively. Carryover effect was less than 1%. The linearity was good in the range of urinary iodine values between 60 and 500 μg/L (R2 = 0.99). Good agreement of urinary iodine values was found between manual technique and Seal AA3 HR, using Passing-Bablok regression (y = 7.84 (- 3.00 to 15.29) + 0.95 (0.90 to 1.00) x) and Blant-Altman test. Cusum test for linearity indicates that there is no significant deviation from linearity (P > 0.1). Conclusions: The obtained results proved excellent precision, reproducibility and linearity, comparable to the already used, manual method. The New Seal AA3 HR automatic analyser is acceptable for urinary iodine measurement with very good analytical characteristics and can be used for urinary iodine epidemiological studies of the Croatian population.

An Examination of Malaysia’s Structural Breaks Vis-À-Vis Japan and the USA

This paper primarily examines whether Malaysia has had experienced any structural breaks in comparison with its main two trading partners, namely the USA and Japan in 1970s, 1980s, 1990s and 2000s. It also discusses the implications of such structural breaks to Malaysia’s economic globalization at the international level. Using some econometric and statistical tools such as the ADF test, transformed lag equation, Chow Breakpoint test, and CUSUM test, the study reveals that only at 1% level of significance income ratio of Japan and Malaysia has had experienced structural breaks in terms of GDP during the periods 1980s, 1990s, and 2000s. In respect of GNI, the study reveals that only at 5% level of significance their income ratio has had experienced structural breaks during these periods. The study further reveals that income ratio of the USA and Malaysia does not have any structural break both in respect of GNI and GDP.